Lincoln Electric Welding System SVM 119 A User Manual

SVM 119-A  
January 1996  
WIRE-MATIC 255  
For use with machines having Code Numbers:  
10166,  
10167.  
Safety Depends on You  
Lincoln arc welding and cutting  
equipment is designed and built  
with safety in mind. However,  
your overall safety can be  
increased by proper installation  
... and thoughtful operation on  
your part. DO NOT INSTALL,  
OPERATE OR REPAIR THIS  
EQUIPMENT WITHOUT READ-  
ING THIS MANUAL AND THE  
SAFETY PRECAUTIONS CON-  
TAINED THROUGHOUT. And,  
most importantly, think before you  
act and be careful.  
VOLTS  
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WIRE SPEED  
300  
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WIRE-MATIC 255  
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SERVICE MANUAL  
World's Leader in Welding and Cutting Products  
Premier Manufacturer of Industrial Motors  
Sales and Service through Subsidiaries and Distributors Worldwide  
22801 St. Clair Ave. Cleveland, Ohio 44117-1199 U.S.A. Tel. (216) 481-8100  
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ii  
ii  
SAFETY  
WELDING SPARKS can  
cause fire or explosion.  
CYLINDER may explode  
if damaged.  
4.a. Remove fire hazards from the welding area.  
If this is not possible, cover them to prevent  
5.a. Use only compressed gas cylinders  
containing the correct shielding gas for the  
the welding sparks from starting a fire.  
Remember that welding sparks and hot  
materials from welding can easily go through small cracks  
and openings to adjacent areas. Avoid welding near  
hydraulic lines. Have a fire extinguisher readily available.  
process used and properly operating  
regulators designed for the gas and  
pressure used. All hoses, fittings, etc. should be suitable for  
the application and maintained in good condition.  
5.b. Always keep cylinders in an upright position securely  
chained to an undercarriage or fixed support.  
4.b. Where compressed gases are to be used at the job site,  
special precautions should be used to prevent hazardous  
situations. Refer to “Safety in Welding and Cutting” (ANSI  
Standard Z49.1) and the operating information for the  
equipment being used.  
5.c. Cylinders should be located:  
Away from areas where they may be struck or subjected to  
physical damage.  
4.c. When not welding, make certain no part of the electrode  
circuit is touching the work or ground. Accidental contact can  
cause overheating and create a fire hazard.  
•A safe distance from arc welding or cutting operations and  
any other source of heat, sparks, or flame.  
5.d. Never allow the electrode, electrode holder or any other  
electrically “hot” parts to touch a cylinder.  
4.d. Do not heat, cut or weld tanks, drums or containers until the  
proper steps have been taken to insure that such procedures  
will not cause flammable or toxic vapors from substances  
inside. They can cause an explosion even though they have  
been “cleaned”. For information, purchase “Recommended  
Safe Practices for the Preparation for Welding and Cutting of  
Containers and Piping That Have Held Hazardous  
Substances”, AWS F4.1 from the American Welding Society  
(see address above).  
5.e. Keep your head and face away from the cylinder valve outlet  
when opening the cylinder valve.  
5.f. Valve protection caps should always be in place and hand  
tight except when the cylinder is in use or connected for  
use.  
5.g. Read and follow the instructions on compressed gas  
cylinders, associated equipment, and CGA publication P-l,  
“Precautions for Safe Handling of Compressed Gases in  
Cylinders,” available from the Compressed Gas Association  
1235 Jefferson Davis Highway, Arlington, VA 22202.  
4.e. Vent hollow castings or containers before heating, cutting or  
welding. They may explode.  
4.f. Sparks and spatter are thrown from the welding arc. Wear oil  
free protective garments such as leather gloves, heavy shirt,  
cuffless trousers, high shoes and a cap over your hair. Wear  
ear plugs when welding out of position or in confined places.  
Always wear safety glasses with side shields when in a  
welding area.  
FOR ELECTRICALLY  
powered equipment.  
4.g. Connect the work cable to the work as close to the welding  
area as practical. Work cables connected to the building  
framework or other locations away from the welding area  
increase the possibility of the welding current passing  
through lifting chains, crane cables or other alternate circuits.  
This can create fire hazards or overheat lifting chains or  
cables until they fail.  
6.a. Turn off input power using the disconnect  
switch at the fuse box before working on  
the equipment.  
6.b. Install equipment in accordance with the U.S. National  
Electrical Code, all local codes and the manufacturer’s  
recommendations.  
4.h. Also see item 7c.  
6.c. Ground the equipment in accordance with the U.S. National  
Electrical Code and the manufacturer’s recommendations.  
Feb. ‘95  
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iii  
iii  
SAFETY  
FOR ENGINE  
ELECTRIC AND MAG-  
NETIC FIELDS  
may be dangerous  
powered equipment.  
7.a. Turn the engine off before troubleshooting and maintenance  
work unless the maintenance work requires it to be running.  
____________________________________________________  
8.a. Electric current flowing through any conductor causes  
localized Electric and Magnetic Fields (EMF). Welding  
current creates EMF fields around welding cables and  
welding machines  
7.b. Operate engines in open, well-ventilated  
areas or vent the engine exhaust fumes  
outdoors.  
8.b. EMF fields may interfere with some pacemakers, and  
welders having a pacemaker should consult their physician  
before welding.  
____________________________________________________  
8.c. Exposure to EMF fields in welding may have other health  
effects which are now not known.  
7.c. Do not add the fuel near an open flame  
welding arc or when the engine is run-  
ning. Stop the engine and allow it to cool  
before refueling to prevent spilled fuel  
from vaporizing on contact with hot  
engine parts and igniting. Do not spill  
fuel when filling tank. If fuel is spilled,  
wipe it up and do not start engine until  
fumes have been eliminated.  
8d. All welders should use the following procedures in order to  
minimize exposure to EMF fields from the welding circuit:  
8.d.1. Route the electrode and work cables together - Secure  
them with tape when possible.  
8.d.2. Never coil the electrode lead around your body.  
____________________________________________________  
8.d.3. Do not place your body between the electrode and  
work cables. If the electrode cable is on your right  
side, the work cable should also be on your right side.  
7.d. Keep all equipment safety guards, covers  
and devices in position and in good repair.  
Keep hands, hair, clothing and tools away  
from V-belts, gears, fans and all other  
moving parts when starting, operating or  
repairing equipment.  
8.d.4. Connect the work cable to the workpiece as close as  
possible to the area being welded.  
8.d.5. Do not work next to welding power source.  
____________________________________________________  
Mar. ‘93  
7.e. In some cases it may be necessary to remove safety  
guards to perform required maintenance. Remove  
guards only when necessary and replace them when the  
maintenance requiring their removal is complete.  
Always use the greatest care when working near moving  
parts.  
7.f. Do not put your hands near the engine fan. Do not  
attempt to override the governor or idler by pushing on  
the throttle control rods while the engine is running.  
7.g. To prevent accidentally starting gasoline engines while  
turning the engine or welding generator during maintenance  
work, disconnect the spark plug wires, distributor cap or  
magneto wire as appropriate.  
___________________________________________________  
7.h. To avoid scalding, do not remove the  
radiator pressure cap when the engine is  
hot.  
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iv  
iv  
SAFETY  
zones où l’on pique le laitier.  
PRÉCAUTIONS DE SÛRETÉ  
6. Eloigner les matériaux inflammables ou les recouvrir afin de  
prévenir tout risque d’incendie dû aux étincelles.  
Pour votre propre protection lire et observer toutes les instructions  
et les précautions de sûreté specifiques qui parraissent dans ce  
manuel aussi bien que les précautions de sûreté générales suiv-  
antes:  
7. Quand on ne soude pas, poser la pince à une endroit isolé de  
la masse. Un court-circuit accidental peut provoquer un  
échauffement et un risque d’incendie.  
Sûreté Pour Soudage A L’Arc  
1. Protegez-vous contre la secousse électrique:  
8. S’assurer que la masse est connectée le plus prés possible de  
la zone de travail qu’il est pratique de le faire. Si on place la  
masse sur la charpente de la construction ou d’autres endroits  
éloignés de la zone de travail, on augmente le risque de voir  
passer le courant de soudage par les chaines de levage,  
câbles de grue, ou autres circuits. Cela peut provoquer des  
risques d’incendie ou d’echauffement des chaines et des  
câbles jusqu’à ce qu’ils se rompent.  
a. Les circuits à l’électrode et à la piéce sont sous tension  
quand la machine à souder est en marche. Eviter toujours  
tout contact entre les parties sous tension et la peau nue  
ou les vétements mouillés. Porter des gants secs et sans  
trous pour isoler les mains.  
b. Faire trés attention de bien s’isoler de la masse quand on  
soude dans des endroits humides, ou sur un plancher met-  
allique ou des grilles metalliques, principalement dans  
les positions assis ou couché pour lesquelles une grande  
partie du corps peut être en contact avec la masse.  
c. Maintenir le porte-électrode, la pince de masse, le câble de  
soudage et la machine à souder en bon et sûr état defonc-  
tionnement.  
9. Assurer une ventilation suffisante dans la zone de soudage.  
Ceci est particuliérement important pour le soudage de tôles  
galvanisées plombées, ou cadmiées ou tout autre métal qui  
produit des fumeés toxiques.  
10. Ne pas souder en présence de vapeurs de chlore provenant  
d’opérations de dégraissage, nettoyage ou pistolage. La  
chaleur ou les rayons de l’arc peuvent réagir avec les vapeurs  
du solvant pour produire du phosgéne (gas fortement toxique)  
ou autres produits irritants.  
d.Ne jamais plonger le porte-électrode dans l’eau pour le  
refroidir.  
e. Ne jamais toucher simultanément les parties sous tension  
des porte-électrodes connectés à deux machines à soud-  
er parce que la tension entre les deux pinces peut être le  
total de la tension à vide des deux machines.  
11. Pour obtenir de plus amples renseignements sur la sûreté, voir  
le code “Code for safety in welding and cutting” CSA Standard  
W 117.2-1974.  
f. Si on utilise la machine à souder comme une source de  
courant pour soudage semi-automatique, ces precautions  
pour le porte-électrode s’applicuent aussi au pistolet de  
soudage.  
2. Dans le cas de travail au dessus du niveau du sol, se protéger  
contre les chutes dans le cas ou on recoit un choc. Ne jamais  
enrouler le câble-électrode autour de n’importe quelle partie  
du corps.  
PRÉCAUTIONS DE SÛRETÉ POUR  
LES MACHINES À SOUDER À  
TRANSFORMATEUR ET À  
REDRESSEUR  
3. Un coup d’arc peut être plus sévère qu’un coup de soliel,  
donc:  
a. Utiliser un bon masque avec un verre filtrant approprié  
ainsi qu’un verre blanc afin de se protéger les yeux du ray-  
onnement de l’arc et des projections quand on soude ou  
quand on regarde l’arc.  
1. Relier à la terre le chassis du poste conformement au code de  
l’électricité et aux recommendations du fabricant. Le dispositif  
de montage ou la piece à souder doit être branché à une  
bonne mise à la terre.  
b. Porter des vêtements convenables afin de protéger la  
peau de soudeur et des aides contre le rayonnement de  
l‘arc.  
2. Autant que possible, I’installation et l’entretien du poste seront  
effectués par un électricien qualifié.  
c. Protéger l’autre personnel travaillant à proximité au  
soudage à l’aide d’écrans appropriés et non-inflammables.  
3. Avant de faires des travaux à l’interieur de poste, la debranch-  
er à l’interrupteur à la boite de fusibles.  
4. Des gouttes de laitier en fusion sont émises de l’arc de  
soudage. Se protéger avec des vêtements de protection libres  
de l’huile, tels que les gants en cuir, chemise épaisse, pan-  
talons sans revers, et chaussures montantes.  
4. Garder tous les couvercles et dispositifs de sûreté à leur  
place.  
5. Toujours porter des lunettes de sécurité dans la zone de  
soudage. Utiliser des lunettes avec écrans lateraux dans les  
Mar. ‘93  
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NOTES  
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v
v
TABLE OF CONTENTS  
Page  
Safety  
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .i - v  
Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Section A  
Technical Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .A-1  
Safety Precautions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .A-2  
Select Proper Location . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .A-2  
Input Connections . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .A-2  
Reconnect Procedure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .A-5  
Connect Output Components . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .A-7  
Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Section B  
Safety Instructions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .B-1  
General Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .B-1  
Recommended Processes and Equipment . . . . . . . . . . . . . . . . . . . . . . .B-2  
Design Features and Advantages . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .B-2  
Machine Capability . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .B-3  
Limitations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .B-3  
Controls and Settings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .B-4  
Using the Wire Drive Roll . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .B-5  
Operating Steps . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .B-7  
Accessories . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Section C  
Other Available Magnum 250L Gun and Cable Assembly . . . . . . . . . . . .C-1  
Magnum Gun Connection Kit (Optional K466-6) . . . . . . . . . . . . . . . . . . .C-1  
K672-1 Spool Gun Adapter Kit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .C-1  
Making a Weld with the Spool Gun Adapter and Spool Gun  
(K672-1) Installed . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .C-1  
Making a Weld with the Spool Gun Adapter (K672-1) Installed . . . . . . . .C-2  
Timer Kit (K585-1) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .C-3  
Timer Kit Installation (Optional K585-1) . . . . . . . . . . . . . . . . . . . . . . . . . .C-3  
Making Spot and Stitch Welds with Timer Kit Installed . . . . . . . . . . . . . . .C-4  
Drive Roll Kits . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .C-4  
3/64” Aluminum Feeding Kit (K673-1) . . . . . . . . . . . . . . . . . . . . . . . . . . .C-4  
K468 8” Spool Adapter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .C-4  
K363P Readi-Reel Adapter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .C-4  
Dual Cylinder Mounting (K671-1) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .C-5  
Maintenance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Section D  
Safety Precautions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .D-1  
Routine and Periodic Maintenance . . . . . . . . . . . . . . . . . . . . . . . . . . . . .D-1  
Component Locations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .D-2  
Drive Rolls and Guide Tubes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .D-3  
Cable Cleaning . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .D-3  
Gun Tubes and Nozzles . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .D-3  
Contact Tip and Gas Nozzle Installation . . . . . . . . . . . . . . . . . . . . . . . . .D-3  
Liner Removal and Replacement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .D-4  
Liner Removal, Installation, and Trimming Instructions for Magnum 250L D-4  
Gun Handle Disassembly . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .D-5  
Accessories and Expendable Replacement Parts for  
Magnum 250L Gun and Cable Assemblies . . . . . . . . . . . . . . . . . . . .D-6  
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vi  
vi  
TABLE OF CONTENTS (continued)  
Page  
Theory of Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Section E  
Power Supply Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .E-1  
Thermal Protection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .E-5  
SCR Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .E-6  
Troubleshooting and Repair . . . . . . . . . . . . . . . . . . . . . . . . . . . . Section F  
How to use Troubleshooting Guide . . . . . . . . . . . . . . . . . . . . . . . . . . . . .F-1  
PC Board Troubleshooting Procedures . . . . . . . . . . . . . . . . . . . . . . . . . .F-2  
Troubleshooting Guide . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .F-3  
Test Procedures . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .F-10  
Oscilloscope Waveforms . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .F-22  
Replacement Procedures . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .F-27  
Electrical Diagrams . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Section G  
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INSTALLATION  
TABLE OF CONTENTS  
- INSTALLATION SECTION -  
INSTALLATION SECTION ........................................ Section A  
Technical Specifications ...................................................A-1  
Safety Precautions ...........................................................A-2  
Select Proper Location.....................................................A-2  
Stacking.......................................................................A-2  
Tilting...........................................................................A-2  
Input Connections ............................................................A-2  
Fuse and Wire Sizes...................................................A-3  
Input Power Connections and Ground Connections...A-3  
Connect Shielding Gas................................................A-4  
Reconnect Procedure.......................................................A-5  
Connect Output Components...........................................A-7  
Install the Work Clamp................................................A-7  
Output Polarity Connection .........................................A-7  
Gun Liner and Contact Tip Installation........................A-7  
Wire Size Conversion Parts ........................................A-8  
Gun and Cable Installation..........................................A-8  
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A-1  
A-1  
INSTALLATION  
TECHNICAL SPECIFICATIONS - Wire-Matic-255  
INPUT - SINGLE PHASE/ 60 HERTZ ONLY  
Standard Voltage  
208/230/1/60  
Input Current at Rated Output  
53/49 Amps  
230/460/575  
50/25/20 Amps  
RATED OUTPUT  
Amps  
Duty Cycle  
Volts at Rated Amps  
100%  
60%  
35%  
145 amps  
200 amps  
26  
28  
26  
250 amps  
OUTPUT  
Current Range  
Maximum Open Circuit Voltage  
Wire Speed Range  
30A - 250A  
40V  
50 - 600 IPM  
(1.27-15.2 m./minute)  
RECOMMENDED INPUT WIRE & FUSE SIZE  
Input Voltage/  
Frequency  
Fuse (Superlag)  
or Breaker Size  
Type 750C wire in  
Copper conduit AWG  
(IEC Sizes)  
Type 750C Copper  
Ground Wire in Conduit  
Runs to  
Runs over  
100ft. (30m.) 100ft. (30m.)  
208/60  
230/60  
460/60  
575/60  
60  
60  
30  
25  
8 (10mm2) 6 (16mm2)  
10 (6mm2) 8 (10mm2)  
14 (2.5mm2) 12 (4mm2)  
14 (2.5mm2) 12 (4mm2)  
10 (6mm2)  
10 (6mm2)  
10 (6mm2)  
10 (6mm2)  
PHYSICAL DIMENSIONS  
HEIGHT  
Width  
DEPTH  
WEIGHT  
(W/GUN)  
28.2”  
18.8”  
40.1”  
220 lbs.  
(719mm)  
(480mm)  
(1019mm)  
(100 Kg.)  
OPERATING TEMPERATURE  
STORAGE  
OPERATING  
-200C to 400C  
± 400C  
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A-2  
A-2  
INSTALLATION  
Read entire Installation Section before installing  
the WIRE-MATIC 255  
INPUT CONNECTIONS  
WARNING  
SAFETY PRECAUTIONS  
All input power must be electrically  
disconnected before proceeding.  
WARNING  
ELECTRIC SHOCK can kill.  
• Only qualified personnel should  
install this machine.  
____________________________________  
1. Before starting the installation, check with the local  
power company to determine if there is any ques-  
tion about whether your power supply is adequate  
for the voltage, amperes, phase, and frequency  
specified on the welder nameplate. Be sure the  
planned installation will meet the U.S. National  
Electrical Code and local code requirements. This  
welder may be operated from a single phase line  
or from one phase of a two or three phase line.  
• Turn the input power OFF at the dis-  
connect switch or fuse box before  
working on the equipment.  
Do not touch electrically hot parts.  
Always connect the WIRE-MATIC 255 ground-  
ing terminal to a good electrical earth ground  
through the cable plug per the National  
Electrical Code.  
2. Models that have multiple input voltages specified  
on the nameplate (e.g., 208/230) are shipped con-  
nected for the highest voltage. If the welder is to  
be operated at a lower voltage, it must be recon-  
nected according to the instructions on the inside  
of the removable panel (Reconnect Access Door)  
near the top left side of the Case Back Assembly.  
See the Reconnect Section of this manual for  
details on reconnecting the machine to operate at  
different voltages.  
Set the Wire-Matic 255 ON/OFF Power switch to  
the OFF position when connecting power cord  
to input power.  
____________________________________  
SELECT PROPER LOCATION  
Place the WIRE-MATIC 255 where clean, cooling air  
can freely circulate in through the case back louvers  
and out through the case front louvers. Dirt, dust, or  
any foreign material that can be drawn into the  
machine case back louvers should be kept at a mini-  
mum. Not following these precautions can result in the  
nuisance shutdown of the machine because of exces-  
sive operating temperatures.  
3. Be sure the voltage, phase, and frequency of the  
input power is as specified on the machine rating  
plate. See Figure A.1 for the location of the  
machine's input cord entry, Reconnect Access  
Door, and Reconnect Panel, and Rear Nameplate.  
STACKING  
The WIRE-MATIC 255 cannot be stacked.  
TILTING  
The Wire-Matic 255 must be placed on a stable, level  
surface so it will not topple over. Do not place the  
machine on an incline.  
FIGURE A.1 - Case Back Assembly: Input Power  
Cable Entry Connections.  
WIRE-MATIC 255  
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A-3  
A-3  
INSTALLATION  
b. Fuse the two hot lines of the receptacle with  
super lag type fuses as shown in Figure A.2. A  
green wire in the input cord connects this ter-  
minal to the frame of the welder. This ensures  
proper grounding of the welder frame when the  
welder plug is inserted into the receptacle.  
FUSE AND WIRE SIZES  
Protect the input circuit with the super lag fuses or  
delay type circuit breakers listed on the Technical  
Specifications page of this manual for the machine  
being used. The tripping action of delay type circuit  
breakers decreases as the magnitude of the current  
increases. They are also called inverse time or ther-  
mal/magnetic circuit breakers.  
4. Use proper wire sizes. See the Technical  
Specification table for proper wire sizes. For  
cable lengths over 100 feet, larger copper wires  
should be used.  
DO NOT use fuses or circuit breakers with a lower amp  
rating than recommended. This can result in "nui-  
sance" tripping caused by inrush current even when  
machine is not being used for welding at high output  
currents.  
CAUTION  
Connect to a system grounding wire. See the  
United States National Electrical Code and local  
codes for other details and means for proper  
grounding.  
Use input and grounding wire sizes that meet local  
electrical codes or see the Technical Specifications  
page in this manual.  
Connect to hot wires of a three-wire, single phase  
system or to one phase of a two or three phase  
system.  
INPUT POWER CONNECTIONS AND  
GROUND CONNECTIONS  
Have a qualified electrician connect the receptacle or  
cable to the input power lines and the system ground  
according to the U.S. National Electrical Code and any  
applicable local codes.  
____________________________________  
1. Follow the Input Supply Connection Diagram on  
the inside of the Reconnect Panel Access Door.  
2. Use a single-phase line or one phase of a three-  
phase line.  
For the 208V/230V/ 60 HZ model WIRE-MATIC 255  
shipped with a 10 ft. input cord and plug connected to  
the welder, mount the matching receptacle supplied  
with the machine.  
1. Mount the receptacle in a suitable location using  
the screws provided.  
FIGURE A.2. - Ground Connections.  
2. Locate the receptacle within reach of the 10 ft.  
input cord attached to the welder.  
3. Mount the receptacle with the grounding terminal  
at the top. This allows the power cable to hang  
down without bending. See Figure A.2.  
a. The center terminal in the receptacle is for the  
grounding connection.  
WIRE-MATIC 255  
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A-4  
A-4  
INSTALLATION  
For the 230/460/575V/ 60 HZ model which is not  
equipped with a plug, an input cord, or a receptacle,  
the input power supply leads must be connected  
directly to the Reconnect Panel as shown in Figure  
A.3. Refer to Technical Specifications at the begin-  
ning of this chapter for proper wire sizes.  
WARNING  
Gas under pressure is explosive.  
Always keep gas cylinders in an  
upright position and always keep  
chained to undercarriage or sta-  
tionary Y support. See American  
National Standard Z-49.1, “Safety  
in Welding and Cutting” published by the American  
Welding Society.  
1. Strip 1/2" (13mm) of insulation from the input  
power supply leads.  
2. Connect the input power leads to terminals L1 and  
L2 on the Reconnect Panel Assembly.  
____________________________________  
3. Torque the terminal screws to 16 in.-lbs. (1.8nm).  
1. Set the gas cylinder on the rear platform of the  
WIRE-MATIC 255.  
2. Hook the chain in place to secure cylinder to rear  
of welder.  
3. Remove the cylinder cap.  
4. Inspect the cylinder valves for damaged threads,  
dirt, dust, oil or grease.  
a. Remove dust and dirt with a clean cloth.  
NOTE: DO NOT ATTACH THE REGULATOR IF OIL,  
GREASE OR DAMAGE IS PRESENT! Inform your  
gas supplier of this condition. Oil or grease in the pres-  
ence of high pressure oxygen is explosive.  
FIGURE A.3 - Input Power Connection For  
230/460/575 Volt Models.  
CONNECT SHIELDING GAS  
5. Stand to one side away from the outlet and open  
the cylinder valve for an instant to blow away any  
dust or dirt which may have accumulated in the  
valve outlet.  
Customer must provide cylinder of appropriate type of  
shielding gas for gas metal arc welding for the process  
being used. See Figure A.4 for the location of the com-  
ponents used to connect the air supply cylinder.  
BE SURE TO KEEP YOUR FACE AWAY FROM THE  
VALVE OUTLET WHEN OPENING THE VALVE.  
6. Inspect the regulator for damaged threads, dirt,  
dust, oil or grease.  
a. Remove dust and dirt with a clean cloth.  
NOTE: DO NOT USE THE REGULATOR IF OIL,  
GREASE OR DAMAGE IS PRESENT! Have an  
authorized repair station clean the regulator or repair  
any damage.  
WIRE-MATIC 255  
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A-5  
A-5  
INSTALLATION  
7. Attach the flow regulator to the cylinder valve and  
tighten the union nut(s) securely with a wrench.  
a. NOTE: If connecting the flow regulator to  
100% CO2 cylinder, insert the regulator  
adapter between the regulator and cylinder  
valve. If adapter is equipped with a plastic  
washer, be sure it is seated properly to con-  
nect to the CO2 cylinder.  
8. Connect one end of the inlet gas hose to the outlet  
fitting of the flow regulator.  
9. Connect the other end of the inlet gas hose to the  
WIRE-MATIC 255 rear fitting.  
10. Tighten both the union nuts securely with a  
wrench.  
11. Before opening the cylinder valve, turn the regula-  
tor adjusting knob counter-clockwise until the pres-  
sure is released from the adjusting spring.  
12. Open the cylinder valve slowly a fraction of a turn.  
a. When the cylinder pressure gage pointer stops  
moving, open the valve fully.  
FIGURE A.4 - Input Gas Supply Connections  
NEVER STAND DIRECTLY IN FRONT OF OR  
BEHIND THE FLOW REGULATOR WHEN OPENING  
THE CYLINDER VALVE. ALWAYS STAND TO ONE  
SIDE.  
RECONNECT PROCEDURE  
Multiple voltage machines are shipped connected to  
the highest input voltage listed on the machine's rating  
plate. Before installing the machine, check that the  
Reconnect Panel in the Input Box Assembly is con-  
nected for the proper voltage.  
13. The flow regulator is adjustable. Adjust the flow  
regulator for the flow rate recommended for the  
procedure and process being used before making  
the weld.  
CAUTION  
Failure to follow these instructions can cause  
immediate failure of components within the  
machine.  
___________________________________  
To reconnect a dual or triple voltage machine to a dif-  
ferent voltage, change the position of the leads or links  
on the Reconnect Panel based on the type of  
machine. Follow The Input Supply Connection  
Diagram located on the inside of the Case Back  
Reconnect Panel Access Door.  
For 208/230/1/60 machine(s), see Figure A.5.  
For 230/460/575/1/60 machine(s), see Figure A.6.  
WIRE-MATIC 255  
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A-6  
A-6  
INSTALLATION  
ALL MACHINES ARE SHIPPED FROM THE FACTORY CONNECTED FOR THE HIGHER OF THE TWO  
INPUT VOLTAGES LISTED ON THE NAMEPLATE. TO CHANGE VOLTAGE CONNECTION PROCEED AS  
FOLLOWS:  
1. REMOVE THE OUTER STEEL HEX NUT FROM THE TERMINAL WHERE THE TRANSFORMER  
INPUT LEAD IS CONNECTED.  
2. SHIFT THE TRANSFORMER INPUT LEAD TO THE TERMINAL THAT THE UNIT IS TO OPERATE  
ON AND FASTEN SECURELY WITH THE HEX NUT REMOVED IN STEP1. (MAKE CERTAIN THAT  
BRASS NUTS ARE TIGHT.)  
FIGURE A.5 - Reconnect Diagram For 208/230/1/60 Machines.  
1. ALL MACHINES ARE SHIPPED FROM THE FACTORY CONNECTED FOR THE HIGHEST NAME-  
PLATED SINGLE PHASE INPUT VOLTAGE. TO CHANGE CONNECTIONS FOR A DIFFERENT INPUT  
VOLTAGE, RECONNECT BOTH COPPER JUMPERS PER DIAGRAM BELOW. ALWAYS CONNECT  
JUMPERS BETWEEN OUTER STEEL NUT AND INNER BRASS NUT ON TERMINAL STUDS.  
2. CONNECT THE INPUT POWER TO THE INPUT TERMINAL BLOCK, L1 AND L2 AT THE UPPER COR-  
NER OF THE PANEL. TORQUE TO 16 IN-LBS.  
3. CONNECT A GROUNDING LEAD TO THE GROUND STUD ( ) ON THE MACHINE NEAR THE TER-  
MINAL BLOCK.  
FIGURE A.6 - Reconnect Diagram For 230/460/575/1/60 Machine.  
WIRE-MATIC 255  
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A-7  
A-7  
INSTALLATION  
GUN  
INSTALLATION  
LINER AND  
CONTACT  
TIP  
CONNECT OUTPUT COMPONENTS  
INSTALL THE WORK CLAMP  
The Magnum 250L gun and cable provided with the  
WIRE-MATIC 255 is factory installed with a liner for a  
.035-.045” (0.9-1.2mm) diameter electrode and an  
.035” (0.9mm) contact tip.  
Attach the work clamp to the cable which extends from  
the front of the machine using the following procedure:  
1. Insert the lug on the end of the work cable through  
the strain relief hole in the work clamp handle. See  
Figure A.7.  
1. If a .045” diameter wire size is to be used, install  
the .045” contact tip (also provided).  
2. For other wire sizes, use the following procedure  
for contact tip and gas nozzle installation. See  
Figure A.8.  
2. Slide the work cable through the hole up to the bolt  
and nut.  
3. Fasten work cable using the bolt and nut provided.  
a. Choose the correct size contact tip for the  
electrode being used (wire size is stenciled on  
the side of the contact tip) and screw it snugly  
into the gas diffuser.  
b
Be sure the nozzle insulator is fully screwed  
onto the gun tube and does not block the gas  
holes in the diffuser.  
c. Slip the appropriate gas nozzle onto the noz-  
zle insulator. Either a standard .50" (12.7mm)  
or optional .62” (15.9mm) I.D. slip-on gas noz-  
zle may be used and should be selected  
based on the welding application.  
d. Adjust the gas nozzle for the GMAW process  
to be used.  
FIGURE A.7 - Installing The Work Clamp.  
OUTPUT POLARITY CONNECTION  
WARNING  
For the short-circuiting transfer process, the contact tip  
end should be flush to extended to .12" (3.2mm). See  
Figure A.8.  
For the spray transfer process, the contact tip should  
be flush to recessed .12" (3.2mm). See Figure A.8.  
Turn the welder Power Switch OFF before chang-  
ing output connection.  
____________________________________  
The welder is shipped from the factory connected for  
electrode positive (+) polarity. This is the normal polar-  
ity for GMA welding.  
If negative (-) polarity is required, interchange the con-  
nection of the electrode and work cables at the output  
terminals located in the wire drive compartment near  
the front panel. The electrode cable, which is attached  
to the wire drive, is to be connected to the negative (-)  
labeled output terminal. The work cable which is  
attached to the work clamp is to be connected to the  
positive (+) labeled output terminal.  
FIGURE A.8  
Connections.  
-
Contact Tip and Electrode  
WIRE-MATIC 255  
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A-8  
A-8  
INSTALLATION  
WIRE SIZE CONVERSION PARTS  
The Wire-Matic 255 is rated to feed .025" through .045"  
(0.6-1.2mm) solid or cored electrode sizes. For vari-  
ous drive roll kits refer to Acessories Section.  
GUN AND CABLE INSTALLATION  
WARNING  
Turn the welder Power Switch OFF before chang-  
ing output connection.  
____________________________________  
1. Lay the cable out straight.  
2. Locate the knurled thumb screw on conductor  
block inside wire feed compartment. Unscrew it  
until the tip of the screw no longer protrudes into  
gun opening as seen from front of machine.  
3. Insert the brass connector on the end of the gun  
cable into conductor block through opening in the  
front panel. Make sure the connector is fully insert-  
ed and tighten thumb screw.  
4. Connect the gun trigger connector from the gun  
and cable to the mating receptacle on the front  
panel. Make sure that the keyways are aligned,  
insert and tighten retaining ring.  
NOTE: If a gun and cable other than the Magnum  
250L is used, it must conform to connector specifica-  
tions and the gun trigger switch must be capable of  
switching 5 milliamps at 15 volts DC -resistive.  
CAUTION  
The gun trigger switch connected to the gun trig-  
ger control cable must be a normally open,  
momentary switch. The terminals of the switch  
must be insulated from the Welding circuit.  
Improper operation of or damage to the WIRE-  
MATIC 255 might result if this switch is common to  
an electrical circuit other than the WIRE-MATIC 255  
trigger circuit.  
____________________________________  
WIRE-MATIC 255  
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NOTES  
WIRE-MATIC 255  
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OPERATION  
TABLE OF CONTENTS  
- OPERATION SECTION -  
OPERATION SECTION ............................................ Section B  
Safety Instructions............................................................B-1  
General Description..........................................................B-1  
Recommended Processes and Equipment......................B-2  
Design Features and Advantages....................................B-2  
Unit Features...............................................................B-2  
Power Source Features...............................................B-2  
Wire Feeder Features .................................................B-3  
Machine Capability...........................................................B-3  
Limitations ........................................................................B-3  
Controls and Settings.......................................................B-4  
Using the Wire Drive Roll.................................................B-5  
Procedure for Changing Drive Roll .............................B-5  
Loading the Wire Reel.................................................B-5  
Feeding Electrode .......................................................B-6  
Proper Wire Feeding ...................................................B-6  
Setting Idle Roll Pressure............................................B-7  
Operating Steps ...............................................................B-7  
Starting the Welder......................................................B-7  
Changing Run-In Mode ...............................................B-7  
Enter Slow Run-In Mode.........................................B-7  
Enter Fast Run-In Mode .........................................B-7  
Making a Weld.............................................................B-8  
WIRE-MATIC 255  
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B-1  
B-1  
OPERATION  
Read and understand this entire section before operat-  
ing your WIRE-MATIC 255.  
CAUTION  
When using a Wire-Matic 255 power source there  
will be a small spark if the electrode contacts the  
work or ground within several seconds after  
releasing the trigger.  
SAFETY INSTRUCTIONS  
WARNING  
____________________________________  
ELECTRIC SHOCK can kill.  
Do not touch electrically live  
parts such as output terminals  
or internal wiring.  
GENERAL DESCRIPTION  
The WIRE-MATIC 255 is a complete semiautomatic  
constant voltage DC arc welding machine built to meet  
NEMA specifications. It combines a constant voltage  
power source, a constant speed wire feeder, and a  
microcomputer-based controller to form a reliable high-  
performance welding system.  
Insulate yourself from the work  
and ground.  
Always wear dry insulating  
gloves.  
____________________________________  
Simple controls, consisting of continuous full range cal-  
ibrated voltage control and wire feed speed control,  
provide versatility with ease of use.  
FUMES AND GASES  
can be dangerous.  
Keep your head out of fumes.  
Use ventilation or exhaust to  
remove fumes from breathing  
zone.  
____________________________________  
WELDING, CUTTING and  
GOUGING SPARKS  
can cause fire or explosion  
Keep flammable material away.  
Do not weld, cut or gouge on  
containers that have held  
combustibles.  
____________________________________  
ARC RAYS  
can burn.  
Wear eye, ear and body  
protection.  
____________________________________  
Only qualified personnel should operate this equip-  
ment. Observe all safety information throughout this  
manual.  
WIRE-MATIC 255  
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B-2  
B-2  
OPERATION  
POWER SOURCE FEATURES:  
RECOMMENDED PROCESSES AND  
EQUIPMENT  
10 Ft. (3.0m) Input Power Cable - Includes plug and  
mating receptacle for 208/230V unit. Convenient rear  
reconnect panel allows easy access for 208V re-con-  
nection.  
The WIRE-MATIC 255 is recommended for GMA weld-  
ing processes using 10 to 44 lb. (4.5 to 20 kg) 2"  
(51mm) I.D. spools or Readi-Reel coils (with optional  
adapter) of:  
Power Switch - Front panel toggle switch turns input  
power on and off.  
.025" through .045" (0.6-1.2mm) solid steel.  
.035" (0.9mm) stainless steel.  
3/64" (1.2mm) aluminum.  
Pilot Light - Indicates when power is applied to  
machine.  
.045" (1.2mm) Outershield.  
.035" (0.9mm) and .045" (1.2mm) Innershield self-  
shielding electrodes.  
Thermostatically-Controlled Fans - Cools trans-  
former and other components only when required. The  
fan motors stays off when used intermittently or at low  
current procedures, reducing the amount of dust and  
dirt drawn into the machine. This also reduces power  
consumption.  
The WIRE-MATIC 255 is factory equipped to feed  
.035" (0.9mm) and .045" (1.2mm) electrodes. It  
includes a 12 ft. (3.6m) GMAW gun and cable assem-  
bly equipped for these wire sizes with a duty cycle rat-  
ing of 200A, 60% or 250A, 35%. Using GMAW  
processes requires use of the optional gas regulator  
and a supply of shielding gas.  
Electronic Overload Protection - Protects machine  
from short circuit or high current overloading.  
Power Source Line Voltage Regulation - Precise  
SCR phase control circuit holds the voltage setting at a  
constant level to maintain weld quality even when the  
input voltage fluctuates +/- 10%.  
DESIGN FEATURES AND  
ADVANTAGES  
UNIT FEATURES:  
Solid State Contactor -Output is turned on and off by  
SCR's instead of a mechanical contactor providing  
extra long life in highly repetitive welding applications.  
Continuous Voltage and Wire Speed Control -  
Large, easy to use control knobs provide continuous  
full-range calibrated control of both wire speed and  
voltage. A "ready-reference Procedure Chart” is pro-  
vided on the inside of the wire drive section door giving  
suggested settings for popular welding processes and  
plate thickness. Wire speed control has fine resolution  
calibrated dial for repeatable and precise setting.  
Output Terminals - Easily accessible in wire drive  
compartment for quick cable connection and polarity  
reversal.  
Work Cable - 10 ft. (3.0m) long with work clamp.  
Undercarriage for Hand Mobility - Heavy duty 10"  
(254mm) wheels and 4" (102mm) casters are factory  
installed. The handle can be used for storing the weld-  
ing gun and work cable.  
Adjustable Flow Regulator - Accomodates CO2 or  
argon blend gas. Includes a cylinder pressure gauge  
and a dual seal flow gauge.  
Gas cylinder Platform - Factory installed on the  
undercarriage, it permits platform mounting and sup-  
port of a single gas cylinder. It is not necessary to  
completely lift the gas cylinder when placing it on the  
platform.  
Easy Accessibility - The door on the wire feeder  
enclosure protects wire and wire drive from dirt, dust,  
and damage.  
WIRE-MATIC 255  
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B-3  
B-3  
OPERATION  
WIRE FEEDER FEATURES:  
MACHINE CAPABILITY  
Wire Loading - Adjustable brake spindle mounts  
Readi-Reel® Adapter, included with WIRE-MATIC 255,  
or most any 2" (51mm) I.D. wire spool.  
Accommodating standard 12" (305mm) and 8"  
(203mm) diameter coils, the spindle’s adjustable brake  
provides appropriate dereeling drag to prevent wire  
reel overrun and loop-offs.  
The WIRE-MATIC 255 is rated on the following duty  
cycles based on a 10-minute time period (i.e., for 60%  
duty cycle, it is 6 minutes on and 4 minutes off).  
Duty Cycle  
100%  
Amps.  
145  
Volts  
26  
60%  
200  
28  
Tachometer Controlled Wire Drive - Precision con-  
trol of permanent magnet motor provides proper wire  
feed acceleration and speed accuracy, independent of  
fluctuations in line voltage and wire loading. This gives  
reliable arc starting and weld consistency.  
35%  
250  
26  
Selectable Run-In Start-Up - A user selectable fea-  
ture allows the wire feeder to feed wire directly at the  
selected speed, (factory selected), or when the trigger  
is pulled the wire feeder feeds wire at slow speed  
regardless of the set wire feed speed until welding cur-  
rent is drawn or 2 seconds has expired. This feature  
enhances starting and makes setting stick out a snap  
The 2 second limit permits high speed loading of the  
gun and cable.  
LIMITATIONS  
The WIRE-MATIC 255 may not operate satisfactorily if  
powered with a portable or in-plant generating system.  
Solid State Overload Protection - No circuit breaker  
to reset. Simply pull the trigger to resume welding  
once the overload condition has been cleared.  
Unique Drive Roll and Guide Tube Design -  
Precisely aligned guide tubes and drive rolls provide  
long life. The design also permits quick reload by sim-  
ply starting wire into ingoing guide tube. Adjustable  
tension setting minimizes 'birdnesting', eliminates  
milling through the wire, and gives positive feeding.  
The double groove, reversible drive roll included with  
the WIRE-MATIC 255 allows use of .030" (0.8mm)  
through .045" (1.2mm) diameter wire. Drive roll kits for  
other sizes and types of wire are also available.  
Quick-Connect Welding Gun - Gun connector has  
integrated welding power and gas connection with sep-  
arate front-panel twist-lock trigger connection mount.  
Gun and Cable - A 12 ft. (3.6m) GMAW gun and cable  
assembly, rated 200 amps 60% duty, or 250 amps 35%  
duty, is provided with the WIRE-MATIC 255. A liner,  
diffuser and contact tips for .035" (0.9mm) and .045"  
(1.2mm) electrodes are included.  
WIRE-MATIC 255  
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B-4  
B-4  
OPERATION  
CONTROLS AND SETTINGS  
All operator controls are located on the Front  
Panel/Nameplate of the machine. See Figure B.1 for  
the location of each control.  
3
4
VOLTS  
WIRE SPEED  
2
LINCOLN  
WIRE-MATIC 255  
ELECTRIC  
ON  
1
0
WARNING  
OFF  
POWER  
1
Figure B.1 - Operator Controls.  
inches per minute (1.2 to 15.2 m/min). The control  
can be preset on the dial to the setting specified on  
the Procedure Decal on the inside of the wire com-  
partment door. Wire speed is not affected when  
changes are made in the voltage control.  
1. POWER SWITCH: Toggle switch to turn input  
power ON and OFF. Place the lever in the ON  
position to turn the WIRE-MATIC 255 ON.  
2. PILOT LIGHT: The red LED pilot light located next  
to the POWER SWITCH is lit when the power is  
ON.  
NOTE: When the trigger is pulled, the wire feeder  
feeds wire at low speed regardless of the wire feed  
speed set on the control until the welding arc starts or  
2 seconds has elapsed. This feature enhances start-  
ing and makes it easier to set the stickout. The 2 sec-  
ond limit permits high speed loading of the gun and  
cable.  
3. VOLTAGE CONTROL POTENTIOMETER KNOB:  
Provide continuous adjustment of power source  
output voltage over the rated 12 to 28 volt range.  
Voltage can be adjusted while welding.  
4. WIRE SPEED CONTROL POTENTIOMETER  
KNOB: Controls the wire speed from 50 to 600  
WIRE-MATIC 255  
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B-5  
B-5  
OPERATION  
USING THE WIRE DRIVE ROLL  
MOULDED ADAPTER  
RETAINING SPRING  
The drive roll provided with the WIRE-MATIC 255 has  
two grooves, one for.030-.035" (0.8-0.9mm) solid steel  
electrode, and the other for .045" (1.2mm) solid steel  
electrode. The welder is shipped with the drive roll  
installed in the .030-.035" (0.8-0.9mm) position as indi-  
cated by the stenciling on the exposed side of the drive  
roll. If .045" (1.2mm) electrode is to be used or one of  
the optional drive rolls is required, then the drive roll  
must be reversed or changed per the following instruc-  
tions. This information also appears on the Procedure  
Decal on the door inside the wire compartment.  
WIRE DEREELING  
DIRECTION  
2" (51 mm)  
O.D. SPINDLE  
LOCKING COLLAR  
BRAKE TENSION  
ADJUSTING SCREW  
READI-REEL  
PROCEDURE FOR CHANGING DRIVE  
ROLL  
INSIDE CAGE WIRES  
Different wire sizes may require changing the drive roll.  
The applicable wire sizes are stamped on the drive roll.  
Dual groove rolls must be installed so the side with the  
proper wire size stamp faces out.  
FIGURE B.2 - Wire Reel Loading.  
4. Set one of the Readi-Reel inside cage wires on the  
slot in the retaining spring tab.  
1. Turn POWER SWITCH to OFF.  
5. Lower the Readi-Reel to depress the retaining  
spring and align the other inside cage wires with  
the grooves in the molded adapter.  
2. Release the pressure on the idle roll by swinging  
the pressure arm off the idle roll arm.  
6. Slide the cage all the way onto the adapter until the  
retaining spring "pops" up fully.  
3. Remove the wire from the drive system.  
4. Remove the thumb screw from the drive roll.  
WARNING  
5. Turn the drive roll over or change to another roll as  
required.  
Check to be sure the retaining spring has fully  
returned to the locking position and has securely  
locked the Readi-reel cage in place. Retaining  
spring must rest on the cage not the welding elec-  
trode.  
6. Replace the thumb screw.  
7. Check that the gun liner and contact tip are prop-  
erly sized for wire being used.  
____________________________________  
LOADING THE WIRE REEL  
NOTE: The retaining spring side of the Adapter should  
be facing the center (inner) panel of the WIRE-MATIC  
255.  
To mount a 22-30 lb. (10-14 kg) Readi-Reel package  
using the Readi-Reel adapter provided:  
7. To remove the Readi-Reel from Adapter, depress  
retaining spring tab with thumb while pulling the  
Readi-Reel cage from the molded adapter with  
both hands. Do not remove Adapter from spindle.  
1. Remove the locking collar from the 2” (51mm) O.D.  
spindle and mount the K363P Adapter so the spin-  
dle pin engages the hole provided in the Adapter.  
Replace and tighten the locking collar.  
2. Rotate the spindle and adapter so the retaining  
spring is at the 12 o'clock position.  
3. Position the Readi-Reel so that it will rotate in a  
clockwise direction when wire is dereeled from the  
top of the coil. See Figure B.2.  
WIRE-MATIC 255  
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B-6  
B-6  
OPERATION  
To mount a 10 to 44 lb. (4.5 to 20 kg) spools: 8”  
(200mm) [Use K468 Adapter] and 12” (300mm)  
diameter:  
5. Press the gun trigger and push the electrode into  
the drive roll.  
a. If the electrode fails to thread itself into the out-  
going guide tube of the wire drive  
1. Remove the locking collar and the Readi-Reel  
Adapter (if installed) on the 2 inch (51mm) diame-  
ter spindle.  
open the quick release idle roll arm  
thread the electrode manually  
re-close the arm.  
2. If using an 8” (200mm) spool, place the K468  
Adapter on the spindle first. The hole in the  
Adapter arm is to engage the pin on the spindle.  
3. Place the spool on the spindle, making certain the  
brake driving pin enters one of the holes in the  
back side of the spool. Be certain the wire comes  
off the reel in a clockwise direction when dereeled  
from the top of the coil.  
6. Inch the electrode through the gun.  
NOTE: If using the low speed starting feature, the wire  
will feed at low speed for 2 seconds while inching, then  
come up to the set speed. To change run-in mode, see  
the Changing the Run In Mode Section.  
4. Replace and tighten the locking collar for several  
seconds.  
PROPER WIRE FEEDING  
FEEDING ELECTRODE  
Wire feeding problems can be avoided by observing  
the following gun handling procedures:  
Do not kink or pull cable around sharp corners.  
WARNING  
When inching, the electrode and drive mechanism  
are electrically hot to work and ground. The elec-  
trode remains hot several seconds after the gun  
trigger is released.  
Keep the electrode cable as straight as possible  
when welding or loading electrode through cable.  
Do not allow dolly wheels or trucks to run over  
cables.  
____________________________________  
Keep cable clean by following maintenance  
instructions.  
NOTE: Check that the proper drive rolls and gun parts  
for the wire size and type are being used.  
Use only clean, rust-free electrode. The Lincoln  
electrodes have proper surface lubrication.  
1. Turn the Readi-Reel or spool until the free end of  
the electrode is accessible.  
Replace contact tip when the arc starts to become  
unstable or the contact tip end is fused or  
deformed.  
2. Tightly holding the electrode, cut off the bent end  
and straighten the first six inches.  
a. If the electrode is not properly straightened, it  
may not feed properly into the outgoing guide  
tube or welding gun causing a "birdnest.")  
3. Cut off the first inch.  
4. Push the wire through the ingoing guide tube.  
WIRE-MATIC 255  
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B-7  
B-7  
OPERATION  
NOTE: When the POWER SWITCH is ON, the fan  
motor is thermostatically controlled to provide cooling  
for the transformer and other components only when  
the machine needs cooling. When the machine does  
not require fan cooling the fan does not run, such as  
when first turned on, when welding at low current, or at  
low duty cycle procedures.  
SETTING IDLE ROLL PRESSURE  
The idle roll pressure thumb screw is set at the factory  
backed out 2-1/2 turns from full pressure. This is an  
approximate setting. The optimum idle roll pressure  
varies with type of wire, wire diameter, surface condi-  
tions, lubrication, and hardness. As a general rule,  
hard wires may require greater pressure, and soft, or  
aluminum wire, may require less pressure than the fac-  
tory setting. The optimum idle roll setting can be deter-  
mined as follows:  
CHANGING RUN-IN MODE  
1. Push the end of gun against a solid object that is  
electrically isolated from the welder output.  
FAST OR SLOW RUN-IN MODE  
SELECTION  
2. Press the gun trigger for several seconds.  
The WIRE-MATIC 255 is factory set for fast run-in  
mode where the wire feed will accelerate directly to the  
preset wire feed speed when the gun trigger is closed.  
a. If the wire "birdnests", jams, or breaks at the  
drive roll, the idle roll pressure is too great.  
Back the thumb screw out 1/2 turn, run new  
wire through gun, and repeat steps 1 and 2.  
Slow run-in mode may also be selected, where it will  
initially feed wire at 50 IPM until output current is  
sensed or for 2.0 seconds, whichever occurs first.  
After which it will accelerate to the preset wire feed  
speed.  
b. If the drive roll slips, loosen the thumb screw  
on the conductor block and pull the gun cable  
forward about 6" (15 cm). There should be a  
slight waviness in the exposed wire. If there is  
no waviness, the pressure is too low. Tighten  
the thumb screw 1/4 turn, reinstall the gun  
cable, and repeat steps 1 and 2.  
INSTRUCTIONS TO ENTER SLOW RUN-IN  
MODE  
1. Turn power OFF on front panel of Wire-Matic 255.  
2. Turn the wire feed speed dial to minimum, fully  
counterclockwise.  
OPERATING STEPS  
3. With the gun trigger closed, turn the power ON at  
the front panel of the Wire-Matic 255.  
WARNING  
Before operating the machine, be sure you have all  
the materials needed to perform the work. Be sure  
you are familiar with and have taken all possible  
safety precautions before starting the work. It is  
important that you follow these operating steps  
each time you use the machine.  
4. The gas solenoid will actuate two times to signal  
that the unit has entered the slow run-in mode (the  
gun trigger need only be closed until the first gas  
solenoid actuation is heard).  
INSTRUCTIONS TO ENTER FAST RUN-IN  
MODE  
___________________________________  
STARTING THE WELDER  
1. Turn power OFF on front panel of Wire-Matic 255.  
1. Turn the POWER switch to ON. This illuminates  
the red LED pilot light.  
2. Turn the wire feed speed dial to maximum, fully  
clockwise.  
2. Select the correct voltage and wire speed for the  
welding process required.  
3. With the gun trigger closed, turn the power ON at  
the front panel of the Wire-Matic 255.  
3. Operate the gun trigger for welder output and to  
energize the wire feeder motor.  
4. The gas solenoid will actuate four times to signal  
that the unit has entered the fast run-in mode (the  
gun trigger need only be closed until the first gas  
solenoid actuation is heard).  
WIRE-MATIC 255  
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B-8  
B-8  
OPERATION  
NOTE: Arc starting characteristics may be affected  
when using the fast run-in mode since optimum start-  
ing processes are being overriden.  
NOTE: When using Innershield electrode, the gas  
nozzle may be removed from the insulation on the end  
of the gun. This will give improved visibility and elimi-  
nate the possibility of the gas nozzle overheating.  
When the trigger is closed at power up, no output  
power or wire feed will be available until the trigger is  
opened and reclosed, regardless of wire feed speed  
dial setting.  
7. Connect the work cable to metal to be welded.  
Work clamp (if used) must make good electrical  
contact to the work. The work must be grounded.  
It is not necessary to repeat either of the above proce-  
dures each time the unit is powered up. The unit will  
remember the run-in mode from the previous power  
down and return you to that same state upon your next  
power up. Thus, you need only perform one of the  
above procedures when you want to change the run-in  
mode.  
WARNING  
When using an open arc process, it is necessary to  
use correct eye, head and body protection.  
____________________________________  
8. Position electrode over joint. End of electrode may  
be lightly touching the work.  
MAKING A WELD  
1. Check that the electrode polarity is correct for the  
process being used.  
9. Lower welding helmet, close gun trigger, and begin  
welding. Hold the gun so the contact tip to work  
distance is about 3/8 inch (10mm) or 3/4" (20mm)  
for Outershield.  
2. Turn the POWER SWITCH to ON.  
3. Set desired arc voltage and wire speed for the  
electrode wire, material type and thickness, and  
gas (for GMAW) being used.  
10. To stop welding, release the gun trigger and then  
pull the gun away from the work after the arc goes  
out.  
NOTE: Use the Application Chart on the door inside  
the wire compartment as a quick reference for some  
common welding procedures.  
11. When no more welding is to be done, close the  
valve on gas cylinder (if used), momentarily oper-  
ate gun trigger to release gas pressure.  
NOTE: If Timer Kit is installed, see the Accessories  
Section of this manual to select the desired mode and  
for additional welding information Spot and Stitch  
modes.  
12. Turn POWER SWITCH to OFF.  
4. Inch the electrode through the gun and cable.  
5. Cut the electrode within approximately 3/8"  
(10mm) of the end of the contact tip or 3/4" (20mm)  
for Outershields.  
NOTE: If set to slow run-in, when the trigger is pulled  
the wire feeder feeds wire at low speed regardless of  
the set wire feed speed until the welding arc starts or 2  
seconds has elapsed. This feature enhances starting  
and makes it easier to set the stickout. The 2 second  
limit permits high speed loading of the gun and cable.  
To change run-in mode, refer to Changing Run In  
Mode Section.  
6. If welding gas is to be used, turn on the gas supply  
and set the required flow rate (typically 25-35 CFH;  
12-16 Liters/min).  
WIRE-MATIC 255  
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NOTES  
WIRE-MATIC 255  
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ACCESSORIES  
TABLE OF CONTENTS  
- ACCESSORIES SECTION -  
ACCESSORIES SECTION ....................................... Section C  
Other Available Magnum 250L Gun and  
Cable Assembly ..........................................................C-1  
Magnum Gun Connection Kit (Optional K466-6) .............C-1  
K672-1 Spool Gun Adapter Kit.........................................C-1  
Making a Weld with the Spool Gun Adapter and  
Spool Gun (K672-1) Installed......................................C-1  
Making a Weld with the Spool Gun Adapter (K672-1)  
Installed.......................................................................C-2  
Timer Kit (K585-1)............................................................C-3  
Timer Kit Installation (Optional K585-1)...........................C-3  
Making Spot and Stitch Welds with Timer Kit Installed ...C-4  
Drive Roll Kits ..................................................................C-4  
3/64” Aluminum Feeding Kit (K673-1)..............................C-4  
K468 8” Spool Adapter.....................................................C-4  
K363P Readi-Reel Adapter..............................................C-4  
Dual Cylinder Mounting (K671-1).....................................C-5  
WIRE-MATIC 255  
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C-1  
C-1  
ACCESSORIES  
The kit includes a spool gun adapter module assembly  
with a single connecting plug, a rear gas inlet setting  
with hose, a gun and cable holders and mounting  
hardware with installation and operating instructions.  
(L9696)  
OPTIONS/ACCESSORIES  
OTHER AVAILABLE MAGNUM 250L  
GUN AND CABLE ASSEMBLY  
The following GMAW gun and cable assemblies are  
available for use with the WIRE-MATIC 255. Each is  
rated 200 amps 60% duty cycle or 250 amps 35% duty  
cycle. The gun and cable assemblies are equipped  
with the integrated connector, twist-lock trigger con-  
nector, and includes a liner, diffuser, and contact tips  
for the wire sizes specified:  
CAUTION  
The spool gun module is intended for use with  
Lincoln Electric® Magnum™ Spool Guns only. Use  
with other units may cause damage to the equip-  
ment. For Spool Gun operation, refer to the  
instruction manual provided with the Magnum™  
Spool Gun.  
LENGTH  
PART NO.  
WIRE SIZE  
____________________________________  
10' (3.0 m)  
12' (3.6 m)  
15’ (4.5 m)  
K533-1  
K533-2*  
K533-3  
.035-.045”  
(0.9-1.2mm)  
MAKING A WELD WITH THE SPOOL  
GUN ADAPTER AND SPOOL GUN  
(K672-1) INSTALLED  
10' (3.0 m)  
12' (3.6 m)  
15’ (4.5 m)  
K533-4  
K533-5  
K533-6  
.025-.030”  
(0.6-0.8mm)  
The toggle switch on the front of the spool gun adapter  
box permits quick transfer between the use of the  
Wire-Matic 255 with its feeder gun and the connected  
spool gun for same polarity electrodes.  
* Included with the K578-1.  
MAGNUM GUN CONNECTION KIT  
(Optional K466-6)  
Using the optional K466-6 Magnum Connection kit for  
the Wire-Matic permits use of standard Magnum 200,  
300 or 400 gun and cable assemblies.  
K672-1 SPOOL GUN ADAPTER KIT  
WARNING  
Remove all input power to the Wire-Matic 255  
before proceeding.  
____________________________________  
The K672-1 Spool Gun Adapter Kit provides recessed  
panel “up front" direct connection of the K487 Spool  
Gun (with remote speed control), or the K469 Spool  
Gun (requiring K518 Connection Adapter) with the SP-  
255, SP255-I and Wire-Matic 255 wire feed welder  
machines.  
It also provides single switch transfer between the  
machine's use with its feeder gun or the spool gun for  
same polarity welding with different wire and gas  
processes.  
WIRE-MATIC 255  
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C-2  
C-2  
ACCESSORIES  
NOTE: The WIRE-MATIC 255 speed calibrated dial  
markings are not accurate when used for setting the  
Spool Gun speed.  
MAKING A WELD WITH THE SPOOL  
GUN ADAPTER (K672-1) INSTALLED  
4. The following procedure settings can be used as  
initial settings for making test welds to determine  
final settings:  
CAUTION  
In either transfer switch position, closing the gun  
trigger will cause the electrode of both guns to be  
electrically "HOT." Be sure unused gun is posi-  
tioned so the electrode or the tip will not contact  
metal case or other metal common to the work. A  
gun holder is provided with the K672-1 kit for this  
purpose.  
Wire Diameter  
In. (mm)  
WFS Setting  
Wire-Matic 255  
Arc Voltage  
Setting  
.030” (.8mm)  
.035” (.9mm)  
3/64” (1.2mm)  
270  
250  
210  
15 V  
16 V  
21 V  
____________________________________  
5. To return to normal WIRE-MATIC 255 welding, set  
the transfer switch to FEEDER position and reset  
feeder gun weld procedure settings.  
1. The transfer switch in FEEDER position:  
a. Disables spool gun trigger, wire feed, and gas  
output.  
b. Closing the feeder gun trigger starts feeder  
gun welding and makes both electrodes elec-  
trically "HOT."  
2. Transfer switch in SPOOL position:  
a. Disables feeder gun wire feed and gas output.  
However, closing feeder gun trigger will make  
both electrodes electrically “HOT” and activate  
spool gun gas output.  
b. Closing spool gun trigger starts spool gun  
welding and makes both electrodes electrical-  
ly "HOT".  
3. Operation with Wire-Matic 255:  
a. Turn the Wire-Matic input power ON, and the  
transfer switch is to be in the SPOOL position.  
b. Adjusting the voltage control will increase or  
decrease your welding Voltage.  
c. Adjusting the wire speed control will increase  
or decrease the spool gun wire feed speed.  
This represents the set speed for the K469  
spool gun and the maximum set speed for the  
K487 Spool Gun with the remote control in gun  
handle at maximum.  
The remote control turned to minimum will give  
approximately 50% of the maximum set WFS.  
WIRE-MATIC 255  
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C-3  
C-3  
ACCESSORIES  
TIMER KIT (K585-1)  
TIMER KIT INSTALLATION  
(OPTIONAL K585-1)  
The Timer Kit provides selectable 4-step trigger inter-  
lock, spot and stitch functions, and manual adjustment  
of burnback time. This kit installs easily using only a  
screwdriver. It replaces the blank upper panel on Case  
Front. It offers the following mode selections:  
WARNING  
Remove all input power to the WIRE-MATIC 255  
before proceeding.  
The Normal Welding mode provides welding  
power only while gun trigger is pressed.  
____________________________________  
1. Verify that the following items have been included  
in the kit:  
The 4-Step Trigger mode eliminates the need to  
hold gun trigger while welding. It operates in 4  
steps:  
a. Timer Board and Panel Assembly.  
b. Two sheet metal screws.  
1. Close trigger and establish welding arc.  
2. Release trigger and continue welding.  
3. Re-close trigger near end of weld.  
4. Release trigger again to stop welding.  
c. Wiring harness.  
2. Turn the POWER SWITCH to OFF.  
3. Disconnect AC input power to the machine.  
The Spot Weld mode allows a single timed weld  
cycle each time the gun trigger is held closed.  
Duration is set with SPOT/STITCH ON TIME knob.  
4. Remove the Cover Plate Assembly from the front  
of the machine by removing the two screws which  
fasten it using a screwdriver, a 5/16" (8mm) nut dri-  
ver, or other suitable tool.  
The Stitch Weld mode allows repeated timed weld  
cycles while gun trigger is held closed. Weld on-  
time is set with SPOT/STITCH ON TIME knob, and  
weld off time is set with STITCH OFF TIME knob.  
5. Reach through the exposed panel opening and  
attach the rectangular 8-pin plug connector on the  
Timer Kit wiring harness to the available mating  
receptacle connector on the upper left corner of  
the Control Board inside the machine.  
The BURNBACK TIME knob is used to manually set  
arc power delay at the end of any above selected weld  
mode to prevent wire sticking in the weld. With the  
Timer Kit not installed, a preselected delay is automat-  
ically set by the machine.  
a. Be sure that the latch on the connector is  
aligned with that on the Control Board and  
insert it until the latch engages.  
b. Check that the remaining connector on the  
opposite end of the wiring harness is firmly  
attached to the mating connector on the PC  
Board on the Timer Kit panel, and that the  
latch is engaged.  
6. Align the Timer Kit panel so you can carefully insert  
the printed circuit board and wiring harness  
through the opening in the front panel.  
a. Make sure the wiring harness is not pinched  
between panels or between printed circuit  
board and front panel.  
7. Fasten the Timer Kit assembly with either the two  
supplied screws or with the original screws to com-  
plete the installation.  
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C-4  
C-4  
ACCESSORIES  
3. Set the procedure for the metal thickness to be  
welded.  
MAKING SPOT AND STITCH WELDS  
WITH TIMER KIT INSTALLED  
4. Close trigger and hold it closed for length of seam.  
TO MAKE SPOT PLUG WELDS:  
a. Hold gun in one place during ON time and  
move gun just beyond edge of molten metal  
during OFF time.  
The SPOT WELD MODE is used to make spot plug  
welds when continuous welds are not needed or to  
hold thin sheet metal together prior to stitch welding or  
continuous welding.  
NOTE: For smoothest welds on thinner metal, point  
gun slightly toward the direction of travel.  
Plug welds are made by using a punch to make a 3/16"  
(5mm) diameter hole in the top sheet and arc welding  
through the hole into the back sheet.  
DRIVE ROLL KITS  
1. Punch 3/16" (5mm) holes in the top sheet.  
The following drive rolls and Magnum 250L gun and  
cable parts are available to feed different sizes and  
types of electrodes.  
2. Set the SPOT/STITCH ON-TIME control to  
approximately 1.2 seconds.  
Steel Wire Sizes:  
.025 - .035" (0.6-0.9mm)  
.030 - .045" (0.8-1.2mm)  
.045" Cored (1.2mm)  
Part Number  
KP674-035S  
KP674-045S  
KP674-045C  
3. Set the procedure for the metal thickness to be  
welded.  
4. Install spot weld nozzle (if available) on gun and  
press it against the top sheet so the top and bot-  
tom sheets are tight together.  
Aluminum Wire Sizes:  
3/64" (1.2mm)  
KP674-3/64A  
5. Close trigger and hold it closed until the arc goes  
out.  
3/64” (1.2mm) ALUMINUM FEEDING  
KIT (K673-1)  
a. If a spot weld nozzle is not used, smoother  
welds will result by moving the welding wire in  
a small circle during the weld.  
Provides gun and wire drive conversion parts to weld  
with 3/64” (1.2mm) aluminum wire. 5356 alloy alu-  
minum wire is recommended for best push feeding  
performance.  
TO MAKE A STITCH WELD:  
The STITCH WELD MODE is used to weld thin mater-  
ial when warpage and burn through are a problem.  
Proper adjustment of the Spot/Stitch On-Time, Stitch  
Off-Time, and arc travel speed permits welding thin  
sheet metal with small welds, minimum distortion, and  
no burnthrough.  
Kit includes drive roll and incoming guide tube for the  
wire drive, and 450 gun tube, liner and two contact tips  
for the gun, along with S21529 installation instructions.  
1. The SPOT/STITCH ON-TIME KNOB sets welding  
time.  
K468 8” SPOOL ADAPTER  
The K468 Spool Adapter permits the use of 8” Spools  
on the Wire-Matic 255 spindle.  
a. Start with a dial setting of 0.5 seconds. Raise  
setting to increase penetration and weld size.  
Lower setting to reduce burnthrough and dis-  
tortion.  
K363P READI-REEL ADAPTER  
2. The STITCH OFF-TIME KNOB sets off time  
between welds.  
The K363P Readi-Reel Adapter mounts to the 2” spin-  
dle. It is needed to mount the 22-20 lb. Readi-Reels.  
a. Start with a dial setting of 0.5 seconds. Raise  
setting to reduce burnthrough. Lower setting  
to make weld flatter and smoother.  
WIRE-MATIC 255  
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C-5  
C-5  
ACCESSORIES  
DUAL CYLINDER MOUNTING KIT  
(K671-1)  
Permits stable side-by-side mounting of two full size  
(9” dia. x 5’ high) gas cylinders with “no lift” loading.  
Simple installation with installation kick stand and easy  
instructions provided (L9687). Includes upper and  
lower cylinder supports, wheel axles and mounting  
hardware.  
WIRE-MATIC 255  
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MAINTENANCE  
TABLE OF CONTENTS  
- MAINTENANCE SECTION -  
MAINTENANCE SECTION ...................................... Section D  
Safety Precautions...........................................................D-1  
Routine and Periodic Maintenance..................................D-1  
Component Locations ......................................................D-2  
Drive Rolls and Guide Tubes...........................................D-3  
Cable Cleaning.................................................................D-3  
Gun Tubes and Nozzles...................................................D-3  
Contact Tip and Gas Nozzle Installation..........................D-3  
Liner Removal and Replacement.....................................D-4  
Liner Removal, Installation, and Trimming Instructions  
for Magnum 250L........................................................D-4  
Gun Handle Disassembly ................................................D-5  
Accessories and Expendable Replacement Parts for  
Magnum 250L Gun and Cable Assemblies .....................D-6  
WIRE-MATIC 255  
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D-1  
D-1  
MAINTENANCE  
SAFETY PRECAUTIONS  
WARNING  
Have a qualified electrician do the maintenance  
and troubleshooting work.  
Disconnect the input power off using the dis-  
connect switch at the main input supply before  
working inside machine.  
Unplug the power cable if it is connected to a  
receptacle.  
____________________________________  
Read the Safety Precautions in the front of this manu-  
al before working on this machine.  
ROUTINE AND PERIODIC  
MAINTENANCE  
1. Disconnect input AC power supply lines to the  
machine before performing periodic maintenance,  
tightening, cleaning, or replacing parts. See  
Figure D.1.  
Perform the following daily:  
1. Check that no combustible materials are in the  
welding or cutting area or around the machine.  
2. Remove any debris, dust, dirt, or materials that  
could block the air flow to the machine.  
3. Inspect the electrode cables for any slits, punc-  
tures in the cable jacket, or any condition that  
would affect the proper operation of the machine.  
Perform Periodically:  
Clean the inside of the machine with low pressure air  
stream. Clean the following parts. Refer to Figure D.1.  
Main transformer and choke.  
Electrode and work cable connections.  
SCR rectifier bridge and heat sink fins.  
Fan Motor Assembly.  
Control Printed Circuit Board.  
NOTE: The fan motor has sealed bearings which  
require no maintenance.  
WIRE-MATIC 255  
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D-2  
D-2  
MAINTENANCE  
CONTROL PC  
BOARD  
FAN MOTORS  
SCR RECTIFIER  
BRIDGE  
CHOKE  
MAIN TRANSFORMER  
Figure D.1 - Component Locations.  
WIRE-MATIC 255  
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D-3  
D-3  
MAINTENANCE  
DRIVE ROLLS AND GUIDE TUBES  
CONTACT TIP AND GAS NOZZLE  
INSTALLATION  
After every coil of wire, inspect the wire drive mecha-  
nism. Clean it as necessary by blowing with low pres-  
sure compressed air. Do not use solvents for cleaning  
the idle roll because it may wash the lubricant out of  
the bearing. All drive rolls are stamped with the wire  
sizes they will feed. If a wire size other than that  
stamped on the roll is used, the drive roll must be  
changed.  
1. Choose the correct size contact tip for the elec-  
trode being used (wire size is stenciled on the side  
of the contact tip) and screw it snugly into the gas  
diffuser.  
a. Be sure the nozzle insulator is fully screwed  
onto the gun tube and does not block the gas  
holes in the diffuser.  
CABLE CLEANING  
2. Slip or screw the appropriate gas nozzle onto the  
nozzle insulator.  
Clean the cable liner after using approximately 300  
pounds (136 kg) of electrode.  
Note: Either a standard .50" (12.7mm) or optional .62"  
(15.9mm) I.D. slip-on gas nozzle may be used and  
should be selected based on the welding application.  
1. Remove the cable from the wire feeder and lay it  
out straight on the floor.  
3. Adjust the gas nozzle as appropriate for the  
GMAW process to be used.  
2. Remove the contact tip from the gun.  
3. With an air hose at the gas diffuser end, use low  
pressure to gently blow out the cable liner.  
a. Typically, the contact tip end should be flush to  
extended .12" (3.2mm) for the short-circuiting  
transfer process and recessed .12" (3.2mm)  
for spray transfer.  
CAUTION  
Excessive pressure at the start may cause the dirt  
to form a plug.  
____________________________________  
4. Flex the cable over its entire length and again blow  
out the cable.  
5. Repeat this procedure until no more dirt comes  
out.  
GUN TUBES AND NOZZLES  
1. Replace worn contact tips as required.  
2. Remove spatter from the inside of the gas nozzle  
and tip every 10 minutes of arc time or as required.  
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D-4  
D-4  
MAINTENANCE  
LINER REMOVAL AND  
REPLACEMENT  
NOTE: When you change wire size, a replacement  
gas diffuser is required. Use the table below to select  
the proper diffuser so the liner is held securely in place.  
Diameter of  
Electrodes Used  
Replacement Liner  
Part Number  
Size Stenciled on  
End of Liner  
Bushing  
Fixed Nozzle Gas  
Diffuser Part No.  
(and Stencil)  
Adjustable Nozzle  
Gas Diffuser Part  
No. (and Stencil)  
.025-.030" Steel  
(0.6-0.8mm)  
M16087-2  
M16087-1  
M17714-1  
.030 (0.8mm)  
.045 (1.2mm)  
3/64” (1.2mm)  
S19418-3  
S19418-3  
S19418-3  
S19418-2  
S19418-1  
S19418-1  
.035-.045" Steel  
(0.9-1.2mm)  
3/64" Aluminum  
(1.2mm)  
8. Fully seat the liner bushing into the connector.  
9. Tighten the setscrew on the brass cable connector.  
LINER REMOVAL, INSTALLATION,  
AND TRIMMING INSTRUCTIONS  
FOR MAGNUM 250L  
NOTE: Do not install the gas diffuser onto the end of  
the gun tube at this time.  
NOTE: The variation in cable lengths prevents the  
interchange ability of liners between guns. Once a liner  
has been cut for a particular gun, it should not be  
installed in another gun unless it can meet the liner cut  
off length requirement. Liners are shipped with the  
jacket of the liner extended the proper amount.  
10. Straighten the cable with the gas nozzle and noz-  
zle insulator removed from the gun tube.  
11. Trim the liner to the length shown in FIGURE D.2.  
1. Remove the gas nozzle and nozzle insulator.  
SET SCREW  
BRASS CABLE CONNECTOR  
2. Locate the set screw in the gas diffuser which is  
used to hold the old liner in place.  
1-1/4" (1.25)  
(31.8MM)  
LINER TRIM  
LENGTH  
3. Loosen the set screw with a 5/64" (2.0mm) Allen  
wrench.  
4. Remove the gas diffuser from the gun tube.  
5. Lay the gun and cable out straight on a flat sur-  
face.  
6. Loosen the set screw located in the brass connec-  
tor at the feeder end of the cable and pull the liner  
out of the cable.  
GAS DIFFUSER  
NOZZLE INSULATOR  
7. Insert a new untrimmed liner into the connector  
end of the cable.  
GAS NOZZLE  
a. Check the liner bushing stencil to make sure it  
is the appropriate one for the wire size being  
used.  
FIGURE D.2 - Liner maintenance.  
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D-5  
D-5  
MAINTENANCE  
12 Remove any burrs from the end of the liner.  
13. Screw the gas diffuser onto the end of the gun tube  
and tighten.  
NOTE: Be sure the gas diffuser is correct for the liner  
being used. (See table and diffuser stencil.)  
COUNTER-  
14. Slightly tighten the set screw in the side of the gas  
diffuser against the cable liner using 5/64" (2.0mm)  
Allen wrench.  
CLOCKWISE  
CAUTION  
This screw should only be gently tightened. Over  
tightening will split or collapse the liner and cause  
poor wire feeding.  
____________________________________  
FIGURE D.3 - Gun Handle disassembly.  
GUN HANDLE DISASSEMBLY  
The internal parts of the gun handle may be inspected  
or serviced if necessary.  
The gun handle consists of two halves that are held  
together with a collar on each end.  
To open up the handle:  
1. Turn the collars approximately 60 degrees coun-  
terclockwise (the same direction as removing a  
right hand thread) until the collar reaches a stop.  
2. Pull the collar off the gun handle.  
NOTE: If the collars are difficult to turn, position the  
gun handle against a corner, place a screwdriver  
against the tab on the collar and give the screwdriver a  
sharp blow to turn the collar past an internal locking rib.  
See Figure D.3.  
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D-6  
D-6  
MAINTENANCE  
ACCESSORIES AND EXPENDABLE  
REPLACEMENT PARTS FOR  
MAGNUM 250L GUN AND CABLE  
ASSEMBLIES  
DESCRIPTION  
PART NO.  
ENGLISH SIZE  
METRIC SIZE  
Cable Liner  
For 15' (4.5m) or Shorter Cable  
M16087-2  
M16087-1  
M17714-1*  
.025- .030"  
.035- .045"  
3/64" (Alum. Wire)  
0.6 - 0.8 mm  
0.9 - 1.2 mm  
1.2 mm (Alum. Wire)  
Contact Tips  
S19391-6  
S19391-7  
S19391-1**  
S19391-2**  
.025"  
.030"  
.035"  
.045"  
0.6 mm  
0.8 mm  
0.9 mm  
1.2 mm  
Standard Duty  
Heavy Duty  
S19392-1  
S19292-2  
.035"  
.045"  
0.9 mm  
1.2 mm  
S19393-5  
S19393-6  
S19393-1  
S19393-2  
.025"  
.030"  
.035"  
.045"  
0.6 mm  
0.8 mm  
0.9 mm  
1.2 mm  
Tapered  
Tab (For Aluminum)  
S18697-46*  
3/64” (Alum. wire)  
1.2 mm  
Gas Nozzles  
Fixed (Flush)  
M16081-1  
M16081-2**  
M16081-3  
3/8”  
1/2”  
5/8”  
9.5 mm  
12.1 mm  
15.9 mm  
(Recessed)  
M16080-1  
M16080-2  
M16080-3  
3/8”  
5/8”  
5/8”  
9.5 mm  
15.9 mm  
15.9 mm  
(Requires: Gas Diffuser Assembly.)  
Adjustable Slip-On  
S19418-3  
.025-.045”  
0.6-1.2 mm  
M16093-2  
M16093-1  
1/2”  
5/8”  
12.7 mm  
15.9 mm  
(Requires: Nozzle Insulator Assembly.)  
(Requires: Gas Diffuser Assembly)  
S19417-1  
S19416-2  
S19416-2  
0.25 - .030"  
0.35 - .045"  
0.6-0.8 mm  
0.9-1.2mm  
Gasless Nozzle (for Innershield®)  
M16938***  
Gun Tube Assembly  
Standard (60 Degrees)  
45 Degrees  
S18920**  
S19890*  
*
Included with K673-1 3/64” (1.2 mm) Aluminum  
Feeding Kit. 5356 alloy aluminum wire recom-  
mended to alleviate potential soft wire feeding  
problems with push-type wire feeding.  
** Included with Wire-Matic 255.  
*** Requires S19428-1 Gas Diffuser Assembly.  
WIRE-MATIC 255  
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NOTES  
WIRE-MATIC 255  
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THEORY OF OPERATION  
TABLE OF CONTENTS  
- THEORY OF OPERATION SECTION -  
THEORY OF OPERATION SECTION ...................... Section E  
Power Supply Operation .................................................E-1  
Input Line Voltage and Main Transformer...................E-1  
Output Rectification and Feedback Control ................E-2  
Constant Voltage Output .............................................E-3  
Wire Drive Motor and Feedback .................................E-4  
Thermal Protection...........................................................E-5  
SCR Operation.................................................................E-6  
WIRE  
SPEED  
GAS  
SOLENOID  
WIRE  
DRIVE  
MOTOR  
ARC  
VOLTAGE  
CONTROL BOARD  
TACH  
G
A
T
GUN TRIGGER AND THUMB SWITCH  
FEEDBACK  
E
MAIN  
TRANSFORMER  
LINE  
SWITCH  
S
I
G
N
A
L
RECONNECT  
POSITIVE  
TERMINAL  
CHOKE  
C
A
P
A
C
I
T
O
R
S
F
E
E
D
B
A
C
K
SCR  
RECTIFIER  
FAN  
NEGATIVE  
TERMINAL  
MOTORS  
SHUNT  
Figure E.1 -Block Logic Diagram  
NOTE: Unshaded areas of Block Logic  
Diagram are the subject of discussion  
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E-1  
E-1  
THEORY OF OPERATION  
INPUT LINE VOLTAGE AND MAIN TRANSFORMER  
WIRE  
SPEED  
GAS  
SOLENOID  
WIRE  
DRIVE  
MOTOR  
ARC  
VOLTAGE  
CONTROL BOARD  
TACH  
G
A
T
GUN TRIGGER AND THUMB SWITCH  
FEEDBACK  
E
MAIN  
TRANSFORMER  
LINE  
SWITCH  
S
I
G
N
A
L
RECONNECT  
POSITIVE  
TERMINAL  
CHOKE  
C
A
P
A
C
I
T
O
R
S
F
E
E
D
B
A
C
K
SCR  
RECTIFIER  
NEGATIVE  
TERMINAL  
FAN  
MOTORS  
SHUNT  
Figure E.2 - Input Line Voltage and Main Transformer.  
INPUT LINE VOLTAGE AND MAIN  
TRANSFORMER  
The desired single phase input power is connected to  
the WIRE-MATIC 255 through a line switch located on  
the front panel.  
A reconnect panel allows the user to configure the  
machine for the desired input voltage. This AC input  
voltage is applied to the primary of the main trans-  
former and to the thermostatically controlled fan  
motors. The transformer changes the high voltage, low  
current input power to a low voltage, high current out-  
put. In addition, the main transformer also has an iso-  
lated center tapped 30 VAC auxiliary winding that sup-  
plies power to the Control Board for SCR gate drive  
and gas solenoid operation. The weld power windings  
connect to the Control Board as well as to the main  
SCR Rectifier.  
NOTE: Unshaded areas of Block Logic  
Diagram are the subject of discussion  
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E-2  
E-2  
THEORY OF OPERATION  
OUTPUT RECTIFICATION AND FEEDBACK  
WIRE  
SPEED  
GAS  
SOLENOID  
WIRE  
DRIVE  
MOTOR  
ARC  
VOLTAGE  
CONTROL BOARD  
TACH  
G
A
T
GUN TRIGGER AND THUMB SWITCH  
FEEDBACK  
E
MAIN  
TRANSFORMER  
LINE  
SWITCH  
S
I
G
N
A
L
RECONNECT  
POSITIVE  
TERMINAL  
CHOKE  
C
A
P
A
C
I
T
O
R
S
F
E
E
D
B
A
C
K
SCR  
RECTIFIER  
NEGATIVE  
TERMINAL  
FAN  
MOTORS  
SHUNT  
Figure E.3 - Output Rectification and Feedback.  
OUTPUT RECTIFICATION AND  
FEEDBACK CONTROL  
The AC output from the main transformer secondary  
weld winding is rectified and controlled through the  
SCR rectifier assembly. Output voltage and current  
are sensed at the shunt and output terminals and are  
fed back to the control board. The control board com-  
pares the commands of the ARC Voltage Control  
potentiometer with the feedback signals. The appro-  
priate gate firing pulses are generated by the control  
board and applied to the SCR rectifier assembly. The  
control board controls the firing of the SCRs, thus con-  
trolling the output of the machine.  
See SCR  
Operation. The control board also powers and com-  
mands the gas solenoid and the wire drive motor.  
NOTE: Unshaded areas of Block Logic  
Diagram are the subject of discussion  
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E-3  
E-3  
THEORY OF OPERATION  
CONSTANT VOLTAGE OUTPUT  
WIRE  
SPEED  
GAS  
SOLENOID  
WIRE  
DRIVE  
MOTOR  
ARC  
VOLTAGE  
CONTROL BOARD  
TACH  
G
A
T
GUN TRIGGER AND THUMB SWITCH  
FEEDBACK  
E
MAIN  
TRANSFORMER  
LINE  
SWITCH  
S
I
G
N
A
L
RECONNECT  
POSITIVE  
TERMINAL  
CHOKE  
C
A
P
A
C
I
T
O
R
S
F
E
E
D
B
A
C
K
SCR  
RECTIFIER  
NEGATIVE  
TERMINAL  
FAN  
MOTORS  
SHUNT  
Figure E.4 - Constant Voltage Output.  
CONSTANT VOLTAGE OUTPUT  
The controlled DC output from the SCR rectifier  
assembly is filtered by the capacitor bank resulting is a  
constant voltage DC output. Since the output choke is  
in series with the positive leg of the rectifier and also in  
series with the gun and welding load, a filtered con-  
stant voltage output is applied to the output terminals  
of the machine.  
NOTE: Unshaded areas of Block Logic  
Diagram are the subject of discussion  
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E-4  
E-4  
THEORY OF OPERATION  
WIRE DRIVE MOTOR AND FEEDBACK  
WIRE  
SPEED  
GAS  
SOLENOID  
WIRE  
DRIVE  
MOTOR  
ARC  
VOLTAGE  
CONTROL BOARD  
TACH  
G
A
T
GUN TRIGGER AND THUMB SWITCH  
FEEDBACK  
E
MAIN  
TRANSFORMER  
LINE  
SWITCH  
S
I
G
N
A
L
RECONNECT  
POSITIVE  
TERMINAL  
CHOKE  
C
A
P
A
C
I
T
O
R
S
F
E
E
D
B
A
C
K
SCR  
RECTIFIER  
NEGATIVE  
TERMINAL  
FAN  
MOTORS  
SHUNT  
Figure E.5 - Wire Drive Motor and Feedback.  
WIRE DRIVE MOTOR AND  
FEEDBACK  
The wire drive motor is controlled by the control board.  
A motor speed feedback signal is generated at the  
motor tach and sent to the control board. The control  
board compares this feedback signal with the com-  
mands set forth by the Wire Speed Control poten-  
tiometer and sends the appropriate armature voltage  
to the wire drive motor. The drive motor speed is thus  
controlled which in turn regulates the electrode wire  
feed speed through the gun.  
NOTE: Unshaded areas of Block Logic  
Diagram are the subject of discussion  
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E-5  
E-5  
THEORY OF OPERATION  
THERMAL PROTECTION  
THERMAL PROTECTION  
A thermostat protects the machine from excessive  
operating temperatures. Excessive operating temper-  
atures may be caused by a lack of cooling air or oper-  
ating the machine beyond the duty cycle and output  
rating. There are three thermostats within the WIRE-  
MATIC 255 machine. One of the thermostats, located  
on the output choke, energizes the cooling fan motors  
when required. The other choke thermostat "opens"  
the trigger circuit, preventing machine weld output and  
wire feed, if excessive operating temperatures are  
detected. The third thermostat insures that the fan  
motors are operating when required.  
The thermostats are self-resetting once the machine  
cools sufficiently. If the thermostat shutdown is caused  
by excessive output or duty cycle and the fans are  
operating normally, the power switch may be left on  
and the reset should occur within a 15 minute period.  
If the fans are not turning or the air intake louvers are  
obstructed, then the input power must be removed and  
the fan problem or air obstruction be corrected.  
NOTE: Unshaded areas of Block Logic  
Diagram are the subject of discussion  
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E-6  
E-6  
THEORY OF OPERATION  
SCR OPERATION  
INPUT  
CATHODE  
OUTPUT  
NOTE: AS THE GATE  
PULSE IS APPLIED  
LATER IN THE CYCLE  
THE SCR OUTPUT  
IS DECREASED.  
ANODE  
GATE  
Figure E.6 - SCR Operation  
A silicon controlled rectifier (SCR) is a three terminal  
device used to control rather large currents to a load.  
An SCR acts very much like a switch. When a gate sig-  
nal is applied to the SCR it is turned ON and there is  
current flow from anode to cathode. In the ON state the  
SCR acts like a closed switch. When the SCR is turned  
OFF there is no current flow from anode to cathode  
thus the device acts like an open switch. As the name  
suggests, the SCR is a rectifier, so it passes current  
only during positive half cycles of the AC supply. The  
positive half cycle is the portion of the sine wave in  
which the anode of the SCR is more positive than the  
cathode.  
An SCR is fired by a short burst of current into the gate.  
This gate pulse must be more positive than the cath-  
ode voltage. Since there is a standard PN junction  
between gate and cathode, the voltage between these  
terminals must be slightly greater than 0.6V. Once the  
SCR has fired it is not necessary to continue the flow  
of gate current. As long as current continues to flow  
from anode to cathode the SCR will remain on. When  
the anode to cathode current drops below a minimum  
value, called holding current, the SCR will shut off. This  
normally occurs as the AC supply voltage passes  
through zero into the negative portion of the sine wave.  
If the SCR is turned on early in the positive half cycle,  
the conduction time is longer resulting in greater SCR  
output. If the gate firing occurs later in the cycle the  
conduction time is less resulting in lower SCR output.  
When an AC supply voltage is applied to the SCR, the  
device spends a certain portion of the AC cycle time in  
the off state and the remainder of the time in the on  
state. The amount of time spent in the ON state is con-  
trolled by the gate.  
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NOTES  
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TROUBLESHOOTING & REPAIR  
TABLE OF CONTENTS  
- TROUBLESHOOTING & REPAIR SECTION -  
TROUBLESHOOTING & REPAIR SECTION ........................................................................ Section F  
How to use Troubleshooting Guide....................................................................................................F-1  
PC Board Troubleshooting Procedures..............................................................................................F-2  
Troubleshooting Guide .......................................................................................................................F-3  
Test Procedures  
Main Transformer Test................................................................................................................F-10  
Static SCR Rectifier Bridge Test.................................................................................................F-13  
Active SCR Rectifier Assembly Test...........................................................................................F-16  
Wire Drive Motor and Tachometer Feedback Test.....................................................................F-19  
Oscilloscope Waveforms..................................................................................................................F-22  
Normal Open Circuit Voltage Waveform ....................................................................................F-22  
Typical Output Voltage Waveform - Machine Loaded................................................................F-23  
Abnormal Output Voltage Waveform - Machine Loaded One Output SCR Not Functioning.....F-24  
Abnormal Open Circuit Voltage Output Capacitor Bank Not Functioning..................................F-25  
Typical SCR Gate Voltage Waveform ........................................................................................F-26  
Replacement Procedures  
Control PC Board Removal and Replacement...........................................................................F-27  
Wire Drive Assembly Removal and Replacement......................................................................F-29  
SCR Output Rectifier Removal and Replacement .....................................................................F-31  
Capacitor Bank Removal and Replacement ..............................................................................F-33  
Main Transformer Removal and Replacement...........................................................................F-35  
Fan Motor and Fan Removal and Replacement........................................................................F-37  
Retest After Repair.....................................................................................................................F-40  
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F-1  
F-1  
TROUBLESHOOTING & REPAIR  
HOW TO USE TROUBLESHOOTING GUIDE  
WARNING  
Service and Repair should only be performed by Lincoln Electric Factory Trained Personnel.  
Unauthorized repairs performed on this equipment may result in danger to the technician and  
machine operator and will invalidate your factory warranty. For your safety and to avoid  
Electrical Shock, please observe all safety notes and precautions detailed throughout this  
manual.  
__________________________________________________________________________  
This Troubleshooting Guide is provided to  
help you locate and repair possible machine  
malfunctions. Simply follow the three-step  
procedure listed below.  
Step 3. RECOMMENDED COURSE OF  
ACTION  
The last column labeled “Recommended  
Course of Action” lists the most likely com-  
ponents that may have failed in your  
machine. It also specifies the appropriate  
test procedure to verify that the subject com-  
ponent is either good or bad. If there are a  
number of possible components, check the  
components in the order listed to eliminate  
one possibility at a time until you locate the  
cause of your problem.  
Step 1. LOCATE PROBLEM (SYMPTOM).  
Look under the column labeled “PROBLEM  
(SYMPTOMS)”. This column describes pos-  
sible symptoms that the machine may exhib-  
it. Find the listing that best describes the  
symptom that the machine is exhibiting.  
Symptoms are grouped into the following  
categories: output problems, function prob-  
lems, wire feeding problems, and welding  
problems.  
All of the referenced test procedures  
referred to in the Troubleshooting Guide are  
described in detail at the end of this chapter.  
Refer to the Troubleshooting and Repair  
Table of Contents to locate each specific  
Test Procedure. All of the specified test  
points, components, terminal strips, etc. can  
be found on the referenced electrical wiring  
diagrams and schematics. Refer to the  
Electrical Diagrams Section Table of  
Contents to locate the appropriate diagram.  
Step 2. PERFORM EXTERNAL TESTS.  
The second column labeled “POSSIBLE  
AREAS OF MISADJUSTMENT(S)” lists the  
obvious external possibilities that may con-  
tribute to the machine symptom. Perform  
these tests/checks in the order listed. In  
general, these tests can be conducted with-  
out removing the case wrap-around cover.  
CAUTION  
If for any reason you do not understand the test procedures or are unable to perform the  
tests/repairs safely, contact the Lincoln Electric Service Department for technical trou-  
bleshooting assistance before you proceed call 216-383-2531 or 1-800-833-9353.  
_____________________________________________________________  
WIRE-MATIC 255  
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F-2  
F-2  
TROUBLESHOOTING & REPAIR  
PC BOARD TROUBLESHOOTING PROCEDURES  
- Remove the P.C. Board from the static-  
shielding bag and place it directly into the  
equipment. Don’t set the P.C. Board on or  
near paper, plastic or cloth which could have a  
static charge. If the P.C. Board can’t be  
installed immediately, put it back in the static-  
shielding bag.  
WARNING  
ELECTRIC SHOCK can kill.  
Have an electrician install  
and service this equipment.  
Turn the input power OFF at  
the fuse box before work-  
ing on equipment. Do not  
touch electrically hot parts.  
- If the P.C. Board uses protective shorting  
jumpers, don’t remove them until installation is  
complete.  
_______________________________  
CAUTION:  
Sometimes machine failures  
- If you return a P.C. Board to The Lincoln  
Electric Company for credit, it must be in the  
static-shielding bag. This will prevent further  
damage and allow proper failure analysis.  
appear to be due to PC board failures. These  
problems can sometimes be traced to poor  
electrical connections. To avoid problems  
when troubleshooting and replacing PC  
boards, please use the following procedure:  
4. Test the machine to determine if the failure  
symptom has been corrected by the  
replacement PC board.  
1. Determine to the best of your technical abil-  
ity that the PC board is the most likely com-  
ponent causing the failure symptom.  
NOTE: It is desirable to have a spare (known  
good) PC board available for PC board trou-  
bleshooting.  
2. Check for loose connections at the PC  
board to assure that the PC board is proper-  
ly connected.  
NOTE: Allow the machine to heat up so that  
all electrical components can reach their oper-  
ating temperature.  
3. If the problem persists, replace the suspect  
PC board using standard practices to avoid  
static electrical damage and electrical  
shock. Read the warning inside the static  
resistant bag and perform the following pro-  
cedures:  
5. Remove the replacement PC board and  
substitute it with the original PC board to  
recreate the original problem.  
a. If the original problem does not reappear  
by substituting the original board, then  
the PC board was not the problem.  
Continue to look for bad connections in  
the control wiring harness, junction  
blocks, and terminal strips.  
P.C. Board can be dam-  
aged by static electricity.  
- Remove your body’s static  
charge before opening the  
static-shielding bag. Wear  
an anti-static wrist strap. For  
safety, use a 1 Meg ohm  
resistive cord connected to  
a grounded part of the  
equipment frame.  
ATTENTION  
Static-Sensitive  
Devices  
Handle only at  
Static-Safe  
Workstations  
b. If the original problem is recreated by the  
substitution of the original board, then  
the PC board was the problem. Reinstall  
the replacement PC board and test the  
machine.  
Reusable  
Container  
- If you don’t have a wrist  
6. Always indicate that this procedure was fol-  
lowed when warranty reports are to be sub-  
mitted.  
Do Not Destroy strap, touch an unpainted,  
grounded, part of the equip-  
ment frame. Keep touching the frame to pre-  
vent static build-up. Be sure not to touch any  
electrically live parts at the same time.  
NOTE: Following this procedure and writing  
on the warranty report, “INSTALLED AND  
SWITCHED PC BOARDS TO VERIFY PROB-  
LEM,” will help avoid denial of legitimate PC  
board warranty claims.  
- Tools which come in contact with the P.C.  
Board must be either conductive, anti-static or  
static-dissipative.  
WIRE-MATIC 255  
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F-3  
F-3  
TROUBLESHOOTING & REPAIR  
TROUBLESHOOTING GUIDE - Observe all Safety Guidelines detailed throughout this manual  
PROBLEMS  
(SYMPTOMS)  
POSSIBLE AREAS OF  
MISADJUSTMENTS(S)  
RECOMMENDED  
COURSE OF ACTION  
OUTPUT PROBLEMS  
1. Contact The Lincoln Electric  
Service Dept. (216) 383-2531 or  
1-800-833-9353 (WELD)  
Major Physical or Electrical Damage 1. Contact your local Lincoln  
is Evident Electric Authorized Field  
Service Facility.  
1. Check input power switch (S1).  
It may be faulty.  
Machine is dead- No Open Circuit 1. Make certain that the input  
Voltage output and No Wire Feed  
when gun trigger is pulled.  
power switch is in the "ON" posi-  
tion.  
2. Check for lose or broken wires  
at the reconnect panel.  
2. Check the input voltage at the  
machine. Input voltage must  
match the rating plate and the  
reconnect panel.  
3. Perform Main Transformer  
Test.  
4. Check the thermostats and  
associated leads for loose or  
broken connections. See wiring  
diagram.  
3. Blown or missing fuses in the  
input line.  
4. The thermostats may be open  
due to machine overheating. If  
machine operates normally after  
a cooling off period then check  
for proper fan operation and  
ventilation. Make certain that  
the machine's duty cycle is not  
being exceeded.  
5. The control board may be faulty.  
Replace.  
5. Check the trigger circuit. Leads  
#324 to #325 should have conti-  
nuity (zero ohms) when the gun  
trigger is pulled. If not then the  
gun may be faulty - replace.  
CAUTION  
If for any reason you do not understand the test procedures or are unable to perform the tests/repairs safely, con-  
tact the Lincoln Electric Service Department for technical troubleshooting assistance before you proceed call 216-  
383-2531 or 1-800-833-9353  
WIRE-MATIC 255  
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F-4  
F-4  
TROUBLESHOOTING & REPAIR  
TROUBLESHOOTING GUIDE - Observe all Safety Guidelines detailed throughout this manual  
PROBLEMS  
(SYMPTOMS)  
POSSIBLE AREAS OF  
MISADJUSTMENTS(S)  
RECOMMENDED  
COURSE OF ACTION  
OUTPUT PROBLEMS  
1. Check for loose or broken con-  
nections at the output terminals,  
the choke, the capacitor bank  
and all heavy current carrying  
leads.  
No Open Circuit Voltage output but 1. Check the input voltage at the  
wire feeds normally when gun trig-  
ger is pulled.  
machine. Input voltage must  
match the rating plate and the  
reconnect panel.  
2. The gun may be faulty. Check  
or replace.  
2. Make sure that the transformer  
secondary leads are securely  
connected to the SCR Rectifier  
Assembly.  
3. Perform the SCR Rectifier  
Assembly Test.  
4. The control board may be faulty  
- Replace.  
1. Check for loose or faulty con-  
nections of the heavy current  
carrying leads.  
Wire feeds but welding output is low 1. Make sure that the proper wire  
causing wire to "stub". Welds are  
"cold". Machine cannot obtain full  
and procedures are being used.  
rated output of 200 amps at 28 volts. 2. Check gun and work cable for  
loose or faulty connections.  
2. The output capacitor bank may  
be faulty. Check for loose con-  
nections at the capacitors. Also  
check for leaky capacitors.  
Replace if necessary.  
WARNING: The liquid elec-  
trolyte in these capacitors is  
toxic. Avoid contact with any  
portion of your body.  
3. Perform the SCR Rectifier  
Assembly Test.  
4. Perform the Main Transformer  
Test.  
5. The control board may be faulty.  
Replace.  
CAUTION  
If for any reason you do not understand the test procedures or are unable to perform the tests/repairs safely, con-  
tact the Lincoln Electric Service Department for technical troubleshooting assistance before you proceed call 216-  
383-2531 or 1-800-833-9353  
WIRE-MATIC 255  
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F-5  
F-5  
TROUBLESHOOTING & REPAIR  
TROUBLESHOOTING GUIDE - Observe all Safety Guidelines detailed throughout this manual  
PROBLEMS  
(SYMPTOMS)  
POSSIBLE AREAS OF  
MISADJUSTMENTS(S)  
RECOMMENDED  
COURSE OF ACTION  
OUTPUT PROBLEMS  
1. Check the machine's internal  
trigger leads for grounds or  
shorts. See Wiring Diagram.  
The output voltage and wire feed is 1. Remove the gun. If the problem  
present continuously or pulsing  
when gun trigger is NOT activated.  
is resolved the gun trigger circuit  
is faulty. Repair or replace.  
2. The control board may be faulty.  
Replace.  
2. If the problem is not resolved  
then contact your Local Lincoln  
Electric  
Authorized  
Field  
Service Facility.  
CAUTION  
If for any reason you do not understand the test procedures or are unable to perform the tests/repairs safely, con-  
tact the Lincoln Electric Service Department for technical troubleshooting assistance before you proceed call 216-  
383-2531 or 1-800-833-9353  
WIRE-MATIC 255  
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F-6  
F-6  
TROUBLESHOOTING & REPAIR  
TROUBLESHOOTING GUIDE - Observe all Safety Guidelines detailed throughout this manual  
PROBLEMS  
(SYMPTOMS)  
POSSIBLE AREAS OF  
MISADJUSTMENTS(S)  
RECOMMENDED  
COURSE OF ACTION  
FUNCTION PROBLEMS  
1. The Arc Voltage Control poten-  
tiometer may be faulty. Check or  
replace. See Wiring Diagram.  
No control of arc voltage. Wire feed- 1. The Arc Voltage Control poten-  
ing is normal.  
tiometer may be dirty. Rotate  
several times and check if prob-  
lem is resolved.  
2. Perform the SCR Rectifier  
Assembly Test.  
3. The control board may be faulty.  
Replace.  
1. Check the gas solenoid by dis-  
connecting it from the control  
board (Plug J8) and applying a  
12 VDC external supply to the  
gas solenoid. If the solenoid  
does NOT activate then it may  
be faulty. Replace.  
There is no gas flow when gun trig- 1. Check gas source and hoses for  
ger is pulled. Wire feeds and weld  
voltage is present.  
leaks or kinks.  
2. If Spool Gun adaptor is not  
installed make certain jumper  
plug is installed in plug J20. See  
Wiring Diagram.  
2. The control broad may be faulty.  
Replace.  
1. Check the motor armature cur-  
rent. Normal armature current is  
1.75 amps maximum. If the  
motor armature current is normal  
the control board may be faulty.  
Replace.  
The machine stops feeding wire 1. Check for mechanical restric-  
while welding.  
tions in the wire feeding path.  
The gun may be clogged.  
2. If the motor armature current is  
high (2 to 2.5 amps) and there  
are NO restrictions in the wire  
feeding path then the motor or  
gear box may be defective.  
Replace.  
CAUTION  
If for any reason you do not understand the test procedures or are unable to perform the tests/repairs safely, con-  
tact the Lincoln Electric Service Department for technical troubleshooting assistance before you proceed call 216-  
383-2531 or 1-800-833-9353  
WIRE-MATIC 255  
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F-7  
F-7  
TROUBLESHOOTING & REPAIR  
TROUBLESHOOTING GUIDE - Observe all Safety Guidelines detailed throughout this manual  
PROBLEMS  
(SYMPTOMS)  
POSSIBLE AREAS OF  
MISADJUSTMENTS(S)  
RECOMMENDED  
COURSE OF ACTION  
WIRE FEEDING PROBLEMS  
1. The Wire Speed Control poten-  
tiometer may be faulty. Check  
No control of wire feed speed. 1. The wire feed speed control  
Other machine functions are nor-  
mal.  
may be dirty. Rotate several  
times and check if problem is  
resolved.  
or replace.  
Diagram.  
See Wiring  
2. Perform the Wire Drive Motor  
and Tach Feedback test.  
3. The control board may be faulty.  
Replace.  
1. If the drive rolls are turning then  
check for a mechanical restric-  
tion in the wire feed path.  
1. Perform the Wire Drive Motor  
There is no wire feed when gun trig-  
ger is pulled. Normal open circuit  
voltage is present.  
and Tach Feedback Test.  
2. The Wire Feed Control poten-  
tiometer may be faulty. Check  
2. The gun liner may be clogged.  
Check or Replace.  
or replace.  
Diagram.  
See Wiring  
3. If the drive rolls are NOT turning  
when the gun trigger is pulled  
then contact your local Lincoln  
3. The control board may be faulty.  
Replace.  
Field  
Electric  
Authorized  
Service Facility.  
CAUTION  
If for any reason you do not understand the test procedures or are unable to perform the tests/repairs safely, con-  
tact the Lincoln Electric Service Department for technical troubleshooting assistance before you proceed call 216-  
383-2531 or 1-800-833-9353  
WIRE-MATIC 255  
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F-8  
F-8  
TROUBLESHOOTING & REPAIR  
TROUBLESHOOTING GUIDE - Observe all Safety Guidelines detailed throughout this manual  
PROBLEMS  
(SYMPTOMS)  
POSSIBLE AREAS OF  
MISADJUSTMENTS(S)  
RECOMMENDED  
COURSE OF ACTION  
WELDING PROBLEMS  
1. Check for loose connections at  
the output terminals, the choke,  
the capacitor bank and all heavy  
current carrying leads.  
The arc is unstable and or "hunting". 1. Check for worn or melted con-  
tact tip.  
2. Check for loose or faulty con-  
nections on the work and elec-  
trode cables.  
2. Make sure that the transformer  
secondary leads are securely  
connected to the SCR Rectifier  
Assembly.  
3. Make sure electrode polarity is  
correct or welding process  
being used.  
3. The output capacitor bank may  
be faulty. Check for loose con-  
nections at the capacitors. Also  
check for leaky capacitors.  
Replace if necessary.  
4. Check for rusty or dirty wire.  
5. Make sure machine settings  
and gas are correct for process  
being used.  
WARNING: The liquid elec-  
trolyte in these capacitors is  
toxic. Avoid contact with any  
portion of your body.  
4. The control board may be faulty.  
Replace  
1. The output capacitor bank may  
be faulty. Check for loose con-  
nections at the capacitors. Also  
check for leaky capacitors.  
Replace if necessary.  
Weld bead is narrow or ropy. May 1. Make sure the weld procedure  
have porosity with electrode stub-  
bing into plate.  
and electrode polarity is correct  
for the process being used.  
2. Make sure shielding gas is cor-  
rect and flow is proper.  
WARNING: The liquid elec-  
trolyte in these capacitors is  
toxic. Avoid contact with any  
portion of your body.  
3. Make sure the weld joint is not  
"contaminated".  
2. The control board may be faulty.  
Replace.  
The contact tip seizes in the gas dif- 1. The tip being over heated due to  
fuser.  
excessive current and/or high  
duty cycle welding.  
2. A light application of high tem-  
perature antisieze lubricant  
(such as Lincoln E2607  
Graphite Grease) may be  
applied to the contact tip  
threads.  
CAUTION  
If for any reason you do not understand the test procedures or are unable to perform the tests/repairs safely, con-  
tact the Lincoln Electric Service Department for technical troubleshooting assistance before you proceed call 216-  
383-2531 or 1-800-833-9353  
WIRE-MATIC 255  
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F-9  
F-9  
TROUBLESHOOTING & REPAIR  
TROUBLESHOOTING GUIDE - Observe all Safety Guidelines detailed throughout this manual  
PROBLEMS  
(SYMPTOMS)  
POSSIBLE AREAS OF  
MISADJUSTMENTS(S)  
RECOMMENDED  
COURSE OF ACTION  
WELDING PROBLEMS  
1. Perform the Output Rectifier  
The welding arc is variable and slug- 1. Check the welding cable con-  
Bridge Test.  
gish.  
nections for loose or faulty con-  
nections.  
2. The control board may be faulty.  
Replace.  
2. Make sure the wire feed speed,  
voltage, and shielding gas are  
correct for the process being  
used.  
1. The control board may be faulty.  
Replace.  
The arc striking is poor.  
1. Check the welding cable con-  
nections for loose or faulty con-  
nections.  
2. Make sure the wire feed speed,  
voltage, and shielding gas are  
correct for the process being  
used.  
CAUTION  
If for any reason you do not understand the test procedures or are unable to perform the tests/repairs safely, con-  
tact the Lincoln Electric Service Department for technical troubleshooting assistance before you proceed call 216-  
383-2531 or 1-800-833-9353  
WIRE-MATIC 255  
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F-10  
F-10  
TROUBLESHOOTING & REPAIR  
MAIN TRANSFORMER TEST  
WARNING  
Service and repair should be performed only by Lincoln Electric factory trained per-  
sonnel. Unauthorized repairs performed on this equipment could result in danger to  
the technician or the machine operator and will invalidate your factory warranty. For  
your safety and to avoid electrical shock, please observe all safety notes and pre-  
cautions detailed throughout this manual.  
If for any reason you do not understand the test procedures or are unable to perform  
the tests/repairs safely, contact the Lincoln Electric service department for technical  
troubleshooting assistance before you proceed.  
Call (216) 383-2531 or (800) 833-9353 (WELD).  
_____________________________________________________________  
TEST DESCRIPTION  
This test will determine if the correct voltages are being:  
a. Applied to the primary windings of the Main Transformer.  
b. Induced on the secondary and auxiliary windings of the main transformer.  
MATERIALS NEEDED  
5/16" Nut Driver.  
Volt-Ohm Meter.  
WIRE-MATIC 255  
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F-11  
F-11  
TROUBLESHOOTING & REPAIR  
MAIN TRANSFORMER TEST  
TEST PROCEDURE  
WARNING  
The ON/OFF POWER SWITCH will be  
"hot" during these tests.  
__________________________  
NOTE: Secondary voltages will vary  
proportionably with the primary input  
voltage.  
1. Disconnect the main input power  
supply to the machine.  
2. Remove the Case Top and Side  
Panels with a 5/16" nut driver.  
3. Locate Plug J3 and Plug J6 on the  
G2803 Control PC Board.  
NOTE: The location of Plugs may vary  
depending on the machine code.  
#202  
(1J3)  
J3  
#204A (2J3)  
#203  
(3J3)  
#206  
(4J6)  
J9  
#209  
(7J6)  
J6  
J4  
#208  
(16J6)  
J5  
J10  
J1  
J7  
J2  
FIGURE F.1 - G2803 Control PC  
Board Main Transformer Test Points.  
WIRE-MATIC 255  
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F-12  
F-12  
TROUBLESHOOTING & REPAIR  
MAIN TRANSFORMER TEST (CONTINUED)  
4. Locate the following leads on Plug  
Board.  
J3:  
G2803:  
a. Turn the machine OFF between  
each test.  
LEAD  
PLUG  
LOCATION  
b. Carefully insert the meter  
probes into the back of each  
Molex Plug pin cavity to perform  
the test.  
#202  
#203  
#204 A  
1J3  
3J3  
2J3  
G2803:  
TO  
LEAD  
EXPECTED  
VOLTAGE  
FROM  
LEAD  
5. Connect main input power to the  
machine.  
#209  
(7J6)  
60 VAC  
30 VAC  
30 VAC  
#208  
(16J6)  
6. Turn the Wire-Matic 255 ON/OFF  
POWER SWITCH to ON.  
#206  
(4J6)  
#208  
(16J6)  
7. Make the following voltage tests at  
Plug J3.  
#206  
(4J6)  
#209  
(7J6)  
a. Turn the machine OFF between  
each test.  
b. Carefully insert the meter  
probes into the back of each  
Molex Plug pin cavity to perform  
the test.  
c.  
If any of the voltages tested are  
incorrect, check for loose or bro-  
ken leads between the test  
points and the main transformer.  
G2803:  
d. If ALL the voltages tested are  
incorrect or missing, go to Step  
12.  
TO  
LEAD  
EXPECTED  
VOLTAGE  
FROM  
LEAD  
#203  
(3J3)  
30 VAC  
15 VAC  
15 VAC  
#202  
(1J3)  
12. Test for correct nameplate input volt-  
age between the H1 lead at the  
ON/OFF POWER SWITCH to H2 or  
H3 (H5 if connected for 575 VAC) at  
the reconnect panel. Voltage tested  
will vary depending on Input Voltage  
Connection. See wiring diagram for  
test point locations.  
#204 A  
(2J3)  
#202  
(1J3)  
#204 A  
(2J3)  
#203  
(3J3)  
a. If the voltage test is incorrect,  
8. Turn OFF the machine  
-
check for loose or broken  
9. Locate the following leads on Plug  
J6 on the G2803 Control PC Board.  
G2803:  
leads between the reconnect  
panel and the ON/OFF POWER  
SWITCH.  
LEAD  
PLUG  
LOCATION  
-
test the ON/OFF POWER  
SWITCH for proper operation.  
#206  
#208  
#209  
4J6  
16J6  
7J6  
b. If the correct nameplate voltage  
is being applied to the main  
transformer and one or more of  
the secondary voltages are  
missing or are incorrect, the  
main transformer may be faulty.  
Replace.  
10. Turn ON the machine.  
11. Make the following voltage tests at  
Plug J6 on the G2803 Control PC  
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F-13  
F-13  
TROUBLESHOOTING & REPAIR  
STATIC SCR RECTIFIER ASSEMBLY TEST  
WARNING  
Service and repair should be performed only by Lincoln Electric factory trained per-  
sonnel. Unauthorized repairs performed on this equipment could result in danger to  
the technician or the machine operator and will invalidate your factory warranty. For  
your safety and to avoid electrical shock, please observe all safety notes and pre-  
cautions detailed throughout this manual.  
If for any reason you do not understand the test procedures or are unable to perform  
the tests/repairs safely, contact the Lincoln Electric service department for technical  
troubleshooting assistance before you proceed.  
Call (216) 383-2531 or (800) 833-9353 (WELD).  
_____________________________________________________________  
TEST DESCRIPTION  
This test is used to quickly determine if an SCR or diode is shorted or "leaky." See the  
Machine Waveform Section in this manual for normal and abnormal output waveforms.  
MATERIALS NEEDED  
Analog Ohmmeter (Multimeter).  
Wire-Matic 255 wiring diagrams (See Electrical Diagrams Section of this Manual).  
5/16" Nut Driver.  
1/2" Open end or socket wrench.  
WIRE-MATIC 255  
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F-14  
F-14  
TROUBLESHOOTING & REPAIR  
STATIC SCR RECTIFIER ASSEMBLY TEST (CONTINUED)  
TEST PROCEDURE  
1. Disconnect main AC input power to  
the machine.  
2. Disconnect Plugs J3 and J6 from  
the G2803 Control Board. This  
electrically isolates the SCR bridge  
assembly. See Figure F.2.  
J3  
LEADS  
X2 AND X3  
NEGATIVE  
CAPACITOR  
BANK  
J9  
J6  
BUSS BAR  
J4  
J5  
J10  
J1  
FIGURE F.3 - Location of Leads X2  
and X3.  
J7  
J2  
5. Separate leads X2 and X3 from the  
negative capacitor bank buss bar.  
Be sure there is no electrical con-  
tact. See Figure F.3.  
FIGURE F.2 - Remove Plugs J3 and J6  
to Perform Static SCR Rectifier  
Assembly Test.  
3. Verify that the capacitors have com-  
pletely discharged with an Analog  
Volt-Ohm meter.  
4. Disconnect leads X2 and X3 from  
the negative capacitor bank using a  
1/2" open end wrench. See Figure  
F.3.  
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F-15  
F-15  
TROUBLESHOOTING & REPAIR  
STATIC SCR RECTIFIER ASSEMBLY TEST (CONTINUED)  
NOTE: DO NOT DISASSEMBLE THE  
SCR RECTIFIER HEAT SINK ASSEM-  
BLY.  
6. Test for high or infinite resistance  
from the anode to the cathode of  
SCR 1. See Figure F.4. Use an  
analog ohmmeter (Multimeter).  
FIGURE F.4 - SCR 1 Test Points.  
7. Test for high or infinite resistance  
from the cathode to the anode of  
SCR 1 by reversing the meter leads.  
See Figure F.4.  
a. If a high or infinite resistance is  
indicated for both tests 6 and 7,  
the SCR 1 is not “shorted”.  
b. If a low resistance is indicated in  
either tests 6 or 7, the SCR is  
faulty. Replace SCR Assembly.  
8. Repeat Steps #7 to test SCR 2.  
9. Reconnect leads X2 and X3.  
10. Reconnect Plugs J3 and J6.  
11. If this test did not identify the prob-  
lem or to further test the SCR, go to  
the Active SCR Test.  
WIRE-MATIC 255  
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F-16  
F-16  
TROUBLESHOOTING & REPAIR  
ACTIVE SCR RECTIFIER ASSEMBLY TEST  
WARNING  
Service and repair should be performed only by Lincoln Electric factory trained per-  
sonnel. Unauthorized repairs performed on this equipment could result in danger to  
the technician or the machine operator and will invalidate your factory warranty. For  
your safety and to avoid electrical shock, please observe all safety notes and pre-  
cautions detailed throughout this manual.  
If for any reason you do not understand the test procedures or are unable to perform  
the tests/repairs safely, contact the Lincoln Electric service department for technical  
troubleshooting assistance before you proceed.  
Call (216) 383-2531 or (800) 833-9353 (WELD).  
_____________________________________________________________  
TEST DESCRIPTION  
The Active SCR Test will determine if the device is able to be gated ON and conduct current  
from anode to cathode.  
MATERIALS NEEDED  
An SCR Tester as specified in this procedure.  
Wire-Matic 255 wiring diagrams (See Electrical Diagrams Section of this Manual).  
SCR Heat Sink Assembly Drawings.  
WIRE-MATIC 255  
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F-17  
F-17  
TROUBLESHOOTING & REPAIR  
ACTIVE SCR RECTIFIER ASSEMBLY TEST (CONTINUED)  
TEST PROCEDURE  
1. Disconnect main AC input power to  
the machine.  
2. Disconnect Molex Plugs J3 and J6  
from the G2803 Control Board.  
See Figure F.5.  
LEADS  
X2 AND X3  
J3  
NEGATIVE  
CAPACITOR  
BANK  
J9  
BUSS BAR  
J6  
J4  
FIGURE F.6 - Location of Leads X2  
and X3.  
J5  
J10  
J7  
J1  
J2  
5. Separate leads X2 and X3 from the  
negative capacitor bank buss bar.  
Be sure there is no electrical con-  
tact. See Figure F.6.  
FIGURE F.5 - Control Board Molex  
Plug Locations for G2803 PC Control  
Board.  
NOTE: DO NOT DISASSEMBLE THE  
SCR RECTIFIER HEAT SINK ASSEM-  
BLY.  
3. Verify that the capacitors have com-  
pletely discharged with an Analog  
Volt-Ohm meter.  
6. Construct the circuit shown in Figure  
F.7. One 6-volt lantern battery can  
be used. R1 and R2 resistor values  
are ±10%. Set voltmeter scale low,  
at approximately 0-5 volts or 5-10  
volts.  
4. Disconnect leads X2 and X3 from  
the negative capacitor bank using a  
1/2" open end wrench.  
See Figure F. 6.  
a. Test the voltage level of the bat-  
tery. Short leads (A) and (C).  
Close switch SW-1. Battery  
voltage should be 4.5 volts or  
higher. If lower, replace the bat-  
tery.  
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F-18  
F-18  
TROUBLESHOOTING & REPAIR  
ACTIVE SCR RECTIFIER ASSEMBLY TEST (CONTINUED)  
7. Connect the Tester to the SCR 1 as  
shown in Figure F.7.  
10. Close or keep closed switch SW-1.  
11. Close switch SW-2 for 2 seconds  
and release and read meter.  
a. Connect Tester lead (A) to the  
anode.  
a. If the voltage is 3 - 6 volts while  
the switch is closed and after  
the switch is open, the SCR is  
functioning.  
b. Connect Tester lead (C) to the  
cathode.  
c. Connect Tester lead (G) to the  
gate.  
b. If the voltages is 3-6 volts only  
when the switch is closed or  
there is no voltage when the  
switch is closed, the SCR is  
defective.  
NOTE: Be sure battery is functioning  
properly. A low battery can affect the  
results of the test. Repeat Battery Test  
Procedure in Step 6 if needed.  
12. Open switch SW-1.  
13. Reconnect the Tester leads. See  
Figure F.7.  
a. Connect Tester lead (A) to the  
cathode.  
b. Connect Tester lead (C) to the  
anode.  
c. Disconnect Test lead (G) from  
the gate.  
14. Close switch SW-1.  
15. Read meter for zero voltage.  
a. If the voltage is zero, the SCR is  
functioning.  
b. If the voltage is higher than  
zero, the SCR is shorted.  
FIGURE F.7 - SCR Tester Circuit and  
SCR connections.  
8. Close switch SW-1.  
16. Perform the Active Test Procedure  
outlined in Steps 5-13 for SCR 2.  
NOTE: Switch SW-2 should be open.  
9. Read meter for zero voltage.  
17. Replace all SCR assemblies that do  
not pass the above tests.  
a. If the voltage reading is higher  
than zero, the SCR is shorted.  
18. Replace all Molex Plugs onto the  
Control Board and connect leads X2  
and X3.  
WIRE-MATIC 255  
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F-19  
F-19  
TROUBLESHOOTING & REPAIR  
WIRE DRIVE MOTOR AND TACHOMETER FEEDBACK TEST  
WARNING  
Service and repair should be performed only by Lincoln Electric factory trained per-  
sonnel. Unauthorized repairs performed on this equipment could result in danger to  
the technician or the machine operator and will invalidate your factory warranty. For  
your safety and to avoid electrical shock, please observe all safety notes and pre-  
cautions detailed throughout this manual.  
If for any reason you do not understand the test procedures or are unable to perform  
the tests/repairs safely, contact the Lincoln Electric service department for technical  
troubleshooting assistance before you proceed.  
Call (216) 383-2531 or (800) 833-9353 (WELD).  
_____________________________________________________________  
TEST DESCRIPTION  
This test will determine if the wire drive motor and voltage feedback circuit are functioning  
properly.  
MATERIALS NEEDED  
5/16" Nut Driver.  
Volt-Ohmmeter.  
WIRE-MATIC 255  
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F-20  
F-20  
TROUBLESHOOTING & REPAIR  
WIRE DRIVE MOTOR AND TACHOMETER FEEDBACK TEST (CONTINUED)  
TEST PROCEDURE  
NOTE:  
POLARITY MUST BE  
OBSERVED FOR THESE TESTS.  
Test for Correct Wire Drive Motor  
Armature Voltage  
1. Disconnect main input power to the  
machine.  
2. Remove the Case Top and Side  
Panels using a 5/16" nut driver.  
3. Locate Plug J5 on the G2803  
Control Board. See Figure F.8.  
J3  
J9  
J6  
#541 (W)  
(13J5)  
#539 (B)  
(12J5)  
J4  
J5  
J10  
#555  
(1J5)  
J1  
J2  
J7  
#206B  
(2J5)  
#515B  
(3J5)  
FIGURE F.8 - Plug J5 Location on  
G2803 PC Control Board.  
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F-21  
F-21  
TROUBLESHOOTING & REPAIR  
WIRE DRIVE MOTOR AND TACHOMETER FEEDBACK TEST (CONTINUED)  
4. Test for 2 - 25 VDC between lead  
plug location 12J5 #539(B) (posi-  
tive) (12J5) and lead #541(W)  
(13J5) (negative) to determine if the  
correct armature voltage is being  
supplied. See Figure F.8.  
a. If the 15 VDC is present, check  
the leads to the tach circuit.  
b. If the leads are okay and 15  
VDC is present, the correct volt-  
age is being received from the  
Control Board. Go to Feedback  
Test.  
a. Insert probes in to the Molex pin  
cavities.  
5. Pull the gun trigger.  
c. If the 15 VDC is not present and  
the leads are okay, the Control  
Board may be faulty. Replace.  
6. Read meter. Normal DC volts is  
from 2 - 25 VDC. VDC varies  
depending on wire feed speed.  
Test for Feedback Voltage to the  
Control Board  
a. If voltage to the wire drive motor  
armature is zero, check the  
wires between Plug J5 and the  
wire drive motor. (Check J11,  
J12, and J15). See Wiring  
Diagram.  
1. Test for 1.5 - 3.5 VDC between lead  
#555 (positive) (1J5) and lead  
#206B (negative) (2J5) . See Figure  
F.8 for pin locations.  
b. If the wires are okay and voltage  
to the drive motor armature is  
zero, the Control Board may be  
faulty. Replace.  
a. Insert probes into Molex pin  
cavities.  
2. Pull gun trigger.  
c. If the correct DC armature volt-  
age is present at the wire drive  
motor, the motor or motor brush-  
es may be faulty. Test and/or  
replace.  
3. Read meter for 1.5 - 3.5 VDC.  
a. If the 1.5 - 3.5 VDC is present,  
the tach circuit is sending the  
correct feedback signal to the  
Control Board.  
d. If the motor is running at high  
speed and the armature voltage  
is high and uncontrollable, pro-  
ceed with the tachometer test.  
NOTE: IF THE MOTOR IS NOT RUN-  
NING, THE FEEDBACK VOLTAGE MAY  
BE FROM 0 TO 5 VDC.  
b. If the 1.5 - 3.5 VDC is not pre-  
sent or not correct, the Control  
Board is not receiving the prop-  
er feedback voltage from the  
tach circuit. Check the leads  
from the tach circuit to the  
Control Board for loose or bro-  
ken connections.  
Test  
Tachometer  
for  
Supply  
Voltage  
to  
1. Test for 15 VDC between lead  
#515B (positive) (3J5) and lead  
#206B (negative) (2J5) . See Figure  
F.8 for pin locations.  
a. Insert probes into Molex pin  
cavities.  
c. If the leads are okay, the Control  
Board may be faulty. Replace.  
2. Pull gun trigger.  
3. Read meter for 15 VDC.  
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F-22  
F-22  
TROUBLESHOOTING & REPAIR  
NORMAL OPEN CIRCUIT VOLTAGE WAVEFORM  
SCOPE SETTINGS  
This is a typical DC output voltage wave-  
form generated from a properly operating  
machine. Note that each vertical division  
represents 20 volts and that each horizontal  
division represents 2 milliseconds in time.  
Volts/Div . . . . . . . . . . . . . . . . .20 V/Div.  
Horizontal Sweep . . . . . . . . . .2 ms/Div.  
Coupling . . . . . . . . . . . . . . . . . . . . .DC.  
Trigger . . . . . . . . . . . . . . . . . . .Internal.  
Note: Scope probes connected at machine  
output terminals: (+) probe to electrode, (-)  
probe to work.  
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F-23  
F-23  
TROUBLESHOOTING & REPAIR  
TYPICAL OUTPUT VOLTAGE WAVEFORM - MACHINE LOADED  
MACHINE LOADED TO 250 AMPS AT 26 VDC  
SCOPE SETTINGS  
This is a typical DC output voltage wave-  
form generated from a properly operating  
machine. Note that each vertical division  
represents 20 volts and that each horizontal  
division represents 5 milliseconds in time.  
The machine was loaded with a resistance  
grid bank.  
Volts/Div . . . . . . . . . . . . . . . . .20 V/Div.  
Horizontal Sweep . . . . . . . . . .5 ms/Div.  
Coupling . . . . . . . . . . . . . . . . . . . . .DC.  
Trigger . . . . . . . . . . . . . . . . . . .Internal.  
Note: Scope probes connected at machine  
output terminals: (+) probe to electrode, (-)  
probe to work.  
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F-24  
F-24  
TROUBLESHOOTING & REPAIR  
ABNORMAL OUTPUT VOLTAGE WAVEFORM - MACHINE LOADED  
ONE OUTPUT SCR NOT FUNCTIONING  
MACHINE LOADED TO 220 AMPS AT 22 VDC  
SCOPE SETTINGS  
This is NOT a typical DC output voltage  
waveform. One output SCR is not function-  
ing. Note the increased ripple content. One  
SCR gate was disconnected to simulate an  
open or non-functioning output SCR. Each  
vertical division represents 20 volts and  
each horizontal division represents 5 mil-  
liseconds in time. The machine was loaded  
with a resistance grid bank.  
Volts/Div . . . . . . . . . . . . . . . . .20 V/Div.  
Horizontal Sweep . . . . . . . . . .5 ms/Div.  
Coupling . . . . . . . . . . . . . . . . . . . . .DC.  
Trigger . . . . . . . . . . . . . . . . . . .Internal.  
Note: Scope probes connected at machine  
output terminals: (+) probe to electrode, (-)  
probe to work.  
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F-25  
F-25  
TROUBLESHOOTING & REPAIR  
ABNORMAL OPEN CIRCUIT VOLTAGE  
OUTPUT CAPACITOR BANK NOT FUNCTIONING  
SCOPE SETTINGS  
This is NOT the typical DC output voltage  
waveform. The output capacitors are not  
functioning. Note the lack of “filtering” in the  
output waveform. The output capacitor  
bank was disconnected. Each vertical divi-  
sion represents 20 volts and each horizontal  
division represents 5 milliseconds in time.  
Volts/Div . . . . . . . . . . . . . . . . .20 V/Div.  
Horizontal Sweep . . . . . . . . . .5 ms/Div.  
Coupling . . . . . . . . . . . . . . . . . . . . .DC.  
Trigger . . . . . . . . . . . . . . . . . . .Internal.  
Note: Scope probes connected at machine  
output terminals: (+) probe to electrode, (-)  
probe to work.  
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F-26  
F-26  
TROUBLESHOOTING & REPAIR  
TYPICAL SCR GATE VOLTAGE WAVEFORM  
SCOPE SETTINGS  
This is a typical SCR gate pulse voltage  
waveform. The machine was in an open cir-  
cuit condition (no load) and operating prop-  
erly. Note that each vertical division repre-  
sents 2 volts and each horizontal division  
represents 5 milliseconds in time.  
Volts/Div . . . . . . . . . . . . . . . . . .2 V/Div.  
Horizontal Sweep . . . . . . . . . .5 ms/Div.  
Coupling . . . . . . . . . . . . . . . . . . . . .DC.  
Trigger . . . . . . . . . . . . . . . . . . .Internal.  
Note: Scope probes connected at Plug J3  
on the control board. The (+) probe to lead  
G2, and the (-) probe to lead 204.  
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F-27  
F-27  
TROUBLESHOOTING & REPAIR  
CONTROL PC BOARD REMOVAL AND REPLACEMENT  
WARNING  
Service and repair should be performed only by Lincoln Electric factory trained per-  
sonnel. Unauthorized repairs performed on this equipment could result in danger to  
the technician or the machine operator and will invalidate your factory warranty. For  
your safety and to avoid electrical shock, please observe all safety notes and pre-  
cautions detailed throughout this manual.  
If for any reason you do not understand the test procedures or are unable to perform  
the tests/repairs safely, contact the Lincoln Electric service department for technical  
troubleshooting assistance before you proceed.  
Call (216) 383-2531 or (800) 833-9353 (WELD).  
_____________________________________________________________  
CAUTION  
Printed Circuit Boards can be damaged by static electricity. Follow static handling  
guidelines detailed in “PC Board Troubleshooting Procedures” at the beginning of  
this chapter.  
_______________________________________________________  
REMOVAL AND REPLACEMENT PROCEDURE  
MATERIALS NEEDED  
5/16" Nutdriver.  
Phillips head screwdriver.  
Static electricity grounding strap.  
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F-28  
F-28  
TROUBLESHOOTING & REPAIR  
CONTROL PC BOARD REMOVAL AND REPLACEMENT (CONTINUED)  
4. Carefully remove the P.C. Board  
REMOVAL AND REPLACE-  
MENT PROCEDURE  
from the mounting standoffs. See  
Figure F.10.  
1. Disconnect main input power the  
machine.  
2. Remove the Case Top and Side  
Panels using 5/16" nut driver.  
3. Disconnect all wiring harness plugs  
and Molex Plugs connected to the  
Control Board. See Figure F.9.  
J3  
J9  
J6  
J5  
J4  
FIGURE F.10 - Control Board  
Mounting Locations may vary  
with different Code Machines.  
J1  
J7  
J2  
J10  
5. Lift the Control Board straight up  
and out from the machine.  
FIGURE F.9 - Wiring Harness and  
Molex Plug Locations.  
6. When re-installing the Control  
Board carefully secure Board to  
mounting standoffs.  
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F-29  
F-29  
TROUBLESHOOTING & REPAIR  
WIRE DRIVE ASSEMBLY REMOVAL AND REPLACEMENT  
WARNING  
Service and repair should be performed only by Lincoln Electric factory trained per-  
sonnel. Unauthorized repairs performed on this equipment could result in danger to  
the technician or the machine operator and will invalidate your factory warranty. For  
your safety and to avoid electrical shock, please observe all safety notes and pre-  
cautions detailed throughout this manual.  
If for any reason you do not understand the test procedures or are unable to perform  
the tests/repairs safely, contact the Lincoln Electric service department for technical  
troubleshooting assistance before you proceed.  
Call (216) 383-2531 or (800) 833-9353 (WELD).  
_____________________________________________________________  
MATERIALS NEEDED  
Large slot head screwdriver.  
5/16" Nut Driver.  
Small slot head screwdriver.  
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F-30  
F-30  
TROUBLESHOOTING & REPAIR  
WIRE DRIVE ASSEMBLY REMOVAL AND REPLACEMENT (CONTINUED)  
PROCEDURE  
1. Disconnect main input power to the  
machine.  
2. Remove the Case Top and Side  
Panels.  
3. Using the 5/16” Nutdriver remove  
the gear box top cover.  
4. Remove the two sheet metal screws  
located on the left rear side of the  
gear box housing using a 5/16” nut-  
driver.  
5. Remove the drive roll. See Figure  
F.11.  
a. Remove the thumb screw, drive  
hub, and the spacer.  
6. Remove the screw holding the gun  
connector assembly to the Case  
Front Panel. See Figure F.11.  
7. Slide the entire wire drive assembly  
carefully toward the Case Back and  
approximately 2” (51 mm) away  
from the center baffle to gain access  
to the drive motor and wiring.  
FIGURE F.11 - Wire Drive Assembly  
Removal  
10. Disconnect molex plugs J15, J12,  
and J11. See wiring diagram.  
a. The gas hose and gun connec-  
tor leads will limit the travel dis-  
tance.  
11. Remove the drive roll assembly.  
8. Disconnect the drive motor from the  
drive roll assembly.  
a. Remove the two screws mount-  
ing the drive roll assembly to the  
insulator board using a 5/16” nut  
driver.  
a. Remove the three large phillips  
head screws on the outboard  
side of the drive roll assembly  
face plate using a phillips head  
screw driver.  
b. Loosen the set screw using a  
slot head screwdriver that holds  
the outgoing guide tube into the  
drive roll assembly.  
9. Separate the drive roll assembly  
from the drive motor.  
c. Remove the drive assembly by  
sliding it off the out going guide  
tube and towards the Case  
Back at the rear of the machine.  
a. Grip the drive motor in one hand  
and the drive assembly in the  
other hand.  
b. Wiggle the drive motor and drive  
assembly gently back and forth  
until the two parts separate.  
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F-31  
F-31  
TROUBLESHOOTING & REPAIR  
SCR OUTPUT RECTIFIER REMOVAL & REPLACEMENT  
WARNING  
Service and repair should be performed only by Lincoln Electric factory trained per-  
sonnel. Unauthorized repairs performed on this equipment could result in danger to  
the technician or the machine operator and will invalidate your factory warranty. For  
your safety and to avoid electrical shock, please observe all safety notes and pre-  
cautions detailed throughout this manual.  
If for any reason you do not understand the test procedures or are unable to perform  
the tests/repairs safely, contact the Lincoln Electric service department for technical  
troubleshooting assistance before you proceed.  
Call (216) 383-2531 or (800) 833-9353 (WELD).  
_____________________________________________________________  
MATERIALS NEEDED  
5/16" Nut driver.  
1/2" Open end wrench.  
1/2" Socket wrench, universal tool, and extension.  
3/8" Open end wrench.  
Slot head screwdriver.  
Wire cutters.  
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F-32  
F-32  
TROUBLESHOOTING & REPAIR  
SCR OUTPUT RECTIFIER REMOVAL & REPLACEMENT (CONTINUED)  
4. Cut the SCR gate leads G1 and G2  
PROCEDURE  
(see wire markers and wiring dia-  
gram) using wire cutters.  
1. Disconnect  
lead  
#208  
and  
Transformer Lead X1 from the heat  
sink on the left side of the machine  
(facing the front) using a 1/2" socket  
wrench. See Figure F.12.  
a. The easiest access to these  
leads is from the right side of the  
machine.  
b. Cut any necessary cable ties.  
a. Thin lead is always on the out-  
board side of the connection.  
5. Remove the four screws holding the  
SCR Assembly to the floor of the  
machine using a 5/16" nut driver.  
6. Pivot the SCR Assembly counter-  
clockwise to provide access to the  
right side heat sink.  
See Figure F.14.  
FIGURE F.12 - Heat Sink lead discon-  
nection.  
2. Disconnect lead #204 and heavy  
lead from the middle heat sink with a  
1/2" socket wrench and 1/2" open  
end wrench. See Figure F.13.  
FIGURE F.14 - Heat Sink Lead  
Disconnection  
3. Remove the diode lead from the  
negative capacitor band buss bar on  
the right side of the machine using a  
slot head screwdriver and 3/8" open  
end wrench.  
7. Remove lead #209 and Transformer  
Lead X4 from the right side heat sink  
using a 1/2" socket wrench and 1/2"  
open end wrench.  
8. Clear the leads and carefully  
remove the SCR Rectifier Assembly.  
NOTE: When installing the SCR  
Rectifier Assembly, apply a thin coating  
of Dow Corning #340 Compound to the  
electrical connections.  
FIGURE F.13 - Heat Sink lead discon-  
nection.  
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F-33  
F-33  
TROUBLESHOOTING & REPAIR  
CAPACITOR BANK REMOVAL AND REPLACEMENT  
WARNING  
Service and repair should be performed only by Lincoln Electric factory trained per-  
sonnel. Unauthorized repairs performed on this equipment could result in danger to  
the technician or the machine operator and will invalidate your factory warranty. For  
your safety and to avoid electrical shock, please observe all safety notes and pre-  
cautions detailed throughout this manual.  
If for any reason you do not understand the test procedures or are unable to perform  
the tests/repairs safely, contact the Lincoln Electric service department for technical  
troubleshooting assistance before you proceed.  
Call (216) 383-2531 or (800) 833-9353 (WELD).  
_____________________________________________________________  
WARNING  
THE LIQUID ELECTRODE IN THE CAPACITORS IS TOXIC. DO NOT TOUCH THE CAPAC-  
ITORS WITH ANY PART OF YOUR BODY.  
_____________________________________________________________  
MATERIALS NEEDED  
5/16" Nut driver.  
5/16" Socket wrench, extension, and universal tool.  
1/2" Open end wrench.  
3/8" Open end wrench.  
Slot head screwdriver.  
Wiring diagram.  
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F-34  
F-34  
TROUBLESHOOTING & REPAIR  
CAPACITOR BANK REMOVAL AND REPLACEMENT (CONTINUED)  
6. Remove the #204 lead from the pos-  
PROCEDURE  
itive buss bar.  
See Figure F.15 for location of Capacitor  
7. Remove the shunt from the negative  
Bank Removal and Replacement com-  
capacitor bank buss bar using a 1/2"  
ponents.  
socket wrench with a universal tool  
adapter.  
a. Two people may be required to  
remove the shunt. One person  
may have to reach through from  
the left side of the machine to  
keep the bolt in position while  
the other person loosens the  
nut.  
8. Remove the two screws holding the  
capacitor bank to the floor of the  
machine using a 5/16" nut driver.  
9. Clear the leads and carefully  
remove the capacitor bank assem-  
bly from the machine.  
FIGURE F.15 - Location of Capacitor  
Bank Removal and Replacement  
Components.  
1. Disconnect main input power to the  
machine.  
2. Test that the capacitors are dis-  
charged using a volt ohmmeter.  
Polarity must be observed.  
3. Remove the two transformer sec-  
ondary leads (X2 and X3) for the  
negative capacitor bank buss bar  
using two 1/2" open end wrenches.  
4. Remove the output choke lead and  
the heavy lead extending from the  
SCR Rectifier Assembly to the posi-  
tive capacitor bank buss bar using a  
1/2" open end wrench.  
5. Remove lead #206 and the D1  
diode lead from the negative capac-  
itor bank buss bar using a slot head  
screwdriver and 3/8" open end  
wrench.  
WIRE-MATIC 255  
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F-35  
F-35  
TROUBLESHOOTING & REPAIR  
MAIN TRANSFORMER REMOVAL AND REPLACEMENT  
WARNING  
Service and repair should be performed only by Lincoln Electric factory trained per-  
sonnel. Unauthorized repairs performed on this equipment could result in danger to  
the technician or the machine operator and will invalidate your factory warranty. For  
your safety and to avoid electrical shock, please observe all safety notes and pre-  
cautions detailed throughout this manual.  
If for any reason you do not understand the test procedures or are unable to perform  
the tests/repairs safely, contact the Lincoln Electric service department for technical  
troubleshooting assistance before you proceed.  
Call (216) 383-2531 or (800) 833-9353 (WELD).  
_____________________________________________________________  
MATERIALS NEEDED  
5/16" Nut Driver.  
1/2" Open end wrench.  
3/8" Open end wrench.  
1/2" Socket wrench, extender, universal adapter.  
Wire cutters.  
WIRE-MATIC 255  
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F-36  
F-36  
TROUBLESHOOTING & REPAIR  
MAIN TRANSFORMER REMOVAL AND REPLACEMENT (CONTINUED)  
12. Disconnect the positive output lead  
PROCEDURE  
at the wire drive motor.  
1. Disconnect main input power to the  
13. Remove the strain relief grommet  
machine.  
through which the positive output  
lead passes through the horizontal  
baffle of the machine.  
Panels.  
2. Remove the Case Top and Side  
14. Pull down on the positive output  
3. Perform the Capacitor Bank  
lead until it slides out the hole in the  
Removal Procedure.  
baffle.  
4. Remove lead X1 from the left side  
15. Carefully remove the main trans-  
SCR heat sink assembly using a  
former.  
1/2" socket wrench, extender and  
universal adapter.  
a. Be sure all leads are clear.  
5. Remove lead X4 from the right side  
heat sink assembly using a 1/2"  
socket wrench, extender and univer-  
sal adapter.  
6. Disconnect all leads from the recon-  
nect panel using a 3/8" open end  
wrench.  
7. Disconnect all leads from the  
POWER SWITCH.  
8. Remove the POWER SWITCH.  
9. Label and cut leads #202, #203,  
#204A.  
a. Cut lead #204A at a point just in  
front of the transformer.  
b. These leads must be re-spliced  
during reassembly.  
c. An alternative to cutting these  
leads is to remove them from  
Molex Plug J3 and pull them  
free of any wire bundles.  
10. Remove all cable ties, wire mounts,  
- and any harness tape that could  
get in the way during transformer  
removal using wire cutters and  
screwdriver.  
11. Remove the four screws mounting  
the transformer to the floor of the  
machine using a 5/16" nut driver.  
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F-37  
F-37  
TROUBLESHOOTING & REPAIR  
FAN MOTOR AND FAN REMOVAL AND REPLACEMENT  
WARNING  
Service and repair should be performed only by Lincoln Electric factory trained per-  
sonnel. Unauthorized repairs performed on this equipment could result in danger to  
the technician or the machine operator and will invalidate your factory warranty. For  
your safety and to avoid electrical shock, please observe all safety notes and pre-  
cautions detailed throughout this manual.  
If for any reason you do not understand the test procedures or are unable to perform  
the tests/repairs safely, contact the Lincoln Electric service department for technical  
troubleshooting assistance before you proceed.  
Call (216) 383-2531 or (800) 833-9353 (WELD).  
_____________________________________________________________  
MATERIALS NEEDED  
3/4" Open end wrench.  
1/2" Socket wrench with extension.  
Phillips head screwdriver.  
WIRE-MATIC 255  
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F-38  
F-38  
TROUBLESHOOTING & REPAIR  
FAN MOTOR AND FAN REMOVAL AND REPLACEMENT (CONTINUED)  
PROCEDURE  
See Figure F.16 for fan motor and fan  
removal components.  
FIGURE F.16 - Fan Motor and Fan  
Removal Components  
5. Loosen the two screws holding the  
reconnect panel in place and a slide  
the reconnect panel from the frame.  
1. Remove the Case Back screws.  
2. Remove the gas solenoid using a  
3/4" open end wrench.  
6. Remove the fan blade. Note fan  
blade position on motor shaft for ref-  
erence for replacing fan.  
3. Using a 5/16” wrench, remove the 5  
screws holding the fan motor mount-  
ing bracket to the case back.  
a. Pry the fan blade off the motor.  
4. Tilt the Case Back away from the  
machine and remove the screws  
holding the Case Back to the floor of  
the machine using a 1/2" socket  
wrench with extension.  
b. Slide the fan blade off the motor  
shaft.  
WIRE-MATIC 255  
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F-39  
F-39  
TROUBLESHOOTING & REPAIR  
FAN MOTOR AND FAN REMOVAL AND REPLACEMENT (CONTINUED)  
7. Remove the fan motor.  
a. Loosen and remove the two  
screws from the motor mounting  
bracket using a slot head screw  
driver.  
b. When the motor is free from the  
mounting bracket, place it care-  
fully on the bottom of the  
machine.  
c. Cut any necessary wire wraps  
bundling the motor leads.  
d. Remove the leads from the fan  
motor.  
8. Install the replacement motor in the  
reverse order of removal.  
9. Install the fan blade.  
When  
installing the fan blade, the blade is  
flush with the end of the motor shaft.  
a. Spin the fan to be sure it is free  
to rotate.  
10. Reassemble the remaining compo-  
nents in reverse order of removal.  
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F-40  
F-40  
TROUBLESHOOTING & REPAIR  
RETEST AFTER REPAIR  
INPUT IDLE AMPS AND WATTS  
Input Volts/Hertz  
Maximum Idle Amps  
Maximum Idle Watts  
230/60  
6.4  
375  
OPEN CIRCUIT VOLTAGE  
35-40 VDC Strike Voltage  
10 to 40 VDC  
WIRE SPEED RANGE  
50 - 600 IPM (1.27 - 15.2 m/minute)  
WIRE-MATIC 255  
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NOTES  
WIRE-MATIC 255  
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G-1  
G-1  
TABLE OF CONTENTS  
- ELECTRICAL DIAGRAMS SECTION -  
Electrical Diagram Section . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Section G  
Wiring Diagram (208/230) Code 10166 . . . . . . . . . . . . . . . . . . . . . . . . . G-2  
Wiring Diagram (230/460/575) Code 10167 . . . . . . . . . . . . . . . . . . . . . . G-3  
Control PC Board (G2803) Schematic . . . . . . . . . . . . . . . . . . . . . . . . . . G-4  
Control PC Board (G2803) Layout . . . . . . . . . . . . . . . . . . . . . . . . . . . . . G-5  
WIRE-MATIC 255  
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NOTES  
WIRE-MATIC 255  
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G-2  
G-2  
ELECTRICAL DIAGRAMS  
Wiring Diagram (208/230) Code 10166  
WIRE - MATIC 255 (208 / 230V)  
GENERAL INFORMATION  
ELECTRICAL SYMBOLS PER E1537  
COLOR CODE:  
1
2
OPTIONAL  
TIMER  
*
CONTROL BOARD  
(J7)  
1
260  
262  
261  
263  
265  
264  
266  
267  
(J8)  
*
392  
390  
*
3
4
BOARD  
2
J16  
(J4)  
3
4
B
W
R
U
-
-
-
-
BLACK  
WHITE  
RED  
*
1
2
3
4
*
J1  
5
6
(J9)  
BLUE  
1
2
3
4
5
6
7
8
1
2
3
4
5
6
7
8
INDICATES CONNECTOR CAVITY NO.  
7
8
*
SCI TEST  
PLUG  
1
2
3
4
5
6
1
R.F.  
CHOKE  
AS'BLY  
2
3
4
251  
*
* *  
5
6
1
J2  
1
2
202  
204A  
J21  
1
555  
2
WIRE SPEED  
252  
1
2
3
7
8
9
206B  
515B  
2
SPI TEST  
PLUG  
3
4
203  
3
4
5
3
4
206  
207  
GND  
209  
392B  
390A  
325  
5
6
G1  
204  
G2  
4
10  
5
6
6
7
(J3)  
7
8
9
*
1
254  
252  
253  
255  
251  
256  
(J5)  
256  
324  
7
8
9
* *  
*
(J6)  
8
9
2
3
4
*
ARC VOLTAGE  
253  
GAS  
J20  
10  
J10  
10  
11  
SOLENOID  
SPOOL GUN ADAPTER  
HARNESS  
10  
205  
11  
12  
5
6
11  
12  
12  
254  
255  
B
206S  
325A  
320  
+
-
13  
515  
325A  
324A  
1
2
3
POWER-ON  
INDICATOR  
13  
14  
W
14  
15  
TO  
208  
16  
206A  
541A  
4
5
6
SPOOL GUN  
OPTION  
495  
542  
543  
392  
7
8
* *  
9
GND  
J15  
* *  
390  
392B  
10  
11  
12  
13  
14  
J14  
515B  
1
515B  
390A  
2
3
4
5
6
555  
B
555  
B
1
2
* *  
JUMPER USED WITHOUT  
SPOOL GUN OPTION  
2
1
325  
324  
325  
GUN  
TRIGGER  
J11  
206B  
206B  
3
4
B
1
324  
W
W
2
W
TO  
WORK  
N.A.  
MOTOR/  
GEARBOX  
R.F.  
CHOKE  
AS'BLY.  
R.F.  
CHOKE  
A* S* 'BLY.  
W
T
R
U
B
515B  
555  
P.M.  
* *  
A
C
H
J12  
1
J13  
NOTES  
206B  
B
N.A. WELDING CABLE MUST BE OF PROPER CAPACITY FOR THE  
CURRENT AND DUTY CYCLE OF IMMEDIATE AND  
FUTURE APPLICATIONS.  
206  
1
207  
B
W
2
325  
2
3
4
320  
328  
325A  
N.B. THIS DIAGRAM SHOWS THE "ELECTRODE" POLARITY  
"POSITIVE". TO CHANGE POLARITY, TURN THE UNIT  
OFF AND REVERSE LEAD CONNECTIONS AT CABLE  
CONDUCTOR STRAP AND WORK STUD.  
N.C.  
324  
N.D.  
TO SINGLE PHASE  
SUPPLY LINE  
L1  
R.F. FILTER  
THERMOSTAT  
S3  
THERMOSTAT  
S4  
N.B.  
N.C. THERMOSTATS MOUNTED ON CHOKE COIL  
S2 MOUNTED CLOSEST TO FAN; S3 MOUNTED CLOSEST TO  
POWER TRANSFORMER.  
L2  
X5  
202  
204A  
203  
N.D. THERMOSTAT S4 MOUNTED ON FAN SENSOR BRACKET  
.
H4  
W
P2  
X6  
N.E. RESISTOR R2 MOUNTED ON FAN SENSOR BRACKET.  
GND  
H2  
H3  
HIGH V.  
TO GROUND PER  
NATIONAL ELECTRICAL  
CODE  
X7  
X1  
208  
L1  
LOW V.  
JUMPER  
G1  
H1  
B
SCR  
1
H1  
250V  
470A  
204  
L2  
X2  
L1  
L2  
SCR HEATSINK  
ASBLY  
GND.  
RECONNECT PANEL  
H2  
H2  
H3  
X3  
SCR  
2
250V  
470A  
G
CAVITY  
X4  
G2  
N.C.  
H4  
T1  
H1  
H3  
POWER TRANSFORMER  
CAVITY NUMBERING SEQUENCE  
NUMBERING SEQUENCE  
209  
SHUNT  
P2  
D1  
300V  
85A  
(COMPONENT SIDE OF P.C. BOARD)  
(NON-LEAD SIDE OF CONNECTOR)  
T1  
T2  
P1  
P2  
+
-
H1  
1
3
2
4
1
3
2
FAN  
J13  
J14  
J21  
LINE  
SWITCH  
S1  
206  
S2  
THERMOSTAT  
J11  
J12  
MOTORS  
J15  
205  
1
4
6
15 OHMS  
100  
1
6
1
5
4
8
1
6
5
W
J1  
J4  
J16  
C1 THRU C4  
30,000 MFD  
50V  
C1  
C2  
C3  
C4  
206S  
1
7
R2  
J3  
J2  
2.5K  
10W  
204  
+
+
+
+
J20  
7
12  
OUTPUT  
CHOKE  
10  
N.E.  
8
14  
207  
1
7
1
8
J5  
J6  
8
14  
9
16  
1
3
2
4
1
4
3
J7  
J8  
J9  
J10  
6
C-RW  
L9690  
NOTE: This diagram is for reference only. It may not be accurate for all machines covered by this manual. The specific diagram for a particular code is pasted inside the machine on one of the enclosure panels.  
WIRE-MATIC 255  
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G-3  
G-3  
ELECTRICAL DIAGRAMS  
Wiring Diagram (230/460/575) Code 10167  
WIRE - MATIC 255 (230 / 460 / 575V)  
GENERAL INFORMATION  
ELECTRICAL SYMBOLS PER E1537  
COLOR CODE:  
1
OPTIONAL  
TIMER  
*
CONTROL BOARD  
(J7)  
2
3
4
1
260  
262  
261  
263  
265  
264  
266  
267  
*
(J8)  
*
392  
390  
BOARD  
2
J16  
(J4)  
3
4
*
B
W
R
U
-
-
-
-
BLACK  
WHITE  
RED  
1
2
3
4
*
J1  
5
6
(J9)  
1
2
3
4
5
6
7
8
1
2
3
4
5
6
7
8
BLUE  
7
8
SCI TEST  
PLUG  
INDICATES CONNECTOR CAVITY NO.  
*
1
2
3
4
5
6
1
R.F.  
2
3
4
CHOKE  
AS'BLY  
* *  
* *  
251  
1
2
3
*
J21  
5
6
1
J2  
1
2
202  
204A  
392B  
390A  
1
555  
2
WIRE SPEED  
252  
4
7
8
9
206B  
515B  
2
SPI TEST  
PLUG  
3
4
203  
3
4
5
3
4
206  
207  
GND  
209  
325  
5
6
G1  
204  
G2  
10  
5
6
J20  
6
7
GAS  
SOLENOID  
(J3)  
7
8
9
*
1
254  
252  
253  
255  
251  
256  
(J5)  
256  
324  
7
8
9
*
(J6)  
SPOOL GUN ADAPTER  
HARNESS  
8
9
2
3
4
*
ARC VOLTAGE  
253  
10  
J10  
515  
1
2
3
10  
11  
10  
205  
11  
12  
325A  
324A  
5
6
11  
12  
12  
254  
255  
B
W
206S  
325A  
320  
+
-
13  
TO  
206A  
541A  
4
POWER-ON  
INDICATOR  
13  
14  
14  
15  
5
6
SPOOL GUN  
OPTION  
495  
208  
16  
542  
543  
392  
7
8
9
390  
392B  
10  
11  
12  
13  
14  
* *  
390A  
GND  
* *  
J15  
JUMPER USED WITHOUT  
SPOOL GUN OPTION  
J14  
515B  
1
515B  
* *  
2
3
4
5
6
555  
B
555  
B
1
2
3
4
J11  
1
2
325  
324  
325  
GUN  
TRIGGER  
206B  
206B  
B
324  
1
W
W
W
2
TO  
WORK  
N.A.  
R.F.  
R.F.  
W
CHOKE  
AS'BLY  
CHOKE  
AS'BLY  
MOTOR/  
R
T
515B  
555  
GEARBOX  
* *  
NOTES  
A
C
H
P.M.  
U
B
J12  
N.A. WELDING CABLE MUST BE OF PROPER CAPACITY FOR THE  
CURRENT AND DUTY CYCLE OF IMMEDIATE AND  
FUTURE APPLICATIONS.  
206B  
1
2
B
1
325  
206  
207  
N.B. THIS DIAGRAM SHOWS THE "ELECTRODE" POLARITY  
"POSITIVE". TO CHANGE POLARITY, TURN THE UNIT  
OFF AND REVERSE LEAD CONNECTIONS AT CABLE  
CONDUCTOR STRAP AND WORK STUD.  
3
4
B
W
2
324  
320  
328  
N.D.  
325A  
* *  
N.C.  
J13  
TO SINGLE PHASE  
N.C. THERMOSTATS MOUNTED ON CHOKE COIL  
S2 MOUNTED CLOSEST TO FAN; S3 MOUNTED CLOSEST TO  
POWER TRANSFORMER.  
R.F. FILTER  
SUPPLY LINE  
L1  
THERMOSTAT  
S3  
THERMOSTAT  
S4  
N.B.  
N.D. THERMOSTAT S4 MOUNTED ON FAN SENSOR BRACKET  
.
N.E. RESISTOR R2 MOUNTED ON FAN SENSOR BRACKET.  
L2  
X5  
202  
204A  
203  
5
H5  
X6  
GND  
L1  
L2  
TO GROUND PER  
X7  
X1  
208  
T1  
NATIONAL ELECTRICAL  
CODE  
H2  
4
2
G1  
SCR  
250V  
470A  
1
H1  
P2  
H2  
204  
H4  
H3  
1
3
X2  
L1  
L2  
H5  
SCR HEATSINK  
ASBLY  
H3  
X3  
SCR  
250V  
470A  
2
H1  
CAVITY  
RECONNECT PANEL  
(SHOWN CONNECTED  
FOR 230 VOLT.)  
GND.  
X4  
CAVITY NUMBERING SEQUENCE  
NUMBERING SEQUENCE  
G2  
H4  
H1  
G
H4  
POWER TRANSFORMER  
209  
(COMPONENT SIDE OF P.C. BOARD)  
(NON-LEAD SIDE OF CONNECTOR)  
SHUNT  
D1  
300V  
85A  
N.C.  
1
3
2
4
1
3
2
+
-
J13  
J14  
J21  
H1  
J11  
J12  
P2  
P2  
J15  
LINE  
SWITCH  
S1  
206  
T1  
T2  
P1  
1
4
6
1
6
1
5
4
8
1
6
5
FAN  
205  
J1  
J4  
J16  
15 OHMS  
100  
S2  
THERMOSTAT  
1
7
MOTORS  
J3  
J2  
W
C1 THRU C4  
30,000 MFD  
50V  
C1  
C2  
C3  
C4  
206S  
J20  
7
12  
10  
204  
+
+
+
+
8
14  
OUTPUT  
CHOKE  
R2  
1
7
1
8
2.5K  
10W  
207  
N.E.  
J5  
J6  
8
14  
9
16  
1
3
2
4
1
4
3
J7  
J8  
J9  
J10  
6
C-RW  
L9691  
NOTE: This diagram is for reference only. It may not be accurate for all machines covered by this manual. The specific diagram for a particular code is pasted inside the machine on one of the enclosure panels.  
WIRE-MATIC 255  
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G-4  
G-4  
ELECTRICAL DIAGRAMS  
Control PC Board (G2803) Schematic  
NOTE: Lincoln Electric assumes no responsibility for liablilities resulting from board level troubleshooting. PC Board repairs will invalidate your factory warranty. Individual Printed Circuit Board Components are not  
available from Lincoln Electric. This information is provided for reference only. Lincoln Electric discourages board level troubleshooting and repair since it may compromise the quality of the design and may result  
in danger to the Machine Operator or Technician. Improper PC board repairs could result in damage to the machine.  
WIRE-MATIC 255  
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G-5  
G-5  
ELECTRICAL DIAGRAMS  
Control PC Board (G2803) Layout  
G
2 8 0 3  
CAPACITORS  
=
MFD/VOLTS  
RESISTORS  
=
OHMS  
3-24-95A  
THIS SHEET CONTAINS PROPRIETARY INFORMATION  
EQUIP.  
TYPE  
WM-255  
THE LINCOLN ELECTRIC CO.  
CLEVELAND, OHIO U.S.A.  
OWNED BY  
AND IS  
THE LINCOLN ELECTRIC CO.  
NOT TO BE REPRODUCED, DISCLOSED OR USED  
WITHOUT THE EXPRESS PERMISSION OF  
CONTROL P.C. BOARD ASSEMBLY  
SUBJECT  
SCALE  
FULL  
SHT.  
NO.  
THE LINCOLN ELECTRIC CO.  
F.V.  
9-19-94  
FV  
CHK  
REF.  
2803  
DR  
DATE  
SUP'S'D'G  
G
NOTE: Lincoln Electric assumes no responsibility for liablilities resulting from board level troubleshooting. PC Board repairs will invalidate your factory warranty. Individual Printed Circuit Board Components are not  
available from Lincoln Electric. This information is provided for reference only. Lincoln Electric discourages board level troubleshooting and repair since it may compromise the quality of the design and may result  
in danger to the Machine Operator or Technician. Improper PC board repairs could result in damage to the machine.  
WIRE-MATIC 255  
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