SERVICE MANUAL
SG SERIES GAS CONVECTION
OVENS
MODELS
SG4
SG6
SG44
STACKED
MODELS
SG66
- NOTICE -
This Manual is prepared for the use of trained Vulcan Service
Technicians and should not be used by those not properly
qualified.
This manual is not intended to be all encompassing. If you have
not attended a Vulcan Service School for this product, you should
read, in its entirety, the repair procedure you wish to perform to
determine if you have the necessary tools, instruments and skills
required to perform the procedure. Procedures for which you do
not have the necessary tools, instruments and skills should be
performed by a trained Vulcan Service Technician.
The reproduction, transfer, sale or other use of this Manual,
without the express written consent of Vulcan, is prohibited.
This manual has been provided to you by ITW Food Equipment
Group LLC ("ITW FEG") without charge and remains the property
of ITW FEG, and by accepting this manual you agree that you will
return it to ITW FEG promptly upon its request for such return at
any time in the future.
A product of Vulcan-Hart
3600 North Point Blvd Baltimore, MD 21222
F45525 Rev. A (0315)
Download from Www.Somanuals.com. All Manuals Search And Download.
SG SERIES GAS CONVECTION OVENS
© VULCAN 2015
Page 3 of 33
F45525 Rev. A (0315)
Download from Www.Somanuals.com. All Manuals Search And Download.
SG SERIES GAS CONVECTION OVENS - GENERAL
GENERAL
INTRODUCTION
Procedures in this manual will apply to all models unless specified. Pictures and illustrations can be of any model
unless the picture or illustration needs to be model specific.
MODELS
FEATURES
OPTIONS
BLOWER
MODEL
CAVITY
DEPTH
TEMPERTURE
COOK
TIMER
DOORS (50/50)
CASTERS
CONTROL
Solid State
Solid State
208/240/60/1
SG4
SG6
26.5"
30.5"
Independent
Independent
1-Hour Dial
1-Hour Dial
Optional
Optional
Optional
Optional
Natural - Recommend (in. W.C.) 8.0, Min 6.0
Propane - Recommend (in. W.C.) 11.0, Min 11.0
Maximum 14.0 in. W.C. (Nat. or Prop.)
INSTALLATION
Refer to the Installation and Operation Manual for
detailed installation instructions on single or stacked
ovens.
TOOLS
OPERATION
Standard
•
Standard set of hand tools
Refer to the Installation and Operation Manual for
specific operating instructions.
•
VOM with ability to measure micro amp current
VOM with minimum of NFPA-70E CAT III 600V,
UL/CSA/TUV listed. Sensitivity of at least 20,000
ohms per volt. Meter leads must also be rated at
CAT III 600V.
CLEANING
Refer to the Installation and Operation Manual for
specific cleaning instructions.
•
Gear Puller to remove blower
Special
LUBRICATION
•
Temperature tester (thermocouple type)
•
•
Cavity blower motor has sealed bearings and
requires no additional lubrication.
•
Manometer
Huskey™ TF-1000 grease or equivalent high
temperature Teflon grease.
SPECIFICATIONS
Electrical
Voltage - 120/60/1
Amps - 8.0 Amps
Input BTU Rating
Natural Gas - 60,000 BTU input at 5.0 in. W.C.
Propane Gas - 60,000 BTU input at 10.0 in. W.C.
Gas Line Pressures
Page 5 of 33
F45525 Rev. A (0315)
Download from Www.Somanuals.com. All Manuals Search And Download.
SG SERIES GAS CONVECTION OVENS - REMOVAL AND REPLACEMENT OF PARTS
REMOVAL AND REPLACEMENT OF PARTS
COVERS AND PANELS
Disconnect the
electrical power to the machine and
follow lockout / tagout procedures.
SHUT OFF THE GAS BEFORE
SERVICING THE UNIT.
Top Front Cover
1. The top front cover is secured with four (4)
screws, two on each side of cover. Remove these
screws then remove the cover from the oven.
Fig. 3
NOTE: If the oven has a mechanical (KX type)
thermostat, it must be removed from the control panel
first, before removing the control panel.
2. Disconnect the temperature probe leads from the
solid state temperature control.
3. Unplug the wire harness connector to the control
panel components.
4. Reverse the procedure to install.
Right Side Panel
1. Remove the screws which secure the right side
of the top front cover, bottom front cover and
control panel.
Fig. 1
2. Reverse the procedure to install.
Bottom Front Cover
2. Remove the remaining six screws securing the
right side panel.
1. The bottom front cover is secured with four (4)
screws, two on each side of cover. Remove these
screws then remove the cover from the oven.
Fig. 2
2. Reverse the procedure to install.
Control Panel
Fig. 4
3. Pull the right side panel out at the bottom then
down to remove.
1. Remove three (3) screws on the right side which
secure the control panel then pull the panel away
from the oven.
4. Reverse the procedure to install.
F45525 Rev. A (0315)
Page 6 of 33
Download from Www.Somanuals.com. All Manuals Search And Download.
SG SERIES GAS CONVECTION OVENS - REMOVAL AND REPLACEMENT OF PARTS
CONTROL PANEL COMPONENTS
COMPONENT PANEL
COMPONENTS
Disconnect the
electrical power to the machine and
follow lockout / tagout procedures.
Disconnect the
electrical power to the machine and
follow lockout / tagout procedures.
Removable Components Procedure
2. Remove the component being replaced.
Removable Components Procedure
NOTE: If right side panel is not accessible, this
component can be serviced by removing the
3. Reverse the procedure to install the replacement
component, then check oven for proper
operation.
2. Disconnect the wire leads to the component
being replaced.
3. Remove the component.
4. Reverse the procedure to install the replacement
component and check oven for proper operation.
Fig. 5
Page 7 of 33
F45525 Rev. A (0315)
Download from Www.Somanuals.com. All Manuals Search And Download.
SG SERIES GAS CONVECTION OVENS - REMOVAL AND REPLACEMENT OF PARTS
NOTE: If right side panel is not accessible, this
component can be serviced by removing the
2. Disconnect the probe leads from the solid state
temperature control.
3. Remove the racks and right rack support.
4. Remove the probe guard.
Fig. 7
5. Remove probe by pushing it through the oven
wall and into the control panel area.
Fig. 8
NOTE: The hole in the oven cavity wall does not line
up straight with the oven cavity outer shell, therefore
the probe must be removed at an angle.
6. Reverse the procedure to install the replacement
probe.
7. Adjust the temperature control as outlined under
GAS BURNER
Fig. 6
Disconnect the
TEMPERATURE PROBE
electrical power to the machine and
follow lockout / tagout procedures.
Disconnect the
electrical power to the machine and
follow lockout / tagout procedures.
SHUT OFF THE GAS BEFORE
SERVICING THE UNIT.
F45525 Rev. A (0315)
Page 8 of 33
Download from Www.Somanuals.com. All Manuals Search And Download.
SG SERIES GAS CONVECTION OVENS - REMOVAL AND REPLACEMENT OF PARTS
2. Disconnect the ignition cable and the flame
sense lead wire.
Fig. 12
6. Reverse procedure to install the replacement
burner.
Fig. 9
3. Disconnect the ignition cable and the flame
sense lead wire.
NOTE: Ensure that burner positioning bracket (U
shaped end) is inserted into slot at the rear of the
burner chamber.
7. Check for proper operation.
GAS ORIFICE
Fig. 10
Disconnect the
electrical power to the machine and
follow lockout / tagout procedures.
4. Remove the screws securing the burner cover
then lift out.
SHUT OFF THE GAS BEFORE
SERVICING THE UNIT.
2. Remove the bolts securing the gas manifold to
the oven and place the manifold to the side.
Fig. 11
5. Grasp the burner and lift out.
Fig. 13
3. Remove the gas orifice from the spud on the
manifold and replace with the correct orifice for
the given altitude.
Page 9 of 33
F45525 Rev. A (0315)
Download from Www.Somanuals.com. All Manuals Search And Download.
SG SERIES GAS CONVECTION OVENS - REMOVAL AND REPLACEMENT OF PARTS
Fig. 14
4. Reverse procedure to install and check for proper
operation.
GAS SOLENOID VALVE
Fig. 15
Disconnect the
4. Loosen the bolts securing the valve and bracket
electrical power to the machine and
assembly then remove the screws securing the
follow lockout / tagout procedures.
valve to the bracket.
SHUT OFF THE GAS BEFORE
SERVICING THE UNIT.
All gas joints disturbed during
servicing must be checked for leaks. Check with a
soap and water solution (bubbles). Do not use an open
flame.
NOTE: If is right side panel not accessible, this
component can be serviced by removing the
2. Disconnect the lead wires.
3. Disconnect the compression fittings to the valve.
Fig. 16
5. Verify new gas valve is configured for the proper
gas type.
F45525 Rev. A (0315)
Page 10 of 33
Download from Www.Somanuals.com. All Manuals Search And Download.
SG SERIES GAS CONVECTION OVENS - REMOVAL AND REPLACEMENT OF PARTS
Fig. 17
Fig. 19
6. Reverse the procedure to install the replacement
gas valve.
IGNITION CONTROL MODULE
Disconnect the
electrical power to the machine and
follow lockout / tagout procedures.
SHUT OFF THE GAS BEFORE
SERVICING THE UNIT.
NOTE: If right side panel is not accessible, this
component can be serviced by removing the
Fig. 18
A. To change gas type unscrew and reverse
cap to show the proper gas type.
2. Loosen the screws securing the mounting
bracket to the component panel and remove the
bracket.
1) Make sure gasket is positioned
between cap and valve body.
Page 11 of 33
F45525 Rev. A (0315)
Download from Www.Somanuals.com. All Manuals Search And Download.
SG SERIES GAS CONVECTION OVENS - REMOVAL AND REPLACEMENT OF PARTS
2. Remove the screws securing the ignitor and
flame sense to burner then remove the
assembly.
Fig. 22
Fig. 20
3. Reverse the procedure to install the assembly
and check for proper operation.
3. Disconnect the lead wires and igniter cable from
the ignition module board.
NOTE: Check to ensure the spark gap distance is
approximately 1/8". If the gap appears to be excessive
or poor sparking is occurring then adjust.
PREVIOUS PRODUCTION SHOWN
Fig. 21
4. Remove the ignition module board from the
mounting bracket.
5. Reverse the procedure to install the replacement
ignition module board.
CURRENT PRODUCTION SHOWN
SPARK IGNITER AND FLAME
SENSE
BLOWER AND MOTOR
Disconnect the
Disconnect the
electrical power to the machine and
follow lockout / tagout procedures.
electrical power to the machine and
follow lockout / tagout procedures.
SHUT OFF THE GAS BEFORE
SERVICING THE UNIT.
SHUT OFF THE GAS BEFORE
SERVICING THE UNIT.
1. Take out the racks and rack supports.
F45525 Rev. A (0315)
Page 12 of 33
Download from Www.Somanuals.com. All Manuals Search And Download.
SG SERIES GAS CONVECTION OVENS - REMOVAL AND REPLACEMENT OF PARTS
2. Remove screws securing the “snorkel” and
remove the snorkel.
5. Remove the screws securing the air baffle to the
rear wall at the lower right hand corner.
Fig. 27
Fig. 25
6. Remove the nuts that secure the motor mounting
plate to the rear wall.
3. Remove screws securing baffle panel and
remove the panel.
Fig. 28
Fig. 26
7. Place a piece of cardboard on the bottom of the
oven cavity to protect its surface from any
damage during motor assembly removal.
4. If replacing:
A. Blower Only - Loosen set screws on blower
hub and using a bearing puller, remove
blower from motor shaft.
8. Pull the motor assembly into the oven cavity and
place it on the cardboard.
1) Reverse procedure to install and adjust
blower position as outlined under
9. Remove the junction box cover from the motor,
disconnect lead wires and remove the conduit.
10. Remove motor mounting bolts and flat washers
then lift the motor from the mounting plate.
B. Motor - perform step 4A and continue
procedure.
Page 13 of 33
F45525 Rev. A (0315)
Download from Www.Somanuals.com. All Manuals Search And Download.
SG SERIES GAS CONVECTION OVENS - REMOVAL AND REPLACEMENT OF PARTS
11. Position the replacement motor on the motor
OVEN DOORS AND BEARINGS
mounting plate and install mounting bolts and
washers. Hand tighten mounting bolts only.
(INDEPENDENT DOORS)
12. Reconnect lead wires at the motor, replace
conduit and junction box cover.
Disconnect the
NOTE: Check data plate on motor for wiring
electrical power to the machine and
schematic. The motor must rotate clockwise when
follow lockout / tagout procedures.
viewed from the shaft end.
2. Remove the door switch lever.
Fig. 30
3. Remove the lower door seal strip to expose the
mounting screws of the door assembly.
4. Remove the two (2) lower sill bolts by the lower
door shaft and the four (4) counter-sunk screws
from the lower sill.
Fig. 29
13. Slide blower onto motor shaft until hub is flush
with end of shaft then tighten set screws.
14. Adjust motor position until blower is parallel to
motor mounting plate as outlined under
15. Position motor mounting plate on the rear wall
Fig. 31
and secure with nuts and washers.
NOTE: The door assembly is heavy and will drop
down once the last screw is removed. If removing door
assembly with-out assistance, the ignition cable,
flame sense lead and gas manifold should also be
removed to avoid damage to these components.
16. Replace the baffle panel and “snorkel”.
17. Replace the air baffle on the rear wall at the lower
right hand corner.
18. Remove cardboard from the bottom of the oven
cavity.
5. Tilt the top of the door slightly forward and lift the
door up until the bottom of the door shaft clears
the opening in the sill.
19. Install rack guides and racks.
20. Check oven for proper operation.
6. Lay the door flat to prevent damage.
7. The top and bottom bearings are now accessible
for inspection and/or replacement if needed.
A. If bearings are OK, proceed to step 8.
B. If replacing the top bearing, remove the top
bearing retainer and top bearing.
F45525 Rev. A (0315)
Page 14 of 33
Download from Www.Somanuals.com. All Manuals Search And Download.
SG SERIES GAS CONVECTION OVENS - REMOVAL AND REPLACEMENT OF PARTS
DOOR WINDOW
Disconnect the
electrical power to the machine and
follow lockout / tagout procedures.
1. Remove the screws at the top and bottom of
door.
Fig. 32
C. If replacing the bottom bearing, remove it
from the door shaft or the lower sill opening.
8. Reverse procedure to install door assembly and
check for proper adjustment as outlined under
ROLLER LATCH ASSEMBLY
(INDEPENDENT DOORS)
Fig. 34
Disconnect the
2. Independent doors:
electrical power to the machine and
follow lockout / tagout procedures.
A. Remove the door handle then remove the
outer door panel.
1. Remove the screws that attach roller latch
assembly to door.
B. Lift out the inner door panel and window
assembly.
NOTE: Left door only - remove door seal from the
inside edge of the door.
3. Simultaneous doors:
A. If replacing window on the left door, remove
the handle from the front of the door then
remove door seal from the inside edge of the
door.
1) Lift out the inner door panel and
window assembly.
2) If replacing window on the right door,
remove the screws along the inside
edge (if applicable) of the door then
remove the inner door panel and
window assembly.
Fig. 33
2. Reverse procedure to install.
4. Remove the screws securing the window “tabs”
to the door bracket and lift the window assembly
out from the door frame.
Page 15 of 33
F45525 Rev. A (0315)
Download from Www.Somanuals.com. All Manuals Search And Download.
SG SERIES GAS CONVECTION OVENS - REMOVAL AND REPLACEMENT OF PARTS
Fig. 36
4. Reverse procedure to install the replacement
switch and check for proper adjustment as
outlined under DOOR SWITCH ADJUSTMENT.
HIGH LIMIT THERMOSTAT
Disconnect the
electrical power to the machine and
follow lockout / tagout procedures.
1. Take out racks from the oven.
2. Remove the high limit thermostat cover/mounting
plate from inside the oven cavity at the top.
Fig. 35
5. Reverse procedure to install the replacement
window.
DOOR SWITCH
Disconnect the
electrical power to the machine and
follow lockout / tagout procedures.
2. Disconnect the lead wires to the door switch.
3. Remove the switch.
Fig. 37
3. Disconnect lead wires from high limit thermostat
then remove high limit thermostat from cover/
mounting plate.
F45525 Rev. A (0315)
Page 16 of 33
Download from Www.Somanuals.com. All Manuals Search And Download.
SG SERIES GAS CONVECTION OVENS - REMOVAL AND REPLACEMENT OF PARTS
1. Remove the lens and bulb.
2. Remove the springs from the retaining tabs (2
places) on the socket.
Fig. 38
NOTE: Remove the old RTV from the cover and
mating surfaces inside the oven cavity and apply new
RTV before installing.
Fig. 40
3. Depress the retaining tabs and pull the socket out
4. Reverse procedure to install.
from the oven, far enough to disconnect the lead
wires.
INTERIOR LIGHTS
4. Remove the socket from the oven.
5. Attach the lead wires to the replacement socket.
Disconnect the
6. Insert the socket into the hole in the oven and
electrical power to the machine and
push until the socket is held in place by the
follow lockout / tagout procedures.
retaining tabs.
7. Install the light bulb and lens.
Lamp
8. Check for proper operation.
1. Remove the racks.
2. Unscrew the glass lens for the light being
COOLING FAN
replaced then unscrew the bulb.
Disconnect the
electrical power to the machine and
follow lockout / tagout procedures.
NOTE: If right side panel is not accessible, this
component can be serviced by removing the
Fig. 39
2. Disconnect the lead wires to the fan motor by
removing wire nuts.
3. Replace bulb then reverse the procedure to
install.
3. Remove the screws securing the air deflector to
the fan then loosen the tab screw holding the fan
to the component panel. Rotate the tab so that
the fan will clear and remove the fan.
Disconnect the
electrical power to the machine and
follow lockout / tagout procedures.
Lamp Assembly
Page 17 of 33
F45525 Rev. A (0315)
Download from Www.Somanuals.com. All Manuals Search And Download.
SG SERIES GAS CONVECTION OVENS - REMOVAL AND REPLACEMENT OF PARTS
Fig. 41
4. Reverse the procedure to install the replacement
fan and check for proper operation.
NOTE: The fan must be installed so air is pulled from
the rear of the oven and blown into the control area.
The arrow on the fan body indicates “air flow” direction
and should be pointing toward the controls.
NOTE: Ensure fan is seated “squarely” against the air
tube and the oven bottom.
NOTE: The air deflector should be angled upwards
at approximately 30 degrees to properly direct the air
flow.
F45525 Rev. A (0315)
Page 18 of 33
Download from Www.Somanuals.com. All Manuals Search And Download.
SG SERIES GAS CONVECTION OVENS - SERVICE PRODCEDURES AND ADJUSTMENTS
SERVICE PRODCEDURES AND ADJUSTMENTS
Certain procedures in this section require electrical test or measurements while
power is applied to the machine. Exercise extreme caution at all times and follow Arc Flash
procedures. If test points are not easily accessible, disconnect power and follow Lockout/Tagout
procedures, attach test equipment and reapply power to test.
8. Calculate the average temperature by adding the
SOLID STATE TEMPERATURE
temperature indicated when the lamp goes out to
the temperature indicated when the lamp comes
on and dividing this answer by 2.
CONTROL CALIBRATION
1. Place a thermocouple in the geometric center of
[Temp. (lamp off) + Temp. (lamp on)] ÷ 2 =
Average Temp. Example: (360° + 340°) ÷ 2 =
the oven cavity.
350°
2. Set the ON-OFF-COOL DOWN switch to ON.
A. If the average temperature is less than 10°F
from the dial setting, the thermostat is
properly calibrated.
3. Set the NORMAL - GENTLE BAKE switch to
NORMAL.
4. Set the temperature control dial to 350°F.
B. If the average temperature is more than
10°F from the dial setting, the thermostat
calibration must be adjusted.
5. Allow the oven temperature to stabilize (normally
3 cycles).
6. Record the temperature at which the Heat lamp
goes OFF and comes ON for at least two
complete heating cycles.
1) Loosen the temperature control knob
set screw and remove the knob from
the stem.
7. Calculate the differential by subtracting the
temperature indicated when the lamp goes out
from the temperature indicated when the lamp
comes on.
2) Access the adjustment potentiometer
located at the 3 o'clock position.
a. Turn clockwise to increase,
counterclockwise to decrease
temperature
Differential = Heat lamp OFF - Heat lamp ON
Example: 360° (lamp off) - 340° (lamp on) =
20°
b. Repeat the average temperature
calculation in Step 8.
A. The differential calculated should be less
NOTE: Allow the oven to cycle at least two times
between adjustments before performing the
calculation.
than 20°F.
1) If the differential is less than 20°F, the
temperature control circuit is
functioning properly.
a) If the average temperature
still differs more than 10°F
from the dial setting, adjust
the thermostat calibration
until the average
2) If the differential is more than 20°F:
temperature is within
tolerance.
a. Check the temperature probe as
outlined under TEMPERATURE
C. If the above adjustment cannot be obtained,
replace the temperature control and check
calibration.
b. If the probe is functioning properly
then temperature control is
malfunctioning.
a) Install a replacement
temperature control and
check calibration.
Page 19 of 33
F45525 Rev. A (0315)
Download from Www.Somanuals.com. All Manuals Search And Download.
SG SERIES GAS CONVECTION OVENS - SERVICE PRODCEDURES AND ADJUSTMENTS
6. Check for proper voltage across terminals COM
SOLID STATE TEMPERATURE
AC to 120VAC or COM AC to 208-240VAC for
power to the control.
CONTROL TEST
A. If correct, proceed to step 7.
B. If incorrect, problem is not with the
Certain procedures in
temperature control. See
this section require electrical test or
measurements while power is applied
7. Check relay voltages on the board:
to the machine. Exercise extreme
caution at all times and follow Arc Flash
procedures. If test points are not easily
accessible, disconnect power and
follow Lockout/Tagout procedures,
attach test equipment and reapply
power to test.
A. For 120VAC controls - check across
OUTPUT RELAY terminal (left side) to
120VAC terminal for input to the internal
relay. Check across OUTPUT RELAY
terminal (right side) to 120 VAC for output
from the internal relay.
B. For 208-240VAC controls - check across
OUTPUT RELAY terminal (left side) to
208-240VAC terminal for input to the
internal relay. Check across OUTPUT
RELAY terminal (right side) to 208-240VAC
for output from the internal relay.
NOTE: If right side panel is not accessible, this
component can be serviced by removing CONTROL
2. Place a thermocouple in the geometric center of
the oven cavity.
1) If input voltage to the internal relay is
correct, proceed to step 8. If input
voltage to the internal relay is not
present, problem is not with the
temperature control. See
NOTE: Oven temperature must be below 450°F.
NOTE: If oven is equipped with "Cook and Hold"
option, set to Cook (normal cooking) before
continuing.
3. Set the temperature control to the maximum
setting.
2) If output voltage from the internal relay
is correct proceed to step 8. If output
voltage from the internal relay is not
correct, check temperature probe as
outlined under TEMPERATURE
4. Check machine data plate for correct voltage to
oven. Refer to diagram below for proper terminal
locations and voltages before checking the
control. Use the correct terminals for the
corresponding voltage.
8. Set the temperature control to the minimum
setting.
5. Turn the power switch to ON.
NOTE: Oven temperature must be above 300°F.
9. Check for zero (0) volts AC across terminals
OUTPUT RELAY terminal (right side) to 120VAC
or OUTPUT RELAY terminal (right side) to
208-240VAC for no output from the internal relay.
A. If correct, temperature control is functioning
properly.
B. If incorrect, check temperature probe as
outlined under TEMPERATURE PROBE
1) If temperature probe is OK:
a. Turn the power switch OFF.
Fig. 42
F45525 Rev. A (0315)
Page 20 of 33
Download from Www.Somanuals.com. All Manuals Search And Download.
SG SERIES GAS CONVECTION OVENS - SERVICE PRODCEDURES AND ADJUSTMENTS
TEMP (°F)
320
OHMS*
1,332
TEMP (°F)
OHMS*
Disconnect the
475
266
electrical power to the machine and
follow lockout / tagout procedures.
340
1,041
(*) Resistance in ohms ± 10%
b. Replace the temperature control
and check calibration as outlined
under SOILD STATE
GAS VALVE PRESSURE CHECK
Disconnect the
electrical power to the machine and
follow lockout / tagout procedures.
TEMPERATURE PROBE TEST
1. Turn gas supply off at manual shutoff valve.
Disconnect the
electrical power to the machine and
follow lockout / tagout procedures.
NOTE: If right side panel is not accessible, this
component can be serviced by removing the
NOTE: The temperature probe used in conjunction
with the Solid State Temperature control is an RTD
(resistance temperature detector) of the Thermistor
type. As temperature increases the resistance value
decreases.
3. Remove the plug from the manifold pressure
port.
NOTE: If right side panel is not accessible, this
component can be serviced by removing the
2. Place a shielded thermocouple in the geometric
center of the oven cavity and determine the
temperature in the oven cavity.
3. Remove the probe lead wires from the solid state
temperature control.
4. Test the probe with an ohmmeter.
A. If the measured resistance values are inside
the given tolerance then the probe is
functioning properly.
B. If the measured resistance values are
outside the given tolerance then replace the
probe and retest.
Fig. 43
4. Install hose barb adapter and attach manometer
tube.
1) Check oven for proper operation.
5. Reverse procedure to install.
5. Turn gas supply to the oven back on.
6. Plug the unit in and turn the power switch ON.
TEMP (°F)
77
OHMS*
90,000
4,077
3,016
2,266
1,726
TEMP (°F)
360
OHMS*
822
7. Set the temperature control to its highest setting
and allow burner to ignite.
240
380
656
NOTE: The burner must be lit during test.
260
400
529
NOTE: Accurate gas pressure readings can only be
made with the gas on and the burner lit.
280
425
424
300
450
334
Page 21 of 33
F45525 Rev. A (0315)
Download from Www.Somanuals.com. All Manuals Search And Download.
SG SERIES GAS CONVECTION OVENS - SERVICE PRODCEDURES AND ADJUSTMENTS
PRESSURE READINGS (IN W.C.)
GAS TYPE
LINE
MANIFOLD
RECOMMENDED
MIN
6.0
MAX
Natural
5.0
8.0
14.0
Propane
10.0
11.0
11.0
NOTE: If the incoming line pressure to the valve is less than the minimum stated, then the manifold pressure will
not be maintained
VERIFICATION OF SPARK AT
IGNITOR
Disconnect the
electrical power to the machine and
follow lockout / tagout procedures.
SHUT OFF THE GAS BEFORE
Fig. 45
SERVICING THE UNIT.
4. Plug the oven in and set the temperature control
to the maximum setting.
2. Disconnect the high voltage "ignition cable" from
the spark ignitor.
5. Turn the power switch ON.
6. Sparking should occur after a 4 second delay, for
a duration of 7 seconds then repeat twice after a
15 second purge time. Arching from the ignition
cable to the oven frame should be observed.
DOOR SWITCH ADJUSTMENT
Disconnect the
electrical power to the machine and
follow lockout / tagout procedures.
2. Door operation:
Fig. 44
DO NOT HOLD THE WIRE WITH
A. Independent doors - The switch actuator
should be operated by the switch lever when
the right door is between 1" and 1 ½" from
being closed.
YOUR HANDS FOR THIS TEST. THE MANUAL GAS
VALVE MUST BE CLOSED.
3. Clamp the ignition cable in a manner that will
position the end of the cable 3/16" from the oven
frame (bare metal surface).
B. Simultaneous doors - The switch actuator
should be operated by the switch lever when
the right door is ½" from being closed.
NOTE: It is critical that the cable be held 3/16" away
from the surface of the oven frame or sparking may
not occur even though the sparking circuit is
functioning properly.
3. If adjustment is necessary, bend the switch
actuator to obtain the proper setting.
F45525 Rev. A (0315)
Page 22 of 33
Download from Www.Somanuals.com. All Manuals Search And Download.
SG SERIES GAS CONVECTION OVENS - SERVICE PRODCEDURES AND ADJUSTMENTS
Fig. 46
Fig. 47
4. Install the top front cover.
4. Reverse the procedure to install.
5. Apply power to the oven and check for proper
operation.
DOOR ADJUSTMENT
BLOWER ADJUSTMENT
Disconnect the
electrical power to the machine and
follow lockout / tagout procedures.
Disconnect the
electrical power to the machine and
follow lockout / tagout procedures.
1. Check the doors to make sure they have an equal
gap between them and that the vertical edge of
the door is parallel to the vertical door seal. If the
doors are not positioned in this manner, adjust
the doors as described.
SHUT OFF THE GAS BEFORE
SERVICING THE UNIT.
1. Remove the blower motor and mounting
assembly by following steps 1 through 8 as
outlined under BLOWER AND MOTOR.
2. Loosen the motor mounting bolts.
3. Adjust the motor position until the blower is
parallel to and 1/4 inch away from the motor
mounting plate. Check for squareness of the
blower to the motor mounting plate at the top,
bottom, left and right of the blower.
A. If the blower is square then tighten motor
mounting bolts and proceed to Step 4.
B. If the blower is not square continue
adjusting until proper spacing is achieved
then tighten motor mounting bolts.
NOTE: If necessary, place shims between motor and
frame.
Page 23 of 33
F45525 Rev. A (0315)
Download from Www.Somanuals.com. All Manuals Search And Download.
SG SERIES GAS CONVECTION OVENS - SERVICE PRODCEDURES AND ADJUSTMENTS
4. Move the door until proper alignment is achieved
then tighten the screws on the upper door
bearing hardware.
necessary.
DOOR STRIKE ADJUSTMENT
(INDEPENDENT DOORS)
NOTE: For units with serial number starting with 48
made after 8/12/07 and serial number starting with 54
made after 8/26/07.
Disconnect the
electrical power to the machine and
follow lockout / tagout procedures.
2. Open the doors and inspect door strike for proper
shape.
A. Replace if bent. Do not bend strike plate.
B. If adjustment is necessary, loosen
fasteners, close doors and insure contact
between door inner surface and upper
horizontal seal. Slide door strike plate until
contact with roller latch is made. Tighten
strike plate fasteners.
Fig. 48
3. Loosen the screws that secure the upper door
bearings and related hardware, just enough to
allow door movement.
Fig. 50
3. Open and close the doors several times while
observing the roller latch and strike plate
operation.
A. Replace roller latch if malfunctioning as
outlined under ROLLER LATCH
Fig. 49
and adjust as outlined in this procedure.
F45525 Rev. A (0315)
Page 24 of 33
Download from Www.Somanuals.com. All Manuals Search And Download.
SG SERIES GAS CONVECTION OVENS - SERVICE PRODCEDURES AND ADJUSTMENTS
4. Each oven door should open with a force of 8 to
25 pounds when pulled at the handle. The
adjustments must allow the doors to remain
closed during normal operation and allow
opening without exertion by the user.
Page 25 of 33
F45525 Rev. A (0315)
Download from Www.Somanuals.com. All Manuals Search And Download.
SG SERIES GAS CONVECTION OVENS - ELECTRICAL OPERATION
ELECTRICAL OPERATION
COMPONENT FUNCTION
Power Switch (S1) . . . Determines the mode of operation; ON, OFF, or COOL DOWN.
Oven Light Switch (S2) Controls the oven cavity lights.
. . . . . . . . . . . . . . . . . . . . . . . .
Fan Speed Switch Hi/
Controls blower motor speed between Hi and Low settings.
Low (S3) . . . . . . . . . . . . .
Bake Mode Switch (S4) Selects the cooking mode of the oven between Normal and Gentle Bake. Controls call
. . . . . . . . . . . . . . . . . . . . . . . . for heat 100% for Normal 75% for Gentle Bake.
Buzzer . . . . . . . . . . . . . . . Signals the end of a cook cycle.
Timer . . . . . . . . . . . . . . . . . Counts the time of the product and signals the buzzer at the end of the cycle.
Door Switch . . . . . . . . . . Allows the oven to operate when the doors are closed but stops the oven from operating
when the doors are opened.
Blower Motor . . . . . . . . Operates the oven cavity blower (convection fan). Also, an internal centrifugal switch on
the motor is utilized to allow the connection of power to the heat relay (R3) when the
motor is at operating speed.
Transformer (T1) . . . . . Provides 24VAC power to the ignition control module and heating circuit.
Solid State
Monitors temperature sensor and regulates the oven cavity temperature by controlling
Temperature Control . . . the heat relay (R3) through the blower motor centrifugal switch contacts.
High Limit Thermostat . . .Protects the oven from temperatures above 550°F by removing power from the 1st valve
(safety) on the dual solenoid gas valve which stops the flow of gas to the burner. Auto
resets at 500°F.
Ignition Control
Controls the gas ignition cycle - Energizes the 2nd valve (main) on the dual solenoid gas
Module . . . . . . . . . . . . . . . valve, generates spark for burner ignition, monitors the presence of a flame and controls
the No Ignition light. The ignition times are: 4 second self diagnostic test (initial power
ON); 7 second ignition trial; 3 ignition trials with a 15 second purge between each trial.
Igniter/Flame Sense . . . Ignites the gas and senses the presence of a flame. The flame presence generates a
micro-amp "flame sense" current that is monitored by the ignition control module. A flame
sense current of 1.0 micro amp (minimum) is required to maintain burner ignition.
Power On Light . . . . . . Lit whenever the power switch (S1) is turned to ON or Cool Down mode.
Heat Light . . . . . . . . . . . . Lit whenever temperature control is calling for heat.
No Ignition Light . . . . . Lit when power is turned ON, during ignition trial & gas purge time and when no flame is
detected by flame sensor. If the oven fails to ignite after 3 attempts, it will remain lit until
power is reset.
Temperature Probe . . . Senses the oven temperature for the solid state temperature control. Converts the
temperature into a resistance valve which is monitored by the temperature control board.
The probe is an RTD (resistance temperature detector) of the Thermistor type. As
temperature increases the resistance value decreases.
Gas Valve (Dual
Allows gas flow to the burner when the 1st valve (safety) and 2nd valve (main) solenoid
Solenoid) . . . . . . . . . . . . . coils are both energized.
Cooling Fan . . . . . . . . . . Circulates cooler air from rear of oven forward to cool components in the control area.
F45525 Rev. A (0315)
Page 26 of 33
Download from Www.Somanuals.com. All Manuals Search And Download.
SG SERIES GAS CONVECTION OVENS - ELECTRICAL OPERATION
A. Oven connected to correct voltage.
1) L1 (HOT) to power switch (S1).
a. Power (24VAC) to one side of the
following components: heat relay
(R3) normally open (N.O.)
contacts, high limit --- connected
through the normally closed
(N.C.) contacts to the 1st valve
(safety) on the dual solenoid gas
valve.
2) L2 (NEUTRAL or SECOND LINE) to
one side of the following components:
power ON light, heat light, temperature
control board terminal T2 (120VAC) or
terminal T3 (208- 240VAC), oven
cavity lights, buzzer, "Cook" timer
motor, heat relay coil (R3), convection
fan motor common ©), transformer
primary (T1), motor speed (Hi/Low)
switch and the component cooling fan.
a) 1st valve (safety) on the gas
valve energized.
NOTE: Gas does not flow to the burner until the 2nd
valve (main) is energized.
B. Oven properly grounded.
C. Gas supply valve ON.
2) With door switch closed, power is
applied to motor speed switch (Hi/
Low).
D. Gas combination control valve ON.
E. Power switch (S1) OFF.
a. When the convection fan motor
reaches operating speed, the
centrifugal switch (N.O.) on the
motor closes.
F. Oven light switch (S2) ON/OFF (position
has no affect on the function of the "Cook"
cycle).
b. Power to normally open (N.O.)
side of internal relay contacts
(terminal 7) on the temperature
control board.
G. Temperature control dial set to lowest
temperature (fully counterclockwise).
H. High limit switch CLOSED.
3) Power is also connected back through
a second set of contacts on the power
switch (S1) to terminal 8 on the
I.
Timer in the OFF position.
J. Oven doors Closed.
temperature control board.
1) Door switch contacts CLOSED.
K. Oven cavity temperature below 140°F.
a. Solid state temperature control
energized. If the oven
temperature is below set point,
the temperature control will
energize its internal relay. The
normally open (N.O.) contacts
close and apply power to the
following components:
2. Set temperature control dial to desired
temperature.
3. Power switch (S1) turned ON.
A. Component cooling fan energized.
B. Power ON light (Amber) comes ON.
a) Heat light (clear) comes ON.
C. Power to one side of the following
components: Timer terminal 1, transformer
primary (T1).
b) Power is connected through
the centrifugal switch
contacts on the convection
fan motor, heat relay (R3) is
energized, (R3) contacts
(N.O.) close and the heating
circuit is powered.
NOTE: Power is available to the oven light switch
(wire #20) to turn the oven cavity lights ON when the
light switch is turned ON; and power is available to the
normally open N.O. side (wire #28) of the door switch
contacts and connects power to additional
components when the door switch contacts are
CLOSED (door closed).
c) Ignition control module is
energized.
1) Transformer (T1) energized.
Page 29 of 33
F45525 Rev. A (0315)
Download from Www.Somanuals.com. All Manuals Search And Download.
SG SERIES GAS CONVECTION OVENS - ELECTRICAL OPERATION
d) No ignition light (red) comes
ON, module performs a self
diagnostic test for 4 seconds,
2nd valve (main) on the gas
valve is energized. Gas
B. Oven cavity temperature needs to be
lowered.
C. Doors are open.
1) Door switch contacts OPEN
D. Cook timer in the OFF position.
2. Power Switch (S1) turned to COOL DOWN.
starts to flow to the burner,
sparking begins, the "no
ignition" light goes out and
burner lights. Sparking
continues for up to 7 seconds
or until a flame is
established. If a flame is
"sensed", the "no ignition"
light stays out and burner
remains lit. If a flame is not
"sensed" after 7 seconds of
sparking, the "no ignition"
light comes back on, 2nd
valve (main) on the gas valve
is de-energize and gas flow
to the burner stops. Ignition
trial cycle repeats after a 15
second purge between
NOTE: With door switch contacts OPEN (doors
open), the convection fan motor will still run and
continue to cool the oven. However, power would be
removed from the following components: Power ON
light (goes out), transformer T1 (de-energized) and to
the component cooling fan.
A. Power to motor speed switch (Hi/Low).
1) Motor speed (Hi/Low) relay (R1) is
energized and contacts change state.
a. Convection fan motor energized.
b. When Convection fan motor
reaches operating speed the
centrifugal switch on the motor
closes but no power is available
for connection to other
cycles for two additional tries
before locking out. To reset
after a lockout, turn power
switch (S1) OFF then ON.
components.
3. If door switch is CLOSED (doors closed), power
is supplied to one side of the following
4. Oven reaches set temperature.
A. Temperature control de-energizes internal
relay and the normally open (N.O.) contacts
OPEN.
components: Power ON light (Amber), oven light
switch (S2), timer terminal 1, transformer primary
(T1) and component cooling fan.
1) Heat light goes out.
A. Power ON light (Amber) comes ON.
B. Transformer (T1) energized.
2) Power removed from heat relay (R3).
a. R3 normally open (N.O.) contacts
OPEN.
1) Power (24VAC) to one side of the
following components: heat relay (R3)
normally open (N.O.) contacts, high
limit --- connected through the normally
closed (N.C.) contacts to the 1st valve
(safety) on the dual solenoid gas valve.
a) Power removed from 2nd
valve (main) on the gas valve
and gas flow to the burner
stops.
a. 1st valve (safety) on the gas valve
energized.
5. The oven will continue to cycle on the
temperature control until the doors are opened or
power switch (S1) is turned to the OFF or COOL
DOWN position.
NOTE: Gas does not flow to the burner until the 2nd
valve (main) is energized.
Cool Down Cycle (Solid State Temperature
Control)
4. The oven will remain in this condition until the
power switch (S1) is turned to the OFF or ON
position.
1. Conditions.
A. Oven is ON.
F45525 Rev. A (0315)
Page 30 of 33
Download from Www.Somanuals.com. All Manuals Search And Download.
SG SERIES GAS CONVECTION OVENS - TROUBLESHOOTING
TROUBLESHOOTING
Certain procedures in this section require electrical test or measurements while
power is applied to the machine. Exercise extreme caution at all times and follow Arc Flash
procedures. If test points are not easily accessible, disconnect power and follow Lockout/Tagout
procedures, attach test equipment and reapply power to test.
ALL MODELS
SYMPTOMS
POSSIBLE CAUSES
1. Line voltage.
2. Power switch (S1) malfunction.
Blower motor doesn’t run with 1S in “Cool Down” or “On”
position.
3. Switch (S3) malfunction.
4. Interconnecting wiring malfunction.
5. Motor inoperable.
1. Door switch malfunction.
Blower motor doesn’t run in “On” position. “Cool Down”
functions OK.
2. Power switch contacts inoperative.
3. Interconnecting wiring malfunction.
1. Power switch malfunction.
Blower motor doesn’t run in “Cool Down” position. Runs
OK in “On” position.
2. Interconnecting wiring malfunction.
1. Shorted electrode on ignitor/flame sense.
2. Ignitor cable (high voltage) OPEN.
3. Heat relay (R3) malfunction.
Gas does not ignite; No spark; No Ignition Light ON.
4. Transformer (T1) inoperative.
5. High limit thermostat open.
6. Interconnecting wiring malfunction.
7. Ignition Module malfunction.
1. Gas solenoid valve OFF or inoperative.
2. Manual gas valve CLOSED.
Sparks but gas does not ignite.
3. Gas supply OFF or Insufficient gas pressure.
4. Interconnecting wiring malfunction.
5. Ignition Module malfunction.
1. Igniter lead connections malfunction.
2. Ignitor ground inoperative.
3. Ignitor/flame sense malfunction.
4. Insufficient gas pressure.
Gas ignites but will not maintain flame.
5. Snorkel vent plugged, obstructed or missing.
6. Incorrect polarity from transformer (T1) to Ignition
module.
F45525 Rev. A (0315)
Page 32 of 33
Download from Www.Somanuals.com. All Manuals Search And Download.
SG SERIES GAS CONVECTION OVENS - TROUBLESHOOTING
SYMPTOMS
POSSIBLE CAUSES
1. Temperature probe malfunction.
2. Temperature control board malfunction.
3. Gas pressure Insufficient.
Excessive or low heat.
4. Gas orifice plugged or obstructed.
1. Interconnecting wiring malfunction.
Mechanical Timer inoperative or not functioning properly. 2. Line voltage incorrect.
3. Timer malfunction.
1. Motor inoperable.
Component cooling Fan does not run.
2. Interconnecting wiring malfunction.
1. Convection Fan motor speed/direction.
2. Poor combustion.
A. Gas pressure incorrect.
Uneven Cooking.
B. Exhaust vent plugged or obstructed.
C. Snorkel Vent plugged or obstructed.
3. Air flow Baffles missing or damaged.
1. High ambient temperatures.
2. Wiring connections loose.
Intermittent problems.
3. Cooling fan malfunction.
1. Power switch (S1) in “Cool Down”.
2. Door or door switch open.
No power to temperature control.
Page 33 of 33
F45525 Rev. A (0315)
Download from Www.Somanuals.com. All Manuals Search And Download.
|