38TRA
Air Conditioning Unit
Installation and Start-Up Instructions
NOTE: Read the entire instruction manual before starting the
installation.
SAFETY CONSIDERATIONS
Improper installation, adjustment, alteration, service, maintenance,
or use can cause explosion, fire, electrical shock, or other
conditions which may cause personal injury or property damage.
Consult a qualified installer, service agency, or your distributor or
branch for information or assistance. The qualified installer or
agency must use factory-authorized kits or accessories when
modifying this product. Refer to the individual instructions pack-
aged with the kits or accessories when installing.
Follow all safety codes. Wear safety glasses and work gloves. Use
quenching cloth for brazing operations. Have fire extinguisher
available. Read these instructions thoroughly and follow all
warnings or cautions attached to the unit. Consult local building
codes and the National Electrical Code (NEC) for special instal-
lation requirements.
Recognize safety information. This is the safety-alert symbol
.
When you see this symbol on the unit or in instructions and
manuals, be alert to the potential for personal injury.
Understand the signal word DANGER, WARNING, or CAU-
TION. These words are used with the safety-alert symbol. DAN-
GER identifies the most serious hazards which will result in severe
personal injury or death. WARNING signifies hazards that could
result in personal injury or death. CAUTION is used to identify
unsafe practices which would result in minor personal injury or
product and property damage.
A92446
Fig. 1—Model 38TRA
clearance on 1 side of unit and 12 in. on all remaining sides must
be maintained. Maintain a distance of 24 in. between air condi-
tioners. Position so snow, ice, and water from roof or eaves cannot
fall directly on unit.
On rooftop applications, locate unit at least 6 in. above roof
surface. Where possible, place unit above a load-bearing wall.
Before installing or servicing system, always turn off main
power to system. There may be more than 1 disconnect
switch. Turn off accessory heater power if applicable. Elec-
trical shock can cause personal injury or death.
Arrange supporting members to adequately support unit and
minimize transmission of vibration to building. Consult local
codes governing rooftop applications.
Step 3—Replace Indoor AccuRater® Piston, If Required
INSTALLATION
Check indoor coil piston to see if it matches the required piston
shown on unit rating plate. (See Fig. 2.) If it does not match,
replace indoor coil piston with piston shipped with this unit. The
piston shipped with outdoor unit is correct for any approved indoor
coil combination.
Step 1—Check Equipment and Jobsite
UNPACK UNIT — Move to final location. Remove carton taking
care not to damage unit.
INSPECT EQUIPMENT — File claim with shipping company,
prior to installation, if shipment is damaged or incomplete. Locate
unit rating plate on unit corner panel. (See Fig. 2.) It contains
information needed to properly install unit. Check rating plate to
be sure unit matches job specifications.
If unit is to be installed on system with a thermostatic
expansion valve (TXV), removal of the indoor coil piston is
required.
Step 2—Install on a Solid, Level Mounting Pad
If conditions or local codes require the unit be attached to pad,
tiedown bolts should be used and fastened through knockouts
provided in unit base pan. Refer to unit mounting pattern in Fig. 2
to determine base pan size and knockout hole location.
When installing, allow sufficient space for airflow clearance,
wiring, refrigerant piping, and service. Allow 30-in. clearance to
service end of unit and 48 in. above unit. For proper airflow, a 6-in.
Manufacturer reserves the right to discontinue, or change at any time, specifications or designs without notice and without incurring obligations.
Book
Tab 3a 2a
1
4
PC 101
Catalog No. 563-793
Printed in U.S.A.
Form 38TRA-3SI
Pg 1
1-94
Replaces: 38TRA-2SI
INSTALL SOLENOID VALVE IN LIQUID TUBE
NOTE:
AVOID CONTACT BETWEEN TUBING AND STRUCTURE
INDOOR WALL
Solenoid valve must be energized during evacuation for
effective evacuation.
OUTDOOR WALL
CAULK
Before making liquid tube connections, install factory-supplied
solenoid valve on indoor liquid fitting. (See Fig. 4.) Be sure to use
flare adapter supplied with the indoor coil when making connec-
tions.
INSULATION
If a field-supplied control power source is needed when
adding solenoid, wiring must comply with local codes and
NEC requirements.
VAPOR LINE
LIQUID LINE
THROUGH THE WALL
1. Remove coil liquid connection cap and discard.
2. Mount solenoid valve on liquid tube, making sure valve flow
arrow points toward indoor coil. Mount valve in any position
except valve body at top and electric coil at bottom. (See Fig.
4.) The solenoid valve is to be installed a maximum of 24 in.
from indoor coil.
JOIST
HANGER STRAP
(AROUND VAPOR
LINE ONLY)
VAPOR LINE
3. Braze valve onto end of liquid tube using silver bearing or
non-silver bearing brazing material. Consult local code re-
quirements.
4. Braze flare adapter onto outlet end of the solenoid valve.
5. Wire solenoid coil into system control circuit as shown in Fig.
6.
Table 1—Refrigerant Connections and Recom-
mended Liquid and Vapor Tube Diameters (In.)
INSULATION
1″
MIN
LIQUID
LINE
LIQUID
Connect
VAPOR
Connect
UNIT
SIZE
Tube
Tube
SUSPENSION
Diameter
Diameter
Diameter
Diameter
018, 024
030, 036
042, 048
060
3/8
3/8
3/8
3/8
3/8
5/8
5/8
3/4
A92469
3/8
3/4
Fig. 3—Piping Installation
3/8
7/8
7/8
3/8
7/8
1-1/8
ELECTRICAL JUNCTION
ELECTRICAL COIL
Notes: 1. Tube diameters are for lengths up to 50 ft. For tubing lengths greater
than 50 ft, consult Long-Line Application Guideline.
2. Do not apply capillary-tube indoor coils to these units.
REFRIGERANT TUBING — Connect tubing to fittings on out-
door unit vapor and liquid service valves. (See Fig. 2.)
A brazing shield MUST be used when tubing sets are being
brazed to the service valves to prevent damage to the painted
unit surface.
Relieve pressure and recover all refrigerant before system
repair or final unit disposal to avoid personal injury or death.
Use all service ports and open all flow control devices,
including solenoid valves.
VALVE
FLOW ARROW
3
STRAIGHT
/
IN. STUD
8
NOTE:System flow direction
must match arrow on
bottom of body.
A87044
Fig. 4—Solenoid Valve Installation
To avoid valve damage while brazing, service valves must be
wrapped with a heat-sinking material such as a wet cloth.
connected by 15 ft of field-supplied or factory-accessory tubing.
Check refrigerant charge for maximum efficiency. (See Step
8—Checking Charge.)
SWEAT CONNECTION — Use refrigerant grade tubing. Service
valves are closed from factory and ready for brazing. After
wrapping the service valve with a wet cloth, the tubing set can be
brazed to the service valve using either silver bearing or non-silver
3
bearing brazing material. Consult local code requirements. Refrig-
erant tubing and indoor coil are now ready for leak testing. This
check should include all field and factory joints.
Use No. 18 AWG color-coded, insulated (35° C minimum) wire.
If thermostat is located more than 100 ft from unit (as measured
along the control voltage wires), use No. 16 AWG color-coded
wire to avoid excessive voltage drop.
Step 5—Make Electrical Connections
Use furnace transformer, fan coil transformer, or accessory trans-
former for control power, 24-v/40va minimum.
Be sure field wiring complies with local and national fire, safety,
and electrical codes, and voltage to system is within limits shown
on unit rating plate. Contact local power company for correction of
improper voltage. See unit rating plate for recommended circuit
protection device. (See Fig. 2.)
NOTE: Use of available 24-v accessories may exceed the mini-
mum 40-va power requirement. Determine total transformer load-
ing and increase the transformer capacity or split the load with an
accessory transformer as required.
Step 6—Install Electrical Accessories
NOTE: Operation of unit on improper line voltage constitutes
abuse and could affect unit reliability. See unit rating plate.
Refer to the individual instructions packaged with the kits or
accessories when installing.
NOTE: Use only copper wire between disconnect switch and
unit.
Step 7—Start-up
1. Fully back seat (open) liquid and vapor service valves.
NOTE: Install branch circuit disconnect per NEC of adequate
size to handle unit starting current, but not larger than maximum
fuse size shown on unit rating plate. Locate disconnect within sight
from and readily accessible from unit, per Section 440-14 of NEC.
2. Unit is shipped with valve stem(s) front seated and caps
installed. Replace stem caps after system is opened to refrig-
erant flow (back seated). Replace caps finger tight and tighten
additional 1/6 turn with wrench.
ROUTE GROUND AND POWER WIRES — Remove access
panel and control box cover to gain access to unit wiring. Extend
wires from disconnect through power wiring hole provided and
into unit control box. (See Fig. 2.) Size wires per NEC but not
smaller than minimum wire size shown in presale literature.
3. Close electrical disconnects to energize system.
4. Set room thermostat at desired temperature. Be sure set point
is below indoor ambient temperature.
5. Set room thermostat at COOL and fan switch at FAN or
AUTO, as desired. Operate unit for 15 minutes. Check system
refrigerant charge. (See Step 8—Checking Charge.)
Step 8—Checking Charge
The cabinet must have an uninterrupted or unbroken ground
according to NEC, ANSI/NFPA 70-1993 or local codes to
minimize personal injury if an electrical fault should occur.
This may consist of electrical wire or conduit approved for
electrical ground when installed in accordance with existing
electrical codes. Failure to follow this warning could result in
an electrical shock, fire, or death.
Factory charge is shown on unit rating plate. (See Fig. 2.)
Do not disable low-pressure switch during a condenser pump
down. Compressor damage may occur if run at a negative
suction pressure.
Compressor damage may occur if system is overcharged.
To avoid personal injury or death, do not supply power to unit
with compressor terminal box cover removed.
Service valve gage ports are not equipped with Schrader
valves. To prevent personal injury, make sure valves are fully
back seated before removing gage port caps. Wear safety
glasses and gloves when handling refrigerant.
CONNECT GROUND AND POWER WIRES — Connect ground
wire to ground connection in control box for safety. Connect
power wiring to contactor as shown in Fig. 5.
DISCONNECT
PER N. E. C. AND/OR
LOCAL CODES
Adjust charge by following procedure shown on the superheat
charging tables located on unit information plate.
CONTACTOR
FIELD POWER
WIRING
Do not vent refrigerant to atmosphere. Recover during system
repair or final unit disposal.
CARE AND MAINTENANCE
FIELD GROUND
For continuing high performance and to minimize possible equip-
ment failure, it is essential that periodic maintenance be performed
on this equipment. Consult your servicing contractor or User’s
Manual for the proper frequency of maintenance. Frequency of
maintenance may vary depending upon geographic areas, such as
coastal applications.
WIRING
GROUND
LUG
A91056
Fig. 5—Line Power Connections
Step 1—Leave User’s Manual With Homeowner
CONNECT CONTROL WIRING — Route 24-v control wires
through control wiring grommet and connect to brown and blue
pigtails supplied in unit splice box. (See Fig. 6.)
Explain system operation and maintenance procedures outlined in
User’s Manual.
4
TRANS
SEE NOTE 2
THERMOSTAT
SUBASE
TRANS
MIN 60VA
4
RH
RC
B
LEAVE JUMPER
ON SUBASE
(RH TO RC)
R
LLS
NC
LLS
NC
Y1
Y2
Y
TO IFM LINE
Y
C
TO IFM LINE
VOLTAGE
POWER
VOLTAGE
POWER
SUPPLY
C
BLU
BRN
C
BLU
COND UNIT
BRN
SUPPLY
G
G
A
IFR
IFR
W1
W2
HC
1
HC
2
W
ARRANGEMENT A–COOLING ONLY
TRANS
ARRANGEMENT C–1 TRANSFORMER;
COOLING AND 2-STAGE HEATING
:
NOTES 1. REFER TO UNIT LABEL WIRING DIAGRAM FOR
WIRE COLORS. IFR, IFM AND LLS ARE LOCATED
INDOORS ON HEATING-COOLING APPLICATIONS.
IF ACCESSORY IFR IS REQUIRED FOR COOLING-
ONLY APPLICATIONS, LOCATE IFR IN FAN COIL.
SEE NOTE 2
4
ADD JUMPER
R
LLS
NC
2. N.E.C. CLASS 2, 24V CIRCUIT, MIN 40VA REQUIRED.
– CONTACTOR
C
Y
HC
IFM
LLS
NC
– HEATING CONTROL
– INDOOR FAN MOTOR
– LIQUID LINE SOLENOID VALVE
– NORMALLY CLOSED
TO IFM LINE
VOLTAGE
POWER
SUPPLY
C
TRANS – TRANSFORMER
BLU
BRN
G
A
IFR
W
HC
ARRANGEMENT B – 1 TRANSFORMER;
COOLING AND 1-STAGE HEATING
A93199
Fig. 6—24-V Control Circuit Connector
5
Copyright 1993 CARRIER Corp. • 7310 W. Morris St. • Indianapolis, IN 46231
33026c
Manufacturer reserves the right to discontinue, or change at any time, specifications or designs without notice and without incurring obligations.
Book
Tab 3a 2a
1
4
PC 101
Catalog No. 563-793
Printed in U.S.A.
Form 38TRA-3SI
Pg 6
1-94
Replaces: 38TRA-2SI
|