Carrier 38EV024320 - Manual (Page 41)

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OUTDOOR FAN/MOTOR REMOVAL—
Make sure power is off to indoor and outdoor units.
9. Remove fan/motor/orifice assembly by removing
remaining 4 screws around orifice assembly. (If control
box is not being removed, remove safety shield, and (2)
screws in upper control box). See Warning, above.
Unplug motor wires from base of motor prior to lifting out
assembly.
Remove Coil—
À WARNING
Cutting tubing is recommended to avoid possibility of
fire, and personal injury.
10
11 .
Use midget tubing cutter to cut liquid and vapor lines
at either side of coil. Cut in convenient location for easy
reassembly with copper slip couplings.
Remove 4 screws around base pan securing louvered
casing and wire coil wrap. Set louvered casing aside.
12. Lift coil vertically off base pan and place carefully to
one side.
NOTE: While coil is removed from unit for intended service,
use this opportunity to remove and replace strainer.
COMPRESSOR REPLACEMENT
A CAUTION
Check whether
tiedown bolts/
unit is fastened to platform with
1. Remove control box, fan and coil as described under
“CoU Removal” above.
2. Disconnect electrical leads from compressor.
Compressor is Srphase—Note lead locations for proper
wiring of replacement compressor.
Wire
Marking Color
-024 Models: T1 — Black
..... :T2~WeUbw...... .
T3 — Blue
-036 Models: U — Black
V —Yellow
W -Blue
3. Cut compressor suction and discharge tubes at conven­
ient location.
4. Loosen and remove crankcase heater (-036 models
only).,/ /
5. Remove compressor mounting bolts.
6. Lift compressor out.
7. Carefully unbraze suction and discharge fine piping
stubs frora compressor. Note position of stubs to assist
when reinstalling.
8. Install new compressor. Install crankcase heater
around compressor (-036 models only). Install compres­
sor mounting bolis.
9. Braze suction and discharge fines to compressor (where
unbrazed in Step 7) and piping stubs (at point where
cut in Step 3 above). Rewire compressor.
10. Replace coil,;braze liquid and vapor line. Test for leaks.
11. Replace fan/motor/orifice assembly.
12. Replace control box and reconnect wiring., (See note
above, under “Control Box Removal.”)
13. Evacuate and recharge system
INSTALL FILTER DRIER-Install field-supplied heat
pump filter drier in system liquid fine when refrigerant sys­
tem is opened for service as described under “Compressor
Replacement,” above. Position drier in liquid fine at conven­
ient location.
REVERSING VALVE REPLACEMENT (38QV Only)
1. Remove coil as described in “Coil Removal,” above.
2. Cut 4 legs of valve using midget tubing cutter.
3. Wrap replacement valve with wet cloth to prevent
overheating.
4. Replace new valve using tubing slip couplings.
MAIN CONTROL BOARD REPLACEMENT
a) Unplug Interface Cable from bottom L.H. side of board
by sfiding small metal retainer right.
b) Unplug white 17 pin connector and two fan motor
push-on leads (Black) from top of board. Use caution to
prevent board damage when removing connections.
c) Using fingers or small tipped pliers, depress plastic
tabs on board standoffs (4) on corners of board and (1)
near center (below black heat sink on board). Lift board
out of position.
d) Align new board on plastic standoffs, and push board
down over standoffs until small locking tabs secure
board in place.
e) Reinstall 2 (black) fan wires and white connector at top
of board. Be sure white connector is aligned correctly.
Reinstall interface cable, sfiding metal locking retainer
to the left.
f) Cut only those program jumpers on new board (ref.
Fig. 5) which were cut on old board.
A CAUTION
Failure to cut the proper programming jumpers wffl
result in improper operation. Jumpers not cut on the
old board must remain uncut. Inadequate operation and
equipment damage may result.
Jumper functions are fisted, in. Table , 3 for reference
purposes.
g) Set Optimizer Pot (ref. Fig. 5) on 38QV Heat Pump
units if jumper, jJ4 or J5 is cut. Adjust to same setting
as old board, or refer to procedure for optimizer or elec­
tric heat lockout setup in 38QV unit Installation
Instructions.
Table 5—Programming Jumpers
Jumper
No.
38QV Heat Pump
Systems
38EV Cooling
Systems
J1 UNCUT CUT
J2,J3 UNCUT UNCUT
J4 CUT FOR 58SSB FURNACE APPLICATIONS
J5 ' CUT FOR ELECTRIC.
HEAT LOCKOUT AT HIGH
OUTDOOR TEMPERATURES*
UNCUT
J6, J7 UNCUT UNCUT
*38QV Systems only
THERMISTOR REPLACEMENT
a) Break power to indoor and outdoor units.
b) For outdoor unit thermistor replacement, remove top
grille.
c) Cut plastic ties holding foam tube over thermistor.
Thermistor is mounted inside %e" copper tube soldered
to refrigerant fines and is retained by one (1) plastic tie.
Remove this tie and remove thermistor.