Carrier 69NT40-561-300, Operation And Service Manual

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T-365 7–8
7.8 COMPRESSOR
WARNING
!
Make sure power to the unit is OFF and power plug disconnected before replacing the com-
pressor.
WARNING
!
Before disassembly of the compressor, be sure to relieve the internal pressure very carefully
by slightly loosening the couplings to break the seal.
CAUTION
!
The scroll compressor achieves low suction pressure very quickly. Do not use the compressor
to evacuate the system below 0 psig. Never operate the compressor with the suction or dis-
charge service valves closed (frontseated). Internal damage will result from operating the com-
pressor in a deep vacuum.
7.8.1 Removal and Replacement of Compressor
1. Turn the unit start-stop switch (ST) and unit circuit breaker (CB-1) OFF, and disconnect power to the unit.
Follow the regional lock out tag out procedure for electrical system.
2. Remove the compressor guard and install R134a manifold gauges on the compressor suction and discharge
service valves.
3. Remove the Digital Un-loader (DUV) coil and place the magnet on the valve stem to open the coil. Leave
magnet on the coil. If a magnet is not available perform the Jumper procedure:
a. Remove all 4 controller fuses (F1, F2, F3a, F3b).
b. Remove the KA6 wire from KA controller connector on the front of the controller.
c. Disconnect the X1 wire from the 24VAC side of transformer (black wire) and locate it away for the trans-
former.
d. Jumper between the black transformer wire to the KA6 wire removed from the connector.
e. Connect power to unit and turn circuit breaker on (DUV coil is now energized).
4. Connect a refrigerant recovery machine and and recover any refrigerant out of the compressors and DUV
line following the recovery machine recommendations (refer to the recovery machines Operation and Ser-
vice manual for proper procedures).
5. If a jumper was used in step c, on completion of the recovery turn the circuit breaker off and disconnect the
power. Follow the regional lock out tag out procedure for electrical system.
6. Remove the compressor terminal cover, disconnect the ground wire and remove (pull) the cable plug from
the compressor terminals. Install the terminal cover back after removing the power cable.
NOTICE
Inspect the power cable (plug) terminals to ensure they are not deformed or have any signs of
heat or arcing. If any damage is noted replace the power cable.
7. Remove the rotalock fittings from the suction and discharge service connections, and uncouple the unloader
and economizer lines from the compressor.
8. Cut the dome temperature sensor wires. The replacement compressor comes with a dome temperature sen-
sor already assembled.
9. Remove and save the compressor base-mounting screws. Discard the resilient mounts and washers.