Carrier PrimeLINE 69NT40-561-200, Operation And Service Manual

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7–21 T-362
2. Evacuate the low side in accordance with Section 7.6 .
3. After unit is in operation, inspect for moisture in the system and check charge.
7.15 Evaporator Coil
The evaporator section, including the evaporator coil, should be cleaned regularly. The preferred cleaning fluid is
fresh water or steam. Another recommended cleaner is Oakite 202 or similar, following manufacturer’s instructions.
The two drain pan hoses are routed behind the condenser fan motor and compressor. The drain pan line(s) must
be open to ensure adequate drainage.
7.15.1 Evaporator Coil Replacement
1. Pump unit down. See
Section 7.4
.
WARNING
!
Always turn OFF the unit circuit breakers (CB-1 & CB-2) and disconnect main power supply
before working on moving parts.
2. With power OFF and power plug removed, remove the screws securing the panel covering the evaporator
section (upper panel).
3. Disconnect the defrost heater wiring.
4. Remove the mounting hardware from the coil.
5. Unsolder the two coil connections, one at the distributor and the other at the coil header.
6. Disconnect the defrost temperature sensor (see
Section 7.29 ) from the coil.
7. Remove middle coil support.
8. After defective coil is removed from unit, remove defrost heaters and install on replacement coil.
9. Install coil assembly by reversing above steps.
10. Leak check connections. Evacuate and add refrigerant charge.
7.16 Evaporator Heaters
Figure 7.10 Heater Arrangement
1) Heater Element
2) Bracket
3) Retainer
- - - - -
The heaters are wired directly back to the contactor and if a heater failure occurs during a trip, the heater set containing
that heater may be disconnected at the contactor.
The next pre-trip (P1) will detect that a heater set has been disconnected and indicate that the failed heater should be
replaced.
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