Carrier Transicold 69NT40-561-001 Operation And Service Manual page 127

7.13.2 Replacing the Filter Drier
1. Pump down the unit (see
ter drier.
2. Evacuate the low side (see
3. After unit is in operation, inspect for moisture in system and check charge.
7.14 Evaporator Coil & Heater Assembly
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.
7.14.1 Evaporator Coil Replacement
1. Pump the unit down (see
7.6.1).
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
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.
7.14.2 Evaporator Heater Replacement
The heaters are wired directly back to the contactor and if a heater failure occurs during a trip, the heater set contain-
ing 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. To remove a heater, do the following:
1. Before servicing unit, make sure the circuit breakers (CB-1 and CB-2) and start-stop switch (ST) are in the
OFF position, and the power plug is disconnected.
2. Remove the upper back panel.
3. Determine which heater(s) need replacing by checking resistance of each heater set. See
heater resistance values. Once the set containing the failed heater is determined, cut the splice connection
and retest to determine the actual failed heater(s).
4. Remove hold-down clamp securing heater(s) to coil.
5. Lift the bent end of the heater (with the opposite end down and away from coil). Move heater to the side
enough to clear the heater end support and remove
To replace a heater, do steps a through e in reverse.
Optional 5+1 Heater Arrangement Heater Removal and Replacement
Complete steps a through e noted above, then remove straight and Omega heaters:
a. To remove straight heater:
1. Locate holding clips positioned at the ends of the heater element.
2. Rotate clips toward the center of the container unit.
3. Lift the heater slightly up and out to remove.
Section 7.4). Evacuate if unit is not equipped with service valves. Then replace fil-
Section 7.6).
Section 7.4). Evacuate if unit is not equipped with service valves (see
Figure
7–15
3.2) from the coil.
Section
Section 3.3 for
T-340