Carrier Transicold 69NT40-561-001 Operation And Service Manual Download

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7–15

T-340

7.13.2

Replacing the Filter Drier

1. Pump down the unit (see

Section 7.4

). Evacuate if unit is not equipped with service valves. Then replace fil

ter drier.

2. Evacuate the low side (see

Section 7.6

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

Section 7.4

). Evacuate if unit is not equipped with service valves (see

Section

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

Figure 3.2

) 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.

7.14.2

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

Section 3.3

for

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.