Carrier 69NT40-561-019, Руководство по эксплуатации и обслуживанию

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T-359 7–12
7.8 FILTER DRIER
If the liquid line sight glass appears to be flashing or bubbles are constantly moving through the sight glass, the
unit may have a low refrigerant charge or the filter drier could be partially plugged.
a. To check filter drier:
1. Test for a restricted or plugged filter drier by feeling the liquid line inlet and outlet connections of the drier
cartridge. If the outlet side feels cooler than the inlet side, then the filter drier should be changed.
2. Check the moisture-liquid indicator if the indicator shows a high level of moisture, the filter drier should
be replaced.
b. To replace filter drier:
1. Pump down the unit (refer to Section 7.3.2 ). Evacuate if unit is not equipped with service valves.
Then replace filter drier.
2. Evacuate the low side in accordance with Section 7.3.4 .
3. After unit is in operation, inspect for moisture in system and check charge.
7.9 EVAPORATOR COIL AND HEATER ASSEMBLY
The evaporator section, including the coil, should be cleaned regularly. The preferred cleaning fluid is fresh water
or steam. Refer to
Section 7.11 for additional Evaporator Coil cleaning instructions.
The drain pan hose is routed behind the condenser fan motor and compressor. The drain pan line must be open to
ensure adequate drainage.
7.9.1 Evaporator Coil Replacement
a. Pump unit down. (Refer to Section 7.3.2 ) Evacuate if unit is not equipped with service valves.
Refer to Section 7.3.4 .
b. With power OFF and power plug removed, remove the screws securing the panel covering the
evaporator section (upper panel).
c. Disconnect the defrost heater wiring.
d. Remove the mounting hardware from the coil.
e. Unsolder the two coil connections, one at the distributor and the other at the coil header.
f. Disconnect the defrost temperature sensor (see Figure 3.2 ) from the coil.
g. Remove middle coil support.
h. After defective coil is removed from unit, remove defrost heaters and install on replacement coil.
i. Install coil assembly by reversing above steps.
j. Leak check connections. Evacuate and add refrigerant charge.
7.9.2 Evaporator 5+1 Heater Removal and Replacement
The heaters are wired to the contactor and to the terminal block. If a heater failure occurs during a trip, the heater
set containing that heater may be disconnected at the contactor or at the terminal block. Refer to the schematic
diagram to individually isolate and troubleshoot the heaters.
The next pre-trip 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:
a. Before servicing unit, make sure the unit circuit breakers (CB-1 and CB-2) and the start-stop switch (ST)
are in the OFF position, and that the power plug is disconnected.
b. Remove the upper back panel.