Carrier 69NT40-541-306, Операция и обслуживание

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T-354 7–24
7. Unsolder the two coil connections, one at the distributor and the other at the coil header.
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 per Section 7.5 . Evacuate the unit per Section 7.6 , and add refrigerant charge per
Section 7.7 .
7.15.2 Evaporator Heater Replacement
The heaters are wired directly back to the contactor. 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 will detect that a heater set has been disconnected and indicate that the failed heater should be
replaced. To replace a heater, do the following:
1. Before servicing unit, make sure the unit circuit breakers (CB-1 & CB-2) and the start-stop switch (ST) are in
the OFF position, and that 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. Refer to Section 3.3
for heater resistance values. Once the set containing the failed heater is determined, cut the splice connec-
tion 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.
7.16 EVAPORATOR FAN AND MOTOR ASSEMBLY
The evaporator fans circulate air throughout the container by pulling air in through the bottom of the unit. The air is
forced through the evaporator coil where it is either heated or cooled and then discharged out the top of the refrig-
eration unit into the container. The fan motor bearings are factory lubricated and do not require additional grease.
WARNING
!
Always turn OFF the unit circuit breakers (CB-1 & CB-2) and disconnect main power supply
before working on moving parts.
1. Remove upper access panel (See Figure 3.1 ) by re moving mounting bolts and T.I.R. locking device. Reach
inside of unit and remove Ty-Rap securing wire harness loop.
2. Remove the two lower mounting bolts that secure the motor-fan assembly to the unit. Loosen the two upper
bolts as the motor mount upper holes are slotted.
3. Remove motor, fan, and wiring from unit. Place fan motor and fan on a support. Remove the wiring and fan.
4. Lubricate fan motor shaft with a graphite-oil solution (Never-Seez). Apply thread sealer (Loctite H, brown in color)
to the two fan set screws. Install fan on motor. The evaporator fan locating dimension is shown in Figure 7.23 .
Figure 7.23 Evaporator Fan Locating Dimension
8.74 CM
(3.44 INCHES)