Carrier 69NT40-561-019, Operation And Service Manual

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7–15 T-359
Figure 7.8 Evaporator Fan Assembly
1. Stator
2. Flat washer, 5/8
3. Locknut, 5/8-18
4. Impeller Fan
5. Screw, 1/4
6. Flat washer, 1/4
7. Mylar Protector
8. Evaporator Motor
- - - - -
e. Install the evaporator fan assembly in reverse order of removal. Torque the four 1/4-20 clamp bolts to
0.81 mkg (70 inch-pounds). Connect the wiring connector.
f. Replace access panel making sure that panel does not leak. Make sure that the TIR locking device is
lockwired.
7.11 EVAPORATOR SECTION CLEANING
Containers and Container units that are exposed to certain fumigants may develop visible surface corrosion. This
corrosion will show up as a white powder found on the inside of the container and on the reefer unit evaporator sta-
tor and fan deck.
Analyses by Carrier Transicold environmental specialists have identified the white powder as consisting predomi-
nantly of aluminum oxide. Aluminum oxide is a coarse crystalline deposit most likely the result of surface corrosion
on the aluminum parts within the container. If left untreated over time, it may build up in thickness and eventually
flake as a light-weight white powder.
The surface corrosion of aluminum is brought about by exposure to chemicals such as sulfur dioxide and possibly
other fumigants that are commonly used for fumigation and protection of some perishable cargo such as grapes,
for example. Fumigation is the process by which a chemical is released into an enclosed area to eliminate infesta-
tions of insects, termites, rodents, weeds and soil-born disease.
Typically any aluminum oxide that becomes detached from evaporator fan stators will be blown into the wet evapo-
rator coil where it will be caught and then flushed out of the unit during routine defrost cycles.
However, it is still highly recommended that after carrying cargo subject to fumigation procedures, that the inside of
the unit be thoroughly cleansed prior to reuse.
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