62-12259 8–34
NOTICE
The scroll compressor achieves low suction pressure very quickly. Do not use the compressor
to evacuate the system below 0 psig. Never operate the compressor with the suction or
discharge service valves closed (frontseated). Internal damage will result from operating the
compressor in a deep vacuum.
22. Following installation of a replacement compressor, the oil level in the unit may be above the required level.
Adjust the oil level in accordance with the instructions packaged with the replacement compressor.
8.8 Refrigerant System Component Service
8.8.1 Evaporator Coil
The use of recycled cardboard cartons is increasing across the country. The recycled cardboard cartons create
much more fiber dust during transport than “new” cartons. The fiber dust and particles are drawn into the evapora-
tor where they lodge between the coil fins. If the coil is not cleaned on a regular basis, sometimes as often as after
each trip, the accumulation can be great enough to restrict air flow, cause coil icing, repetitive defrosts and loss of
unit capacity.
Due to the “washing” action of normal defrost the fiber dust and particles may not be visible on the face of the coil
but may accumulate deep within.
Clean the evaporator coil on a regular basis, not only to remove cardboard dust, but to remove any grease or oil
film which sometimes coats the fins and prevents water from draining into the drain pan.
Cardboard fiber particles after being wetted and dried several times can be very hard to remove. Therefore, sev-
eral washings may be necessary.
1.
Ensure the unit will not start automatically by placing the START/RUN-OFF switch in the OFF position and
removing the negative battery cable.
Disconnect the high voltage source and lockout/tagout the receptacle.
2. Remove rubber check valves (Kazoo) from drain lines of the evaporator to be cleaned.
3. Spray coil with a mild detergent solution, such as Oakite 164 or 202, or any good commercial grade
automatic dish washer detergent and let the solution stand for a few minutes and reverse flush (opposite
normal air flow) with clean water at mild pressure. A garden hose with spray nozzle is usually sufficient.
Make sure drain lines are clean.
4. Re-install check valves and run unit until Defrost mode can be initiated to check for proper draining from
drain pan.
8.8.2 Condenser Coil
8.8.2.1 Cleaning
NOTE
Only clean water should be used to wash the condenser coil. Do not use any detergents to clean the
condenser.
Remove all foreign material from the condenser coil by reversing the normal air flow. (Air is pulled in
through the front and discharges over the engine.) Compressed air or water may be used as a cleaning
agent. Take care so that the fins aren’t bent during this procedure.
8.8.2.2 Condenser Coil Replacement
1. Remove the refrigerant charge. Refer to Section 8.6.2.
NOTE
If the condenser coil (Figure 8.21) requires replacement, the entire condenser/radiator assembly must
be removed from the unit and disassembled/reassembled on the bench.
2. Drain coolant into a suitable container by removing coolant bottle cap and then the engine drain plug.
3. Remove the surround with the grille attached. Refer to Section 8.4.3.
4. Remove hoses from radiator.
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