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9. SERVICE
9.1 INITIAL INSPECTION
After the system has been charged and has operated for at
least two hours at normal operating conditions without any
indication of malfunction, it should be allowed to operate
overnight on automatic controls. Then a thorough inspection
of the unit operation should be made as follows:
1. Check for any vibration in the unit.
2. Check liquid line sight glass and proper operation of
expansion valve. If additional refrigerant seems to be
required, leak test all connections. Repair any leaks
before adding refrigerant.
3. Thermostatic expansion valves must be checked for
proper superheat settings. Sensing bulbs must be
in positive contact with the suction line and should
be insulated. Valves set at high superheat will lower
refrigeration capacity. Low superheat may cause liquid
slugging and compressor bearing washout.
4. Check defrost controls for initiation and termination
settings and length of defrost period. Set fail safe at
length of defrost + 25%. Example: 20 minute defrost + 5
minutes = 25 minute fail safe
5. Check drain pan for proper drainage.
9.2 PERIODIC INSPECTIONS
All units should be checked at least once a month for proper
defrosting. It may be necessary to periodically change the
number of defrost cycles or adjust the duration of defrost.
Under normal usage conditions, proper unit maintenance
should be done every six months to include the following:
1. Check all wiring and insulators.
2. Check and tighten all electrical connections.
3. Inspect contactors for proper operation and for worn
contact points.
4. Check all fan motors. Tighten motor mount bolts/nuts
and tighten fan set screws.
5. Clean condenser coil surface.
6. Check refrigerant and oil level in the system.
7. Check operation of the control system ensuring all safety
controls are operating properly.
8. Check all defrost controls are functioning properly.
9. Clean the unit coil surface.
10. Clean the drain pan and check the drain pan drain line
for proper drainage.
11. Check drain line heater for proper operation, cuts and
abrasions.
12. Check and tighten all are connections.
See troubleshooting chart for troubleshooting information.
CAUTION: Before starting unit, be sure wire fan
guards are securely fastened over each fan.
9.3 CLEANING
WARNING! Before carrying out any cleaning or
maintenance of the unit, always check to make
sure main power to systems is OFF.
Electrical shock can cause personal injury or
death.
The unit should be checked periodically for dirt accumulation.
Grease and dust should be removed from the fan, fan
guards, and drain pan.
Occasional cleaning of nned surfaces can be done by
dusting the ns and then cleaning with a mild detergent and
warm water spray.
Always pressure clean in reverse of the air ow.
IMPORTANT: Do not use alkaline or acidic solutions; they
will damage the coils. Remove the fan guards to clean the
inner face of the coil.
SERVICE
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