Maintenance; General; Compressor Failure; Electrical Failure-Burnout - Emerson Liebert Prop Fan Condensing Unit Installation, Operation And Maintenance Manual

4.0 M
AINTENANCE
4.1

General

Access the condensing unit by removing the unit housing panel. Clean the air cooled condenser coil of
all debris that will inhibit airflow. This can be done with compressed air or with a commercial coil
cleaner. Check for bent or damaged coil fins and repair as necessary. During winter, do not permit
snow to accumulate on or around the condensing unit. Check all refrigerant lines and capillaries for
vibration isolation and support as necessary. Check all refrigerant lines for signs of leaks.
WARNING
!
Turn Off power to unit at disconnect switch unless you are performing tests that require
power. With power and controls energized, unit could begin operating automatically at any
time.
WARNING
!
Hazardous voltage will still be present at condenser even with power turned Off at the control
panel. To isolate unit for maintenance, turn the unit Off at disconnect switch.
CAUTION
!
If condenser power is disconnected for a long period, do not attempt to start the condensing
unit until 8 hours after restoring power. This allows time for liquid refrigerant to be driven
out of the compressor. This is especially important at low ambient temperatures.
4.2

Compressor Failure

If a compressor motor burns out, the stator wiring insulation decomposes, forming carbon, water and
acid. Not only must the compressor be replaced, but the entire refrigeration circuit must be cleaned of
the harmful contaminants left by the burnout. Successive burnouts of the same system can usually be
attributed to improper system cleaning.
WARNING
!
Damage to a replacement compressor caused by improper system cleaning constitutes abuse
under the terms of the warranty.
Before proceeding with a suspected burnout, check all electrical components: fuses, contactors and
wiring. Check high-pressure switch operation. If a compressor failure has occurred, determine
whether it is an electrical or mechanical failure. An electrical failure will be indicated by a distinct,
pungent odor. If a severe burnout has occurred, the oil will be black and acidic. In the case of a
mechanical failure, there will be no burn odor and the motor will attempt to run.
4.2.1 Electrical Failure—Burnout
In the event that there is an electrical failure and a complete burnout of the refrigeration compressor
motor, the proper procedures must be performed in order to clean the system to remove any acids that
would cause a future failure.
NOTE
Failure to properly clean the system after a compressor motor burnout will void the compressor
warranty. Follow the manufacturer's procedure.
CAUTION
!
Avoid touching or contacting the gas and oils with exposed skin. Severe burns may result. Use
long rubber gloves in handling contaminated parts.
4.2.2

Mechanical Failure

If a mechanical failure has occurred, the compressor must be replaced.
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Maintenance