MODEL PCA090480WH
CHAPTER 3
TROUBLESHOOTING
Section 4: Troubleshooting Refrigeration System
3-4
March 2013
Page 76
Proprietary/Confidential
© 2013 Twist, Inc.
Trouble IV: Excessive
compressor
vibration
PROBABLE CAUSE
SUGGESTED REMEDY
1. Compressor loose on mounting
1.
Tighten attaching parts as required.
2. Lack of oil
1.
Check oil level and add oil as necessary.
The compressor will likely need to be
replaced.
3. Compressor internally damaged 1. Replace
compressor.
4. Liquid "flood back" caused by
expansion valve being out of
adjustment, loose sensing bulb,
or broken capillary tube.
1.
Retighten sensing bulb, readjust
expansion valve as necessary or replace
power element. (See Chapter 3-6 page
6.)
Trouble V:
Compressor rattles when started
PROBABLE CAUSE
SUGGESTED REMEDY
1.
Compressor electrically out of phase
rotation. The compressor will be noisy
and vibrate excessively. The oil sump
will become warm when running
backwards.
1.
Correct phase rotation to A-B-C.
NOTE:
(Start-up) Under conditions of low refrigerant flows (low suction
pressure) such as at start up, a rattling sound may emanate from
the compressor. This is most likely to be heard under such
conditions of low ambient starts where it takes time to build
sufficient head pressure, allowing the thermal expansion valve to
flow refrigerant and increasing the suction pressure. This sound
should diminish and disappear as the suction pressure increases.
NOTE:
(Flooding) If a compressor should experience severe refrigerant
flooding, it will make a loud "rattling" sound. This is normal because
the separation of the scrolls allows the liquid refrigerant to pass
through the compressor without damage.
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