MODEL PCA090480WH
CHAPTER 3
TROUBLESHOOTING
Section 4: Troubleshooting Refrigeration System
March 2013
3-4
Proprietary/Confidential
Page
75
© 2013 Twist, Inc.
Trouble III: Insufficient
cooling
PROBABLE CAUSE
SUGGESTED REMEDY
1.
Shortage of refrigerant
1.
Verify refrigerant charge. Add refrigerant
as necessary. (See Chapter 3-6 page 1.)
2. Clogged filter-drier
1.
Check by touch if in-and-out temperature
difference can be sensed. Replace as
necessary. (See Chapter 3-6 page 2.)
3. Expansion valve clogged or
mechanically malfunctioning
1.
Repair or replace assembly. (See
Chapter 3-6 page 4.)
4.
Obstructed air to the condenser
coils
1. Clean
coils.
5. Air or other non-condensable
gases in the system
1.
Check and purge system and/or replace
refrigerant charge as necessary. (See
Chapter 3-6 page 1.)
6. Excessive refrigerant charge
1.
Reclaim excess refrigerant from system.
(See Chapter 3-6 page 9.)
7. Evaporator coil frosted or frozen,
causing low suction pressure
1.
Evaporator coil(s) freeze up. (See
Chapter 3-5 page 6.)
8.
Improper superheat adjustment
1.
Check superheat and reset thermostatic
expansion valve. (See Chapter 2-8 page
1.)
9. Evaporator
Pressure
Regulator
out of adjustment
1.
Adjusted as directed in Chapter 3-6 page
3.
10. Compressor malfunctioning
1.
Replace compressor.
11. Overcharge of refrigerant or non-
condensable gas in system,
causing high discharge
pressures
1.
Reclaim refrigerant, remove non-
condensable gas from refrigerant, and re-
install refrigeration in system. Verify
system operations.
12. Controller not operating properly 1.
Check temperature settings on device
and correct or replace component as
necessary.
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