MODEL PCA090480WH
CHAPTER 3
TROUBLESHOOTING
Section 5: Helpful Troubleshooting information
3-5
March 2013
Page 86
Proprietary/Confidential
© 2013 Twist, Inc.
4. Clogged
Filter-Drier
Occasionally the filter-drier in the liquid line may become clogged with dirt or
other foreign material left in the system during assembly or servicing. When
this happens, the liquid leaving the filter-drier will feel cooler than the liquid
entering. If it is badly clogged, some sweat or frost may appear at the filter-
drier outlet.
If the drier is frosted or if there is a perceptible temperature change between
the liquid line entering and leaving the drier, an excessive pressure drop in the
drier is indicated, and the drier should be replaced
.
5.
Dirty Condenser Coil
When condensers become filled with dust or dirt between the fins, remove the
louvers for access. First, remove excess dirt from condensers with soft-
bristled paintbrush. Second, use air or water to remove any loosened residue.
Apply water or airflow so that residue is directed away from the coil instead of
into the coil. In a severe environment, use a non-acid, alkaline based, coil
cleaning solution as described below.
U
WARNING
U
: THEN USING AIR (NOT MORE THAN 30 PSIG) FOR
CLEANING, IT IS VERY IMPORTANT TO FOLLOW NORMAL
SAFETY PROCEDURES, OR SERIOUS PERSONAL INJURY
CAN RESULT.
6.
Hot gas By-pass Valve Obstructed
The hot gas by-pass valve in the downstream refrigeration systems maintains
a minimum evaporator coil temperature by controlling the suction pressure to
the evaporator coil. If the valve is clogged or inoperative, no control is
maintained. Check if the solenoid valve upstream of the valve is opened. The
solenoid valve is controlled by the ALC output.
7.
Hot Gas By-pass Valve Adjustment Procedure
This procedure is more easily performed when ambient air temperature is
below 85 degrees F.
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