HP - G 2
Refrigeration Cycle Problems
Check Procedures
Filter Drier Check
The filter drier functions to remove debris and
contaminants from the refrigerant. The debris or
contaminants can sometimes plug the filter drier and
restrict the flow of refrigerant, causing system
performance to degrade.
Step 1
To check for a plugged filter drier, perform a
temperature check at the inlet and outlet of the filter
drier (Figure 1).
Step 2
The temperature difference should be no greater than
3°F. A temperature differential greater than 3°F
indicates a restriction. Replace the filter drier.
Figure 1
Tools You Will Need:
* Temperature Probe
Tools You Will Need:
Reversing Valve Check
The reversing valve uses a 24 volt coil to magnetically
shift a spool inside the valve to direct the flow of refrig-
erant. This coil is energized during cooling mode and
the defrost cycle of the heat pump mode. Failure of
the coil or electrical circuit allows the valve to default
to the heat pump mode (without defrost cycle).
* Multimeter
* Screwdriver
Figure 2
COOLING MODE
Step 1
When a call for cooling is received, yet the unit oper-
ates as if in the heat pump mode, check for 24 volts at
the reversing valve coil (Figure 2).
Note: Troubleshooting liquid line filter driers and check
valves (when not in the checked position) is similar.
Both components should allow a free flow of refrigerant
without restriction. A 3degree F temperature drop
across a check valve indicates a restricted screen
internal in the check valve. The check valve and liquid
line filter drier should be replaced.
To Next Page
Loading...
