611 / 654
854
HVAC
the moistureby repeated, Recharge new refrigerant
to the specified amount .
•
If casedby dirt; remove theexpansion valveandblow
out the dirt with compressed air. If unable to remove
the dirt, replace the expansion valve. Evacuate and
charge new refrigerant to the specified amount. If
caused by gas leaking from heat sensitizing tube,
replace the expansion valve.
5. EXPANSION VALVE MALFUNCTIONING
(OPENING TOO MUCH) AND IMPROPER
INSTALLATION OF HEAT SENSITIZING TUBE
Condition
•
Air conditioner does not cool effectively
Symptoms in refrigerant cycle
•
Pressure on both the low and high pressure
sides is high
•
Frost or heavy dew is formed on the piping on
the low pressure side
Cause
•
The expansion valve is malfunctioning or the
heat sensitizing tube is improperly installed
•
Flow control is not properly performed
Diagnosis
•
Excessive liquid refrigerant in the low pressure
side piping
•
Expansion valve opened too far
Countermeasures
•
Check the installation of the heat sensitizing
tube
•
If the installation is proper, replace the expansion
valve
6. FAULTYCOMPRESSIONOFCOMPRESSOR
Condition
•
Air conditioner does not cool
Symptoms in refrigerant cycle
•
Pressure on the low pressure sides is too high
and pressure on the high pressure side is too
low
Cause
•
There is leaking in the compressor
Diagnosis
•
Faulty compression of compressor
•
Delivery valve or packing is leaking or broken ,
or compressor is malfunctioning
Countermeasures
•
Check the compressor oil for contamination and
quantity
•
Replace the compressor