Page text (OCR transcript)
AIR CONDITIONING SYSTEM — Troubleshooting AC-7
7. AIR PRESENT IN REFRIGERATION SYSTEM
Condition: Does not cool down sufficiently
NOTE: These gauge indications are shown when the
refrigeration system has been charged with refrigerant
charged without vacuum purging.
Symptom seen in
refrigeration system Probable cause Diagnosis Remedy
Pressure too high at both Air entered in refrigeration Air present in refrigeration (1) Replace receiver and
low and high pressure sides system system drier
(2) Check compressor oil
Insufficient vacuum to see if dirty or in-
purging sufficient
(3) Vacuum purge and
charge new refrigerant
8. REFRIGERANT DOES NOT CIRCULATE
Condition: Does not cool (Cools from time to time in
some cases)
Symptom seen in
refrigeration system Probable cause Diagnosis Remedy
Vacuum indicated at high Refrigerant flow obstructed Expansion valve orifice Allow to stand for some time
pressure side, very low by moisture or dirt in clogged and then restart operation
pressure indicated at high receiver or foreign matter to determine if trouble is
pressure side adhering to expansion valve Refrigerant does not flow caused by moisture or dirt
If caused by moisture refer
Frost or dew seen on piping Refrigerant flow obstructed to step 2 on page AC-4
before and after receiver by gas leakage from expan- If caused by dirt, remove
and drier or expansion valve sion valve heat sensing tube expansion valve and clean off
dirt by blowing with air. If
unable to remove dirt, replace
valve.
Vacuum purge and charge
new refrigerant to proper
amount
If gas leakage from heat
sensing tube, replace expan-
sion valve