Fujitsu FO2416RTJNAA - Page 44

44
Diagnostics
9.0 DIAGNOSTICS & TROUBLESHOOTING
9.9 Service Analyzer Charts (cont.)
CONTAMINATION
SYMPTOM POSSIBLE CAUSE REMEDY
Moisture Poor evacuation on installation or during service In each case, the cure is the same. Recover refrigerant.
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High head pressure Noncondensibles air Reclaim refrigerant, evacuate, and recharge.
Unusual head and
suction readings
Wrong refrigerant or mixed refrigerants Reclaim refrigerant, evacuate, and recharge.
Foreign matter –
JVWWLYÄSPUNZ
Copper tubing cuttings Reclaim refrigerant, evacuate, and recharge.
Copper oxide Dirty copper piping or nitrogen not used when
brazing
Reclaim refrigerant, evacuate, and recharge.
Welding scale Nitrogen not used during brazing Reclaim refrigerant, evacuate, and recharge.
:VSKLYPUNÅ\_ (KKPUNÅ\_ILMVYLZLH[PUNJVWWLYWHY[^H` Reclaim refrigerant, evacuate, and recharge.
Excess soft solder Wrong solder material Reclaim refrigerant, evacuate, and recharge.
LOSS OF LUBRICATION
SYMPTOM POSSIBLE CAUSE REMEDY
Compressor failures Vapor line tubing too large Reduce pipe size to improve oil return.
Low suction pressure Low charge Check system charge.
Refrigerant leaks Repair and recharge.
Cold, noisy
compressor –
Slugging
Dilution of oil with refrigerant Observe piping guidelines.
Noisy compressor Migration Check crankcase heater.
Cold, sweating
compressor
Flooding Check system charge.
Low load 9LK\JLKHPYÅV^ +PY[`ÄS[LY
Dirty coil
Wrong duct size
Restricted duct
Thermostat setting Advise customer.
Short cycling of
compressor
Cycling or faulty high or low-pressure control Check pressure and address cause of high or low pres-
sure. Replace control if faulty.
Loose wiring Check all control wires.
Thermostat In supply air stream, out of calibration
Customer misuse
SLUGGING
SYMPTOM POSSIBLE CAUSE REMEDY
On start-up Incorrect piping Review pipe size guidelines.
TXV hunting when
running
Faulty TXV Replace TXV.