Fujitsu FO2416RTJNAA Installation Instructions Manual page 44

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