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Troubleshooting – Refrigeration Circuit
Symptom
Possible Cause
Refrigerant overcharge.
Liquid floodback.
Tubing rattle.
Compressor noisy
or vibrating
Scroll compressor rotating in reverse (3 phase).
Worn or damaged compressor.
Improper mounting on unit base.
Excessive load on evaporator coil.
Compressor is unloaded.
Expansion valve not secured to suction line.
High suction
pressure
Thermostatic expansion valve pressure limit
feature incorrect or inoperative. Overfeeding.
Room load too large.
Overcharged.
Thermal expansion valve setting.
Too much refrigerant.
Non-condensable in system.
High discharge
pressure
Low water flow rate.
Discharge service valve partially closed.
High load conditions.
Always have a completed Pre Start-Up Checklist, unit Start-Up Checklist, and Optional Accessories Checklist prior to requesting parts or
service information.
Corrective Action
Check pressures and subcooling.
Check thermal expansion valve setting. Check for
refrigerant overcharge.
Dampen tubing vibration by taping or clamping.
Carefully bend tubing away from contact where
possible.
Rewire for opposite rotation.
Replace the compressor.
Check that compressor is properly isolated.
Check for high entering wet bulb temperature.
Check for excessive air.
Check head pressure, check thermal expansion
valve if not functioning properly, check pressure
drop across filter drier.
Check the thermal expansion valve, ensure bulb
is insulated.
Check superheat. If superheat is high, then valve
is out of control and pegged wide open.
• Check bulb for contact.
• Adjust valve for superheat.
• Replace valve powerhead or valve.
Check bulb location and clamping. Adjust
superheat. Replace expansion valve power head.
Reduce the load or add more equipment.
Check pressures and subcooling.
Check thermal expansion setting and calibrate
superheat.
Remove excess refrigerant.
Remove non-condensable from system.
Increase water flow rate.
Open valve.
Add more equipment or reduce load.
Model RT Energy Recovery Unit
45
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