Greenheck Fan 473501 manual Troubleshooting - Refrigeration Circuit, Symptom, Possible Cause

Troubleshooting – Refrigeration Circuit

Symptom	Possible Cause	Corrective Action
	Refrigerant overcharge.	Check pressures and subcooling.
	Liquid floodback.	Check thermal expansion valve setting. Check for
		refrigerant overcharge.
		Dampen tubing vibration by taping or clamping.
Compressor noisy	Tubing rattle.	Carefully bend tubing away from contact where
or vibrating		possible.
	Scroll compressor rotating in reverse (3 phase).	Rewire for opposite rotation.
	Worn or damaged compressor.	Replace the compressor.
	Improper mounting on unit base.	Check that compressor is properly isolated.
	Excessive load on evaporator coil.	Check for high entering wet bulb temperature.
		Check for excessive air.
		Check head pressure, check thermal expansion
	Compressor is unloaded.	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
High suction	Expansion valve not secured to suction line.	out of control and pegged wide open.
pressure		• Check bulb for contact.
		• Adjust valve for superheat.
		• Replace valve powerhead or valve.
	Thermostatic expansion valve pressure limit	Check bulb location and clamping. Adjust
	feature incorrect or inoperative. Overfeeding.	superheat. Replace expansion valve power head.
	Room load too large.	Reduce the load or add more equipment.
	Overcharged.	Check pressures and subcooling.
	Thermal expansion valve setting.	Check thermal expansion setting and calibrate
		superheat.
	Air inlet to condenser dirty or obstructed.	Check for proper clearances and possible air
		recirculating.
	Condenser fan motor defective.	Check condenser fan motor.
	Too much refrigerant.	Remove excess refrigerant.
High discharge
	Non-condensable in system.	Remove non-condensable from system.
pressure
	Dirty condenser coil.	Clean condenser coil.
	Condenser fan not running or running	Check electrical circuit and fuse. Check fan cycling
	backwards.	controls.
	Discharge service valve partially closed.	Open valve.
	High load conditions.	Add more equipment or reduce load.

Always have a completed Pre Start-Up Checklist and Unit Start-Up Checklist prior to requesting parts or service information.

Model ERCH-HP Energy Recovery Unit 33