Greenheck Fan 473501 manual Troubleshooting - Unit, Symptom, Possible Cause, Corrective Action

Troubleshooting – Unit

Symptom	Possible Cause	Corrective Action
	CFM too high.	Check cfm and adjust drives if needed.
	Static pressures are higher or lower than design.	If higher, ductwork should be improved.
		If lower, fan rpm should be lower.
Motor over amps	Blower rotation is incorrect.	Check rotation and reverse if necessary.
	Motor voltage incorrect.	Check motor nameplate versus supplied voltage.
	Motor horsepower too low.	See specifications and catalog for fan curves to
		determine if horsepower is sufficient.
	Shorted windings in motor.	Replace motor.
	Unit damper not fully open.	Adjust damper linkage or replace damper motor.
	System static pressure too high.	Improve ductwork to eliminate losses using good
		duct practices.
	Blower speed too low.	Check for correct drives and rpm with catalog data.
	Fan wheels are operating backwards.	For 3-phase, direction can be reversed by
		interchanging any two of the three electrical leads.
Low airflow (cfm)
	Dirty filter.	Follow cleaning procedures in Routine Maintenance
		section.
	Leaks in ductwork.	Repair.
	Elbows or other obstructions may be obstructing	Correct or improve ductwork.
	fan outlet.
	Belt slippage.	Adjust belt tension.
	Blower fan speed too high.	Check for correct fan rpm. Decrease fan speed if
		necessary.
High airflow (cfm)	Filter(s) not in place.	Install filters.
	Insufficient static pressure (Ps) (airflow	Induce Ps into system ductwork. Make sure grilles
		and access doors are installed. Decrease fan speed if
	resistance).
		necessary.
	Fan wheel rubbing on inlet.	Adjust wheel and/or inlet cone. Tighten wheel hub or
		bearing collars on shaft.
	Bearings.	Replace defective bearing(s). Lubricate bearings.
		Tighten collars and fasteners.
	Wheel out of balance.	Replace or rebalance.
	Loose wheel on shaft.	Tighten wheel setscrew.
	Loose motor or blower sheave.	Tighten sheave setscrew.
	Belts too loose.	Adjust belt tension after 24 hours of operation.
Excessive noise
	Belts too tight.	Loosen to maintain a 3/8 inch deflection per foot of
or vibration
		span between sheaves.
	Worn belt.	Replace.
	Motor base or blower loose.	Tighten mounting bolts.
	Buildup of material on wheel.	Clean wheel and housing.
	Bearing and drive misaligned.	Realign.
		Make sure ductwork is supported properly. Make
	Noise being transmitted by duct.	sure ductwork metal thickness is sized for proper
		stiffness. Check duct size at discharge to ensure that
		air velocities are not too high.

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

30 Model ERCH-HP Energy Recovery Unit