Greenheck Fan ERH-20, ERH-55, ERH-45 Trouble Shooting, Symptom Possible Cause Corrective Action

Trouble Shooting

Symptom	Possible Cause	Corrective Action
	Blown fuse or open circuit	Replace fuse or reset circuit breaker and check amps.
	breaker.
Blower Fails to	Defective motor or capacitor.	Replace
Operate	Motor starter overloaded.	Reset starter and check amps.
	Electrical.	Check for On/Off switches. Check for correct supply voltage.
	Drive.	Check for broken or loose belts. Tighten loose pulleys.
	Control power (24 Vac) wiring	Shorten wiring run to mechanical room or install a relay
	run is too long (resistance	which will turn unit on/off (C/F for relay information).
	should not exceed 0.75 ohms).
Motor Starters	Incoming supply power is	Need to increase supply power or use a special control
“Chatter” or Do
	less than anticipated. Voltage	transformer which is sized for the actual supply power.
Not Pull In
	supplied to starter coil must
	be within +10% / -15% of
	nominal voltage stated on
	the coil.
	Cfm too high.	Check cfm and adjust drives if needed.
	Static pressures are higher or	If higher, ductwork should be improved.
	lower than design.	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	For 3-phase see Fan Wheel Rotation on page 11.
Low Airflow (cfm)	backwards.
	Dirty filter or energy wheel.	Follow cleaning procedures on pages 14 and 17.
	Leaks in ductwork.	Repair.
	Elbows or other obstructions	Correct or improve ductwork.
	may be obstructing 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)	Induce Ps into system ductwork. Make sure grilles and
	(airflow resistance).	access doors are installed. Decrease fan speed if necessary.

* Always provide the unit model and serial number when requesting parts or service information. * Always check motor amps and compare to nameplate rating.

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