Acer 471558 manual Troubleshooting

Troubleshooting

WARNING: Before taking any corrective action, make certain unit is not capable of operation during repairs.

PROBLEM	CAUSE	CORRECTIVE ACTION
	Wheel rubbing inlet	Adjust wheel and/or inlet cone. Tighten wheel hub or bearing collars
		on shaft.
	V-belt drive	Tighten pulleys on motor/fan shaft. Adjust belt tension. Align pulleys
		properly, see page 6, Figure 9-10. Replace worn belts or pulleys.
	Bearings	Replace defective bearing(s). Lubricate bearings. Tighten collars
		and fasteners.
	Wheel unbalance	Clean all dirt off wheel. Check wheel balance, rebalance in place if
		necessary.
Excessive noise
	Belts too tight or too loose	Adjust tension, see page 7, Figure 12a-b.
or vibration
	Wheel improperly aligned and	Center wheel on inlet, see page 6, Figure 7.
	rubbing
	Loose drive or motor pulleys	Align and tighten. See “Pre-Starting Checks”, see page 6.
	Foreign objects in wheel or housing	Remove objects, check for damage or unbalance.
	Fan base not securely anchored	Secure properly.
	Motor hood loose and rattling	Tighten screws securing motor hood.
	Defective or loose motor bearings	Replace motor with same frame size, RPM-HP.
	Fan	Check rotation of wheel, see page 6, Figure 8. Reduce fan speed.
High horsepower
	Duct system	Resize ductwork. Check proper operation of face and bypass dampers.
		Check filters and access doors.
	Electrical supply	Check fuses/circuit breakers. Check for switches off. Check for correct
		supply voltage.
Fan does
	Drive	Check for broken belts. Tighten loose pulleys.
not operate
	Motor	Assure motor is correct horsepower and not tripping overload protector.
	Lubrication	Check for excessive or insufficient grease in the bearing.
	Mechanical	Replace damaged bearing. Relieve excessive
		belt tension. Align bearings. Check for bent shaft.
	Belt slippage	Adjust tension or replace bad belts, see page 6-7.
Motor overloads	Over/Under line voltage	Contact power company.
or overheats	Incorrect wheel rotation	Check motor wiring (page 4) verify motor is wired for correct rotation.
	Wheel RPM too high	Check drives or slow down fan by opening variable pitch pulley on
		motor shaft.
	Undersized motor	Check motor ratings with catalog speed and air capacity chart.
	Motor wired incorrectly	Check motor wiring to wiring diagram located on fan motor.
	System resistance too high	Check system: Proper operation of backdraft or control dampers,
		obstruction in ductwork, clean dirty filters.
	Unit running backwards	Correct as shown on page 6, Figure 8.
	Excessive dirt buildup on wheels	Clean wheel.
Reduced airflow	Improper wheel alignment	Center wheel on inlets, see Pre-Starting checks on page 6, Figure 7.
	Dampers closed	Inspect and repair.
	Blocked duct/clogged filter	Clean or replace.
	Belt slippage	Replace and adjust tension.
	Speed too slow	Check for correct drives.

®

Model G/GB Centrifugal Roof Exhaust Fans 9