CHIEF Caldwell AF12-751, Owner'S Manual

Page: 33 / 40

Page 33 of 40
Bulletin 441G
E. SYMPTOM: The fan starts and operates for a while and then shuts off.
1. Check the supply voltage. Voltage should be within 10% of rated voltage.
For example, a motor rated at 230 Volt should operate in a voltage range
of 207 to 253 Volts.
2. Check the supply wire sizes required for the fan unit, Page 19 .
3. Check the load on the main circuit to make sure other items on the main
circuit are not overloading the fan circuit.
4.
Check the amperage of the fan, if the unit is pulling above nameplate
amperage; take the motor to an Authorized Service Center.
F. SYMPTOM: Fan operates when main power supply is turned on.
1. The top two terminals of the toggle switch should be checked. If the
circuit is closed between the two terminals, the toggle switch should be
replaced.
2. Check the contact points by removing the front from the contactor to see
if the contacts are locked in or welded in place. If so, the complete
contactor should be replaced.