CHIEF Caldwell AF12-751, Руководство пользователя

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Bulletin 441G
4. Check holding coil. (If coil is defective, replace)
a. Make sure there is power from L2 on the contactor to the holding
coil.
b.
Make sure there is power going from L1 through the motor
thermostat wires and the toggle switch. If power is available at
the coil, the coil is defective.
5. Check to be sure that the contact set is not restricted from closing.
B. SYMPTOM: The fan just hums when turned on.
1. Check to make sure that all leads of your power source have voltage
present. If fan unit is not receiving power on all leads, check for a blown
fuse, broken wire, or loose connection.
2. Check to see that all contact sets are closing. If one leg of the supply
voltage is not available to the motor, the motor will hum.
a. Remove the front cover from the contactor, turn the fan unit on
and watch to see that all contacts close. If all contacts do not
close, clean or replace contactor.
3. If power is available at all the motor leads and the motor still hums, then
the motor should be taken to an authorized Service Center for repair or
replacement.
a. The power can be hooked directly to the motor leads (for
testing), if the motor hums, replace or repair the motor.
C. SYMPTOM: Fan operates when the toggle switch is held in the
“START” position but shuts off when the toggle switch is in the “RUN”
position.
1. Check toggle switch as referenced in Symptom A, Number 2.
2. Check the auxiliary switch; locate on the side of the contactor. (If
defective, replace auxiliary switch. Refer to
Figure 25 on Page 36 to
determine the part required for your fan model.)
a. With the power supply OFF remove the front plate from the
contactor the auxiliary switch should be open. Switch should
close when the contact sets are pushed in. Circuit is checked by
measuring the resistance across the auxiliary switch.
D. SYMPTOM: The Fan only comes up to ½ speed.
1. Take the motor to an Authorized Service Center for repair or replacement.