Norton Abrasives C6136 - Manual (Page 48)

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3. Place a few drops of oil on felt liner in head assembly.
4. Check brush set for wear and replace if necessary.
5. Blow dirt and dust out of motor housing and check for
shorts, burnt wires, or open circuits in the field coil
assembly.
6. Check armature and commentator for shorts or open
circuits.
7. Check ball bearings on motor shaft, a growling motor can
be caused by bad bearings.
8. Check for excessive "end play" of armature and add thrust
washers as required.
9. If there is an excessive amount of water, condensation, or
rust in the motor, a small drain hole may be drilled in the
motor case on the low side of the motor depending on the
mounting; consult with factory for additional information.
NOTE: A motor that does not turn in freezing weather could
be caused by water that has frozen inside the housing.
10. All Monarch DC motors turn counterclockwise when
viewed from drive end; it checks it when replacing motor
with new one.
11. If motor fails to turn the pump, check the pump by turning
drive shaft by hand.
F. Electrical Switches
Defective switches are a common cause of electrical
malfunction. What seems to be a serious system defect can
often be caused simply by a faulty switch, especially where
the switch controls two functions, that is, start the motor and
shift a valve. In most cases one half of the switch might be
defective while the other half operates correctly and the fault
appears to be with some other component. Trouble shooting
can be done by any one of the three methods:
1. Use”continuity light" to test switch. (See Test Equipment
Section)