BOOK 0958-B
TABLE 6. TROUBLESHOOTING
INDICATION | POSSIBLE CAUSE |
9. Line and motor arma | Motor overloaded | |
ture current excessive | ||
|
| Open shunt field winding or wiring to | |
| the motor shunt field | |
10. Shunt field current a |
| |
Shunt field connected for incorrect | ||
too low | ||
voltage | ||
| ||
|
| |
| Diode D39, D40, D41, or D42 failure | |
|
| |
| Shunt field connected for incorrect | |
11. Shunt field current a | voltage | |
| ||
| ||
too high | Shunt field windings shorted | |
| ||
|
| |
| Ventilation insufficient | |
|
| |
| Excessive motor load at low speed | |
|
| |
12. Motor thermal guard | Line and motor armature current | |
tripped (if used) | excessive | |
|
| |
| Motor overheating from friction | |
|
| |
| Shorted motor windings or faulty bear- | |
| ings |
CORRECTIVE ACTION
Check shunt field current.a Low shunt field current causes excessive armature current. If field current is adequate, check for a mechani cal overload. If the unloaded motor shaft does not rotate freely, check motor bearings. Also check for a shorted motor armature. Motor overload can also be caused by incorrect gear ratio. Correct accordingly.
Check the motor shunt field and associated circuitry for a loose connection or a broken wire. Repair accordingly.
Check motor rating and refer to Table 12 on page 34.
Replace faulty diode or the control board.
Check motor rating and refer to Table 12 on page 34.
Measure the shunt field resistance and com pare with the motor rating. Repair or replace the motor.
Remove dirt, dust, and debris from the motor intake and exhaust screens.
Reduce the load or increase the speed.
See Indication 9.
Check for misalignment. Realign the motor.
Repair or replace the motor.
a. Does not apply to
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