GE Custom 8000 Instructions Manual page 32

DLCGEEP-124-I/000, Approved, 2016-11-11, CampinasDM
Trouble
Low insulation resistance
or insulation failure
(cont'd)
Wound rotor motor:
Motor runs at reduce
speed wit external
resistance out of circuit.
Synchronous generator:
Failure of the machine to
produce rated output.
Brushes sparking
32 GE Industrial Control Systems GEEP-124-I
TROUBLE - SHOOTING CHART
Possible Cause
Mechanical damage to insulation.
Voltage surges have damaged
insulation.
Excessive temperatures
Excessive impedance between
unit and rotor control
Wrong Connections.
Open circuit in rotor (including
cable to control).
Wrong connections
Open circuits
Prime mover
Inadequate excitation
Shorted field turns
Ground in field leads
Overload
Dirt between brush and ring
Brushes stuck in holders
Incorrect brush tension
Rough collector rings
Eccentric rings
Copyright 1997,1998 The General Electric Company, USA
GEEP-124-I Horizontal Induction Motor
WPI, Antifriction Bearing
Obtain expert help for repair.
Obtain expert help for repair
Obtain expert help for repair
Use adequately-sized conductors
Check stator,
connections, check control wiring.
Test by "ringing out" circuit and
repair.
Check stator,
connections, check regulator wiring.
Test by "ring out" circuit and repair.
Check speed, run at rated speed.
Check excitation. Compare with name-
plate and correct.
Impedance check all poles - determine
if one pole is noticeably less than
others.
Check lead
condition where leads exit shaft.
Check for overload with ammeter and
eliminate overload. Clean rings, adjust
brush pressure and replace brushes.
Clean rings, brushes and brush rigging.
Use correct brushes, clean brush
holders.
Check brush tension and correct.
Stone or turn rings.
Turn rings or replace collector.
Action
rotor and exciter
rotor and exciter
insulation - check