Troubleshooting guide

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Multiquip Inc. ◦ DCA Generators Troubleshooting Guide ◦ Manual No. DCATRBLSHOOT
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This manual is intended to suggest a systematic approach to locating and correcting generator
malfunctions. The steps have been arranged in an attempt to do the easy checks first and prevent further
damage when troubleshooting a disabled machine.
The first step of troubleshooting is to gather as much information as is possible from operating personnel
and individuals present during the failure. Typical information includes:
 How long the unit had been operating;
 What voltage was the generator running at when the fault occurred;
 What loads were on line;
 Information about the application the generator was operating is sometimes crucial to determine
fault and cause of fault;
 Prior issues with machine;
 Maintenance history;
 Weather conditions;
 Protective equipment that did or did not function;
In addition, information as to the operating condition of the generator's prime mover is vital.
 Has the prime mover been maintaining constant speed? If not, have there been extended periods of
under speed operation?
 Has the prime mover experienced an over-speed condition? If yes, what was the maximum speed,
and how long did the unit operate at that elevated speed?
The generator speed should be maintained at rated nameplate value during all operating tests. The
frequency of the generator depends upon rotational speed.
Always make a thorough visual inspection to check for obvious problems before attempting to run the
generator. Remove covers and look for any obvious problems. Burnt windings, broken connectors, burnt
wires, mounting brackets, etc., can usually be identified through inspection. Look for any loose or frayed
insulation, loose or dirty connections and broken wires. Check for any foreign objects, loose nuts, bolts and
electrical connections.
If possible rotate the generator rotor by hand to be sure it turns freely.
If serious problems can be identified before attempting to operate the machine, additional damage can be
avoided.