FAILURE OF MOTOR BY FLASHOVER IN STATOR
FAILURE OF MOTOR BY FLASHOVER IN STATOR
(OP)
IT IS OBSERVED THAT MOTOR HAS FAILED BY FLASH OVER IN THE STATOR. THE MOTOR WAS PROVIDED WITH TEMPERATURE SCANNER TO MONITOR & CONTROL THE WINDING TEMPERATURE. THIS PROTECTION COULD NOT WORKED. ANOTHER PROTECTION IS THROUGH MOTOR PROTECTION RELAY. HOWEVER THIS RELAY DO NOT COVER PHASE IMBALANCE & EARTH LEAKAGE PROTECTION. THE MOTOR IS ENERGY EFFICIENT TYPE. THE HELP IS EXPECTED TO FIND OUT THE CAUSE & TO AVOID THE RECURRENCE OF THE FAILURE.





RE: FAILURE OF MOTOR BY FLASHOVER IN STATOR
possible causes may be
1.Accumalation of conducting dust in the motor terminal boxes
2.loose termination in the terminals
3.sudden increase of mechanical load /Jamming of motor shaft
4.problem with supply voltage fluctuations
the exact reason has to analyzed if you provide more details as requested above
regards
eswaran
of th
RE: FAILURE OF MOTOR BY FLASHOVER IN STATOR
So I'm not sure how the comments about motor protection relate:
Did you see evidence of thermal degradation of the winding?
Have you recorded abnormal winding temperatures?
Did any protective relay actuate? Which one? Do you suspect improper relay operatoin? Why?
On what basis do you identify this as a flashover? Did you observe the failed stator? Could you identify the point of failure on surface? If so please describe where on the coil it was?
RE: FAILURE OF MOTOR BY FLASHOVER IN STATOR
In 1966 a consultant wrote: Contamination is probably the most common cause of motor failure, and claimed the single most common reason for bearing failure was contamination of bearing entrance of foreign material.
In 1974 IEEE completed an Industrial Plant survey and found that one-third of the motor failures were traceable to chemical, moisture, dust, and solvent attack, plus blockage of ventilation by such materials.
It is well known that 90% of motor failures today are due to four causes:
1. dirt
2. moisture
3. friction
4. vibration
The most common contaminants are:
* conductors, such as carbon duct
* hydrophyllic compounds, materials that absorb moisture from the air, such as salt.
* solvents
* corrosive chemicals, mostly acids and alkalis
and lets not foget about air borne dangers such as metal dust. This attacks in several ways, it is conducting and contribuites to winding breakdown by surface tracking. Second, it is abrasive, once deposited on windings, particles continually vibrate under the influence of the motor, eventually cutting their way through insulation.
RE: FAILURE OF MOTOR BY FLASHOVER IN STATOR
of th
pl inform yr e mail id enable to send the photographs by mail of the damaged stator
regards
My email ID badveud@pnq.kpcl.co.in
RE: FAILURE OF MOTOR BY FLASHOVER IN STATOR
RE: FAILURE OF MOTOR BY FLASHOVER IN STATOR