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Vibrations in buildings/Structures - Effects in Electrical systems.

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charz

Electrical
Jan 11, 2011
95
I have earlier posted about the failure of capacitors in a pumping installation vide thread Link. Recently we have a observed a pattern of loosening of bolts/nuts in several starter panels where the capacitors are mounted. Under these structures discharge lines passes through for a short line before draining the water into canal. We feel that loosening of bolts/nuts is due to the vibration of building/structures due to pumping. Does this mechanical vibration (building/structures) have any relation to the capacitor failures?
 
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Certainly seems like a possibility that excess vibration could wear though the very thin insulation used in capacitors.
 
Have begun experiencing pressure switch failures in a 230 kV switchyard employing air blast breakers; when end-of-life pressure switches were replaced, someone forgot when specifying new switches to ensure they were suitable for use in breaker mechanism boxes. New pressure switches were thought to have been "failing prematurely" until a maintainer read the manual supplied with the replacement switches and learned that these were not for use in vibratory applications. Needless to say, air blast breakers do vibrate just a little when operating...and even the magnitude of the vibrations occurring when the breaker fill solenoids were opening and closing were found to be of sufficient magnitude to damage the replacement pressure switches. Scrambling to address the problem is ongoing...

Not sure if this is what OP was inquiring about, but there it is, for whatever it's worth.

CR

"As iron sharpens iron, so one person sharpens another." [Proverbs 27:17, NIV]
 
As a start, Can you feel vibration on the starter panels when the pumps are operating? Middle and edges.

If yes, then more sophisticated measurements are need to determine if the vibration is excessive, the frequencies of the vibrations, and if perhaps the vibration is excessive because it is being amplified due to resonance.
 
Self-loosening fasteners and self-immolating capacitors in the same enclosure make me want to ask if there could be a thermal cycling issue here.

A.
 
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