Capacitor bank switching problem
Capacitor bank switching problem
(OP)
Dear All
Following is a problem, Can anyone help
1800kVAR,6.6kV Capacitor bank when switched on through a vacuum contactor rated 11kV,400A,AC4 gives a loud noise like a gunshot.remains energized normally and when swithced off same thing happens.
No visible marks of insulation oil leakage on the capacitor bank, no damage to insulator.
Do i need to check the switching chamber of the contactor,if yes at what voltage.It is under operation since 1995 but was last swithced on a year ago.
What else to look for?
Same thing happens to the stage 3 bank but with lesser sound
Thanks to anyone who can solve the mystery.
Following is a problem, Can anyone help
1800kVAR,6.6kV Capacitor bank when switched on through a vacuum contactor rated 11kV,400A,AC4 gives a loud noise like a gunshot.remains energized normally and when swithced off same thing happens.
No visible marks of insulation oil leakage on the capacitor bank, no damage to insulator.
Do i need to check the switching chamber of the contactor,if yes at what voltage.It is under operation since 1995 but was last swithced on a year ago.
What else to look for?
Same thing happens to the stage 3 bank but with lesser sound
Thanks to anyone who can solve the mystery.






RE: Capacitor bank switching problem
Is the contactor specifically intended and rated for capacitor switching? Have insulation-resistance—specifically bottle vacuum integrity—been performed with satisfactory results?
Contactor-manufacturer’s application and maintenance literature, along with NETA 2001 Maintenance Testing Specs may be useful references.
RE: Capacitor bank switching problem
Visit
http://www.jenningstech.com/pdf/cont/rp173.pdf
for a sample of Capacitive MVAR rating of a vacuum contactor
RE: Capacitor bank switching problem
RE: Capacitor bank switching problem
1. Where is the physical source of the noise. The Cap or the VCTT?
2. Are the Caps connected in Wye or Delta? If in Wye, are they single or double bushing? If single bushing, is the bank effectively grounded?
3. Do you have a series reactor in line with the Cap bank?
4. Are all electrical connections in this circuit (cables, lugs, bolts, etc...) mechanically sound?
GH