Dear Colleagues:
Thanks again for all the terrific advice!
dpc, I had already found that paper on the Internet, and maybe I just don't have the background to understand it, but it didn't seem to help too much. But thank you for trying to locate info for me!
redtrumpet - the Schneider site...
First of all, thanks to everyone for your advice and expertise!
I have only been with my company for three years, so I don't know a lot of the history behind our breaker replacement program. It is my understanding that there have been some problems blamed on charging current interruption, but...
We have a number of older oil breakers at subtransmission voltages (69 and 115 kV) which are being systematically replaced due to their being unrated for charging current interruption. We also re-evaluate line charging current whenever a portion of an overhead subtrans line gets converted to...
Why is it that a circuit breaker can interrupt thousands of amps of fault current, but not a few dozen amps of charging current? I understand that charging current - which is capacitive and more or less 90 degrees out of phase with load current - can arc across circuit breaker contacts. But...
