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Capacitive discharge vs batteries in breaker operation

Capacitive discharge vs batteries in breaker operation

Capacitive discharge vs batteries in breaker operation

(OP)
Hi there. I an unfamiliar with capacitive discharge on medium voltage breakers and their pros and cons vs using batteries on MV breaker operation. I was always under the impression that if power were lost you you can operate the breakers and meters under battery power.

Thanks.
b

RE: Capacitive discharge vs batteries in breaker operation

Are you aware that batteries cost to maintain? Where capacitors, if treated correctly can last as long or longer with much less maintance.

The down side is they don't power microprocassor relays very well.

But the capacitors can be charged by a station power source, or by CT current.

There were some microprocessor relays made outside the US that not only could be operated with batteries (only station power and CT current), and provide tripping capacitors internally. Not sure how they would work with US made breakers however.

RE: Capacitive discharge vs batteries in breaker operation

Plus, capacitors only supply tripping coil current, they cannot recharge a motorized charging mechanism so that the breaker is ready to be reclosed when power returns. In some critical applications, even a few seconds of charging time can be costly.

"Will work for (the memory of) salami"

RE: Capacitive discharge vs batteries in breaker operation

Maybe that's why the breakers used compressed air, or AC powered spring charge motor. On the distribution system the reclosing speed is not as important.

Besides if station power does not return following a breaker operation, then there is no need to close the breaker.

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