Short circuit current& No. of operations relation
Short circuit current& No. of operations relation
(OP)
Hi
Can any one help me to find the relation between the withstand short circuit current and the number operations relation for vacuum and SF6 medium voltage circuit breakers.
For example if I have circuit breaker with 31.5 kA at the manufacturing date (No. of operations = zero), what will be the withstand short circuit current after 2000 operations.
Thanks
Can any one help me to find the relation between the withstand short circuit current and the number operations relation for vacuum and SF6 medium voltage circuit breakers.
For example if I have circuit breaker with 31.5 kA at the manufacturing date (No. of operations = zero), what will be the withstand short circuit current after 2000 operations.
Thanks






RE: Short circuit current& No. of operations relation
RE: Short circuit current& No. of operations relation
RE: Short circuit current& No. of operations relation
DS 600 V air breakers is something we do somewhat often during electrical maintenances. I've seen some of these built in 1980 in pretty good shape.
RE: Short circuit current& No. of operations relation
RE: Short circuit current& No. of operations relation
I thought the number of maneuvers listed in the manufacturer's catalogs was based on full current making and breaking.
If you close the breaker (by chance) when the sine wave is at zero, then this maneuver practically do not count.
If an MV breaker is free standing and not connected (yet), then arming the lever and engaging / disengaging can only wear out the springs, which is not very critical as in these will wear out after the number of maneuvers has passed.
Note that Merlin Gerin SF6 circuit breakers are rated for 10,000 operations, 5 times more than the above mentioned 2,000 which may be based on other rating standard.
If the above is correct, then there is no derating on the current carrying capacity of the breaker. If the above is not true, please correct me.
RE: Short circuit current& No. of operations relation