substituion of HRC fuse in Vacuum Contactors
substituion of HRC fuse in Vacuum Contactors
(OP)
Hollo folks!
we are using vacuum contactors at 6.6 kv with HRC fuses.In case we use a circuit breaker in series with the vacuum contactor having instantaneous over current protection then is it possible to avoid the usage of HRC fuse.If yes why.If we dont use any fuse then will it withstand thermally the fault current.
VC can thermally withstand 9000 Amp for 1 second.
Fault current may be taken as around 15KA and this much current will flow for the time till over current relay operates and the breaker trips.
we are using vacuum contactors at 6.6 kv with HRC fuses.In case we use a circuit breaker in series with the vacuum contactor having instantaneous over current protection then is it possible to avoid the usage of HRC fuse.If yes why.If we dont use any fuse then will it withstand thermally the fault current.
VC can thermally withstand 9000 Amp for 1 second.
Fault current may be taken as around 15KA and this much current will flow for the time till over current relay operates and the breaker trips.






RE: substituion of HRC fuse in Vacuum Contactors
What if the upstream relay or breaker fails? The manufacturer will have no liability if your contactor fails due to unauthorised modifications and your insurance company may also be interested in the matter.
RE: substituion of HRC fuse in Vacuum Contactors
Christopher Caserta
Sr. Regulatory Engineer
ccaserta@enorthhampton.com
Ph:904-225-0360
Fax:904-225-0340
RE: substituion of HRC fuse in Vacuum Contactors
Bung