Equipment SCA and protection
Equipment SCA and protection
(OP)
Electrical equipment often has a "Short Circuit Amps (SCA)" rating. If the available SCA exceeds the equipment's rating, but the upstream protective device to this equipment is sized to operate at a value less than the equipment's SCA rating, is this acceptable?
Thanks
Thanks






RE: Equipment SCA and protection
RE: Equipment SCA and protection
This is contrary to the UL series rating rules on Low Voltage equipment. I have not gotten what I consider good scoop on this but I have seen it a number of times in studies from these reputabe companies ?
JIM
RE: Equipment SCA and protection
RE: Equipment SCA and protection
Another option is installing current-limiting reactors. This lowers your available short-circuit current, increases your voltage regulation and is a more significant cost to consider. It will require you to rework your short-circuit study too.
RE: Equipment SCA and protection
You can install current-limiting fuses upstream but again they must be a test combination with the breakers you are trying to protect. If the fuse is too large, it won't help. The breaker manufacturer should be able to give you information on what current-limiting fuses would work.
RE: Equipment SCA and protection