Cable limiters
Cable limiters
(OP)
My experiences with cable-limiters is in reducing cable degradation due to potential subsequent cable fault conditions and to provide greater system reliability in electrical distribution network-protector system designs.
I am aware of the fact that cable-limiters may also provide reduced available fault-current values to downstream electrical equipment. I am not familiar with how to accomplish this. I do not know how affective or to what degree they may reduce the fault currents. I suspect there are a lot of variables to consider (conductor type, size, length, number or paralleled conductors per phase, available fault currents versus allowable fault currents).
Any assistance would be much appreciated in the application of cable-limiters for the purpose of reducing fault-current values is systems less than 600 volts.
I am aware of the fact that cable-limiters may also provide reduced available fault-current values to downstream electrical equipment. I am not familiar with how to accomplish this. I do not know how affective or to what degree they may reduce the fault currents. I suspect there are a lot of variables to consider (conductor type, size, length, number or paralleled conductors per phase, available fault currents versus allowable fault currents).
Any assistance would be much appreciated in the application of cable-limiters for the purpose of reducing fault-current values is systems less than 600 volts.






RE: Cable limiters
The Bussman or Ferraz Shawmut websites can provide a lot of detailed information on the functioning of current-limiting fuses.
Like a fuse, the cable limiter can only limit current by melting and clearing a fault within the first 1/2 cycle. For longer clearing times, it is not current-limiting. Also, for very high amperage feeders with multiple conductors per phase, the limiters will probably not help much in reducing downstream fault current.
Also, if you are trying to use a cable limiter to protect a downstream circuit breaker, this is only possible if the cable limiter and breaker are a tested combination, and I don't think there are any tested combinations involving cable limiters, so from a Code compliance point of view, you are probably out of luck.
RE: Cable limiters
Just a few thoughts, hope it helps.