Main switch Isolator breaking capacity

I’m agreed with you that the symbol in the disconnector switch isn’t the one indicating overcurrent protection but in the technical data sheet said that it has a Ics of 6kA, this is quite awkward a disconnector switch has integrated it like in this ABB model. Anyway my last conclusion was that this disconnector switch needs to be degrading by ABB 100A E203 which provides the right short circuit breaking capacity Ics at 25kA or replace it by a different disconnector switch without any overcurrent device integrated on it.

But it does not need anything at all doing  if there is a fuse in the supply to it that limits the energy let-through to the equivalent of 6kA or less. A PSSC test will not tell you this -you need knowledge of what other ADS is upstream.

Mike.

mapj1 said:

But it does not need anything at all doing  if there is a fuse in the supply to it that limits the energy let-through to the equivalent of 6kA or less. A PSSC test will not tell you this -you need knowledge of what other ADS is upstream.

Agreed - What's important is the combination of protection, just in case you are making onto, or perhaps less likely breaking, a fault. Doubly important if the isolator can be operated by ordinary persons to get this correct !