Tuesday, 12 July 2011

Three Phase RCDs

My previous post raised some questions on how does a three phase RCD work. If you've a three phase load then you can't just use three single phase RCD's attached to each of the phases. You'll need a specialist 3 Phase RCD such as this one from HSS.

Basically it works in the same way as a single phase one in that it's looking for a mismatch in current in and current out. It uses a "Core balance Current transformer" to sense this mismatch.

1 comment:

Anonymous said...

Thanks for that.

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