"17 edition"consumer units still being sold.

Andy are you suggesting that a short to case after a rectifier makes a DC fault?

No, I'm suggesting the fault current will be something other than a pure sine-wave.

 

First the fault current available is on average half the PSSC

An earth fault on a TT system? I very much doubt that.

 

This will not trip the CPD I suppose!

Yes, I very much doubt that a overcurrent CPD will trip on a earth fault of any kind on a TT system.

 

Also it is not a DC fault, hence my comment above about smooth and continuous DC, because a single rectifier will give an AC fault current which WILL operate the RCD.

Again I suggest you look at Fig A53.1 - according to row 3 a half wave rectified earth fault current is NOT guaranteed detectable by an AC type.


   - Andy.

Andy are you suggesting that a short to case after a rectifier makes a DC fault?

No, I'm suggesting the fault current will be something other than a pure sine-wave.

 

First the fault current available is on average half the PSSC

An earth fault on a TT system? I very much doubt that.

 

This will not trip the CPD I suppose!

Yes, I very much doubt that a overcurrent CPD will trip on a earth fault of any kind on a TT system.

 

Also it is not a DC fault, hence my comment above about smooth and continuous DC, because a single rectifier will give an AC fault current which WILL operate the RCD.

Again I suggest you look at Fig A53.1 - according to row 3 a half wave rectified earth fault current is NOT guaranteed detectable by an AC type.


   - Andy.