- Reaction score
- 2,069
Not 100% selectivity no, but better than with SP.
Also DP or SPSN RCBOs would allow the upstream RCD to be reset after it trips on a N-E fault whereas with SP RCBOs you could be stuck with the whole installation being off.
Nobody is arguing that DP isn't a better option.
You could also have the whole installation off using DP rcbos, dependent on where the N to E fault was, I've seen N to E faults cause random rcbos to trip.
Also, regardless of whether Dp, Sp TT or Tn is used the fault will still remain.
Are DP rcbos a requirement ? NO
Are DP rcbos needed ? NO
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