Meter Board

Designmen90 · Nov 14, 2020

If I get 4x70mm2 from substation to my Meter Board, and then I have N and PE busbar, should I install 3ph SPD or 3Ph+N (surge protection device), because it's TN-C-S?
The N and PE busbars are bridged in board. If I install 3Ph+N and overvoltage occurs on one of the L1,L2,L3 phases I'm afraid that overvoltage will through bridged PE come to N busbar and then though house installation. Please help me if I'm wrong? Thank you!

loz2754 · Nov 14, 2020

Why is the protective earth connected to neutral in your DB?
Surely this would make it a TNC which is not allowed by the ESQCR.

Edit: just noticed you're not in the UK. Perhaps the regulations allow it where you are.

Designmen90 · Nov 14, 2020

loz2754 said:
Why is the protective earth connected to neutral in your DB?
Surely this would make it a TNC which is not allowed by the ESQCR.

Edit: just noticed you're not in the UK. Perhaps the regulations allow it where you are.

3phases and PEN comes from substation and in DB they are seperated, so it makes TN-C-S system.