Zoomup:
If the Ra is about 200 Ohms an L to E fault current is restricted in magnitude. And the 30 mA R.C.D. is still very swift in disconnecting the fault.
Z.
If the earth fault current is limited then I agree there's far less of an issue. Ra alone doesn't guarantee that though - bonding to metallic water or gas supplies can re-introduce a low impedance path (via neighbouring TN installations), so potentially bring prospective earth fault currents back up to TN levels.
- Andy.
Zoomup:
If the Ra is about 200 Ohms an L to E fault current is restricted in magnitude. And the 30 mA R.C.D. is still very swift in disconnecting the fault.
Z.
If the earth fault current is limited then I agree there's far less of an issue. Ra alone doesn't guarantee that though - bonding to metallic water or gas supplies can re-introduce a low impedance path (via neighbouring TN installations), so potentially bring prospective earth fault currents back up to TN levels.
- Andy.
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