Zs

[comms]

Evening all,
Do I put down the Zs results for circuits on the electrical installation cert even if they don't meet dissconnection times in 7671.
Zs result tested from socket on ring is 13.28 ohm high as the system is TT, Mk split board cu 100A 100mA s type rcd as main switch & 30mA rcd for final ring circuits + shower.

Cheers all

 

[il78]

The reading does meet the requirements of BS:7671.

Circuits protected by a 100mA RCD / Max Zs permitted = 500 Ohms.
Circuits protected by a 30mA RCD / Max Zs permitted = 1666 Ohms.

The reading you got from the socket circuit is quite reasonable for a TT system.

 

[fencer]

Thanks il78