UK EICR upgrade question

Duncanf8 · Oct 19, 2020

Do an EICR and possible upgrade question! Domestic premises, TNCS, ZE 0.34 (yes quite close to max!) main fuse 60a and at some point the CU has been moved from garage to indoors, approx 8 meters away. No fused isolator 25mm tails and 10mm main earth.
So I put the main earth as a C3 and the absence of a fused isolator as a 2. I have put in a fused isolator and am not sure whether I have to upgrade main earth or not?
Second question, there is a switched fused spur in zone 2 used as a fan isolator. I could move it 600mm so it is outside the zone and blank off the original. Or could I just block off the feed and supply and rely on the circuit breaker fir isolation?
Thanks

westward10 · Oct 19, 2020

The earthing conductor has now become a cpc so verify using the adiabatic equation. 10mm would be the minimum size to support main protective bonding if that is terminated at the consumer unit.

telectrix · Oct 19, 2020

problem with fitting fused isolatoer is how to achieve discrination with the 60A DNO fuse. as for the FCU in zone 2, i'd mark that down as a C3 provided it has not suffered from steam ingfress and the bathroom circuits are all RCD protected. then leave it alone.

Duncanf8 · Oct 19, 2020

I could swap the 60 for a 80 at the mains and put a 60 in the isolator? Or leave both at 60?
No RCD on lighting circuits so need to do something with it!

telectrix · Oct 19, 2020

Duncanf8 said:
I could swap the 60 for a 80 at the mains and put a 60 in the isolator? Or leave both at 60?
No RCD on lighting circuits so need to do something with it!

if you don't alter anything in the bathroom, then you need not fit an RCD, just code it accordingly. C3 if supplemantary bonding is in place: C2 if not.