TNCS 6mm main earth - EICR

Ah sorry, I highlighted for 60A - we need to look at more like a 600-650A fault current on a 60A curve, to see roughly what 850A would do on an 80.

I reckon with a squint it could be nearer half a second, though I don't have an 80 A curve.

One of the things with fuses, as opposed to MCBs, is that the degradation in breaking time with falling fault current is much smoother variation- a breaker will either do a near instant trip, or you are relying on the much slower thermal part, so there is a hard limit, and at fault currents below that  'it's all off in a heartbeat' is not true. (and for ADS for safety of life its getting it off in a fraction of a heartbeat time that matters.)


Also in any case from the adiabatic point of view there is no problem with the single insulated 6mm. 


The thing that has increased the recommended size of earth conductors, and main bonding, is concerns about diverted neutral current, for which you the company fuse will not operate, and nothing will prevent a long term overheating.

Ah sorry, I highlighted for 60A - we need to look at more like a 600-650A fault current on a 60A curve, to see roughly what 850A would do on an 80.

I reckon with a squint it could be nearer half a second, though I don't have an 80 A curve.

One of the things with fuses, as opposed to MCBs, is that the degradation in breaking time with falling fault current is much smoother variation- a breaker will either do a near instant trip, or you are relying on the much slower thermal part, so there is a hard limit, and at fault currents below that  'it's all off in a heartbeat' is not true. (and for ADS for safety of life its getting it off in a fraction of a heartbeat time that matters.)


Also in any case from the adiabatic point of view there is no problem with the single insulated 6mm. 


The thing that has increased the recommended size of earth conductors, and main bonding, is concerns about diverted neutral current, for which you the company fuse will not operate, and nothing will prevent a long term overheating.