DIY Doctor UK DIY Forums

I'm not an electrician.

We've just updated our electrics and I'm told we can get our safety certificate (because we have RCD's - I think that's what our electrician said) but with a warning that the earth loop / FE is too high a reading.

My ignorance tells me this is the feed from my electrical supply company into the house so the electrical company should be responsible for correcting this?

The current reading is 1.6 Ohms, we have a TNS system. The recommended reading is 0.8 Ohms.

Is someone able to advise if I can ask he electrical supply company to correct this at all? Or, is this something I'd have to get someone in to do for me?
Thanks

Yes the DNO should be told. However you don't really have the option to select the earthing method. They could simply say sorry we can't offer and earth you need to move to a TT earth.

Likely there is a fault which they will correct, with the TN system we have TN-S as you say max 0.8 ohm and TN-C-S with max of 0.35 ohm. With TT looking at better than 200 ohm typical around 50 ohm.

With RCD on all circuits not really a problem. What is of interest is the prospective short circuit current, looking at around 500 amp, below that there is a good chance the volt drop is over the limit.

If you have been supplied an earth by the DNO, they have responsibility to maintain it!