iam renovating my property in bulgaria and have noticed that the bulgarian wiring system on a ring main is 2.5 earth .phaze and nutural , iam wondering why do we have 1.5 cable on our earthing system as there cable will surely change my readings,
A bit late to the party, I know, but: The Bulgarian regulations are for a two-wire system, phase(live) and neutral. Neutral is tied to earth at the supply posts outside the house, and each socket should have a tiny wire link connecting earth to neutral inside the socket. This way each socket is earthed via the neutral.
Many e-pats, me included, rewire their houses with three-core cable (that awful ribbon cable) running a separate earth circuit back to the distribution board (Hah! two bottle-fuses and some twisted wires
). That earth circuit still has to be tied to the neutral in the dissy box. The reason the BG earth conductor is 2.5mm is that, in a fault condition, it has to carry enough current to blow the radial circuit fuse, the same current that the neutral conductor would carry if it was wired 2-core.
There is an inspection and certification system, which is supposed to be compulsory for new builds and renovations, but if you don't ask for it, the authorities won't come looking. However, an ex-pat friend rewired his renovation 3-core, ring mains, split load box, three pin plugs, the lot, then was daft enough to ask for an inspection. EVN (the supplier) condemned it on the spot, withdrew his supply and refused to reconnect until it was redone to BG regs. Why: because a BG electrician coming to service, faultfind, whatever, expects the system to be wired to the local regs, however inferior they may be.
I'm in the South East, Near Elhovo, EVN is my supplier, others eON etc may not have the certification system.
