DISTRIBUTOR CANNOT BE TRUSTED...

but any cover would have to have windows for the meters.

I will not be able to get information on the distributor arrangements unfortunately.

does anyone know any examples of someone installing an isolation transformer for an entire domestic household?

mapj1:

Are the local sockets actually Schuko (the USA ITA scheme calls that type 'F') or actually the Russian variant with the same hole spacing but thinner pins ?
Maybe these GOST 7396 type C ?    If you have suffered from jammed and burnt pins, that may be the problem, as the proper Schuko is a very reliable design in the mating socket, apart from the LN polarity not being preserved.  From East Berlin in the early 2000s   I remember the odd Russian socket being a pain as no modern appliance could be plugged in, but the Russian plugs were equally troublesome - making a rather half hearted flickery contact and overheating in the newer sockets,and poor build quality generally. There converting an old  2 pin socket to a new style one with earth was sometimes done with an N-E link on the back of the socket, when the old wiring in the wall was only 2 core.

I'd be very wary of that sort of TNC to the socket, or even creating a CPC from neutral in the TNC-s way at your CU origin. To make it  safe, great  care  is taken with PME distribution to avoid L-N reversal and open neutral incidents. That rigour would need to be extended to all the neutral connections inside and outside the building between you and the substation. Looking at the pictures, you would have to be very brave to assume this  - and given the shared neutral blocks and random colour nature of the hook-up, at some point when someone else is having wiring done, your supply will suffer !!

(In UK PME distribution, supply side all neutral joints are either double crimped or have some equivalent level of  redundancy, so that one failure cannot lead to danger. You will struggle to replicate that level of safety) 

Given the uncertainty about the earthing and the neutral, double insulated (Class 2) appliances are your best friend in such a case, and RCD protection for the unavoidable class 0 (i.e. Class 1 things that really should be earthed and are not).

Like Andy I think wiring to the letter of BS7671 may not be the best choice without a bit of adjustment - the UK standards assume neutral is at or near earth voltage, and that supply impedances will allow discrimination to work - neither may be good assumptions in the world centred around un-earthed 2 pin wiring.

And yes, our T and E with its bare earth, and the 32A ring final are not good choices in a country that presumably expects one combined power and socket circuit, and full size CPC.

The most useful thing you can do consumer unit wise is to have a double pole breaking RCD, and perhaps consider having the sort of thing that is done with 'power of opportunity' military boxes - where to be honest the sources of supply can often look a bit like this. Typically there  is a box that  monitors the incoming supply, to indicate that voltage, L-N polarity, and if required phase rotation are all in range as expected. Depending on the application a fault may just flash some warning lights to raise an alarm, or may operate a 'shunt trip' to throw the power off. Neutral earth voltage is a good one to monitor if you can. If there is any chance of an earth electrode, personally I'd go for that. Be aware that if your earth electrode is better than the one at the substation then an LE fault at your side may actually pull L1 nearer to true earth voltage and at the same time increase the neutral to terra-firma offset voltage for all other users of the substation.

Mike.

Are you able to provide examples of the ‘power of opportunity equipment’ and some more detail about the issues associated with the apartment earth electrode being better than the substation one? I am aware of an example where a friend in country had a better earth electrode installation at his house than the substation electrode - confirmed by the electrical inspectors…


Chris

I presume there's normally a cover - attached to those caged nuts.

I guess the first question is whether that Earth terminal is connected to the incoming N or not (I can't tell from the picture) - that might give us a clue whether it's intended to be TN or TT for starters.

Somebody seems to have tapped in an extra un-metered live, in green-and-yellow, from the incoming breaker, and fed it out the bottom of the panel alongside two earth wires.  Is this a sneaky way to hide abstraction?

There are main incoming meters at the entrance to the building which appear to monitor the usage for a group of apartments (as well as the individual meters). Seems as if the electric company are not so trusting and I don’t blame them in this maze of wiring. If this was a sneaky supply I would hope they would have caught it by now. In the meantime, let me try to track it down!

There are quite a few things that would be frowned upon in the UK, not least the use of GY for everything, but also the recombination of consumer's neutrals after metering, and a shared neutral to the 3 flats.


I also  presume the door does not lock...

The neutrals are combined (bolted together) before they enter each meter. The neutrals are shared to 3 flats. This neutral combines with more neutrals downstream through another 2 distribution panels until the main incoming cable to the building. The door locks with a triangle type key used on lampposts and gas meter covers.

On the subject of plastic and metal - Are UK consumer units still metal nowadays? I see a lot of plastic CUs floating about out here.

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