DISTRIBUTOR CANNOT BE TRUSTED...

An interesting project.


Firstly I think I wouldn't assume anything as far as the supply is concerned. That might mean you can't just apply BS 7671 blindly - as the UK wiring regs (and standard practice) make certain assumptions about the supply - e.g. that the N is reliably at or about Earth potential - just for one example.


Local regulations/legislation/practice might also actually prohibit some of the more 'interesting' UK practices (reduced c.s.a. c.p.c.s, uninsulated c.p.c.s., or ring circuits for instance). I'd guess you'd probably want to stick with the local socket format (probably Schuko/Type F) too rather than BS 1363 13A ones for convenience of being able to use locally sourced appliances - which strict adherence to BS 7671 doesn't make easy.


The lack of an earth might not be as much of a problem as it first seems to UK eyes. Much of the continent traditionally used a mix of double/reinforced insulation and earth-free locations, which even in western Europe often resulted in simple unearthed 2-pin (type C) sockets in the majority of rooms - ones with earth contacts (type E or F) only been seen in 'wet' locations such as kitchens and bathrooms. It's only in the last perhaps two or three decades that earthing on all sockets has become the norm - and there weren't any great big piles of dead bodies before that.  I gather that in many part of Eastern Europe prior to the 1990s that TN-C "to the socket" was common too - i.e. both N and PE contacts of the socket were connected to the supply cable's N - so you perhaps can't even deduce a lack of earthing from the lack of a c.p.c.. That sort of thing also calls into question other UK practices such as DP switching and even the use of RCDs.


All in all I think some care is going to be needed to blend two different systems together. Some non-electrical precautions - such as going for plastic rather than metallic plumbing - may provide a greater level of safety than just trying to apply BS 7671 alone.


  - Andy.

Aren't those bare incoming terminals just wonderful!


There seems to be no reliable earth, and even if there were, what are the arrangements at the transformer?


You only have 32 A to play with. I wonder whether you should use an isolating transformer?

Thanks Andy! I’ve seen your name pop up all over this forum.


Ok so to give a bit more information - I have lived in Azerbaijan for 5 years now and my experience of living in multiple non-earthed domestic apartments has not been great from being shocked from faulty unearthed underfloor electric heating when coming out of the shower (traced back to a ’spare’ breaker), live walls and bathroom metalwork after a water leak, unearthed AC units and horrendous electric fields coming off of computer equipment when working from home (shown on my TriField TF2 meter - I am big on EMF).


With regards to unearthed sockets, unfortunately they are used all over some local apartments (Type C even in wet areas and no RCD protection in the apartment I am in now, fitted out around 10 years ago...), I am even considering bonding my laptop to the radiator to avoid all-day electric field exposure as there is no earth any of the Type C sockets - this is another topic so let's avoid that discussion! With regards to socket types, I have had multiple Europlugs breaking and live pins sticking out the socket so really want to avoid these especially with a baby in the house. Also want to avoid non-earthed sockets for above reasons.


I am actually considering using BS 1363 13A plugs and sockets throughout the apartment although I will need to avoid the 32 A ring circuits as the distributors breaker is also 32 A. I would need to change these out if we ever sold the apartment though.


Interesting point about the TN-C "to the socket”. Unfortunately this is not common practice in this location at least nowadays i.e. my previous rented accommodation in a brand new apartment block which had 2C+E cable installed throughout, simply had the earth core cut back making it too short to install at the sockets (even in wet areas!) otherwise the electric field exposure would not have been such of an issue.


Also interesting about the pipework - I was considering having an isolation flange installed on the water and gas pipes which need to be renewed anyway, if these became an issue… I actually get a nice zap when touching different pipework in the attic…definitely an interesting project!


Regards,


Chris

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.

I just seen the foto of the main intake  is it me or are they using green/yellow as a phase conductor very naughty

Well I thought our own Part P might stop a few "joiners who know electrics" using the green yellow conductor in as flex as a Ph switchwire but I don`t think it`s had great success !

Just because it would be a C1 here, does not mean that it is considered dangerous in other countries ?


If it was inside  a DNO substation with limited access then pre-meter bare metal like that might be just about OK here - there are a few scary 'skeleton units' still in use, but they are being phased out over time. It does make a mockery of the seals on the meter terminals, as abstraction needs little more than croc clips.


I assume the unmetered GY from phase 1 is a sub-main to another similar board.

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...