dangers associated with wiring earth to neutral in the consumer unit?

[overflow99]

First time on here.... Looking for your thoughts on my situation plz. I've a small apartment in Spain and recently discovered there is no earth in the building, which I'm nervous about. Firstly I purchased individual socket rcd's and put one in all 12 sockets. Don't even know if this is giving me any extra protection or not. There is, what I assume, is an rcd on the consumer unit. I've employed the service of an expat spark, recommended by a friend. He has run an earth connection to all sockets, returning to the consumer unit. We had discussed putting in an earth rod tt connection when I was last in Spain, which I was happy about, although where we are is built on rock, but he said he had a machine to place the rods. Now, on my return, he said the job was complete. When I checked there is no earth rods installed. I opened the consumer unit and the newly installed earth wires have been terminated in the same terminal as Neutral. A masking tape sticker has been placed saying Pme Tierra. To me it feels like I'm swapping one potentially dangerous situation for another. Am I overreacting? Also, what is the situation regarding my socket rcd's and the rcd on the consumer unit, will they act to save me or my Mrs in all situations. I've used a socket tester, (UK 3pin through a Spanish adaptor), and when positive pin goes to positive in the socket, the rcd test does trip the switch. But, if I turn it the other way round, positive pin to negative in the socket the rcd test doesn't trip the rcd. Is that normal? I identified which pin socket carries live and neutral btw so I can plug my UK items in the correct way round. Don't know if it makes a difference. Was going to ask him to put the originally agreed earth rods in, which would be just 6ft below our balcony to street level, but don't want to be that pain in the --- customer, if all is safe, as he seems a nice enough guy. Any thoughts on the safety aspect would be appreciated as I always like things done 100% right. Thanks in advance.

 

[overflow99]

Even thoughts on any part of the post would be appreciated. Thank you.

 

[littlespark]

The earth wire looks like its been connected to a live cable, not a neutral.

Do you have another photograph showing the straight on view, but with covers off? So we can see how the breakers are connected.

And give us a description of what each breaker switch does... (is one a mainswitch, controlling everything, and the others go out to circuits)

 

[overflow99]

The earth wire looks like its been connected to a live cable, not a neutral.

Do you have another photograph showing the straight on view, but with covers off? So we can see how the breakers are connected.

And give us a description of what each breaker switch does... (is one a mainswitch, controlling everything, and the others go out to circuits)

Thanks for your reply, appreciated littlespark. I've attached another couple of photos. 2 cables come in, a blue and a black from the mains. The other day a I put the multimeter across them and there was no voltage on the brown, but will recheck. In Spain there doesn't seem to be any adherence to colour codes.

 

[littlespark]

Looks to me like the supply in is the black and blue cables coming in from bottom right....
They go up to a double pole circuit breaker (20A) at the top, that then feeds the 25A RCCB below it.
Then goes through a 15A circuit breaker, and this exits through the back of the box. (only one circuit?)

I dont think theres much any of us UK based electricians can say about this... without knowing the regs....although i think one or two might have experience on spanish soil.

Im surprised the sockets are marked positive and negative.... thought they would be L and N

 

[overflow99]

Thanks for your reply, appreciated littlespark. I've attached another couple of photos. 2 cables come in, a blue and a black from the mains. The other day a I put the multimeter across them and there was no voltage on the brown, but will recheck. In Spain there doesn't seem to be any adherence to colour codes.

OK been checking with the multimeter. Firstly, all switches turn the electricity off. This is only a very small studio, with no bedrooms btw. The wires that come in the bottom are blue and black and arrive at the consumer unit via conduit from a dodgy look switch which is stuck behind a cupboard and says Main switch written on masking tape. The on off function of the dodgy looking switch does nothing. The black wire goes to the top left and the blue to the 2nd top left of the 3 +rcd switch terminal. Behind the single switch there is an exit point in the wall for the blue and brown wire. When bridging across from left to right on all switches there is zero V value. The top 2 switches can not work independently of one another. When bridging side by side going from left side or right side going down all show around 238V. When I turn the bottom single switch off and bridge across left, (where the earth wire is), to right it shows 230V but when switched on 0V. That's with the 4 above still in the on position. When they are off the value is also 0V on the single switch. Bridging across from left to right on the Rcd shows 9V when tripped and with the top 2 switches in the on position, even though electric is tripped off. The top 2 when off shows zero V. I bridged from the earth point at the brown wire to the earth connector in the round terminal box and it showed 0V. I'm pretty much at the limit of what I know electrically. Wondering about the safety implications of this set up, as will the rcd trip etc or even though we're on rock is TT viable /preferable, thanks.

 

[overflow99]

Looks to me like the supply in is the black and blue cables coming in from bottom right....
They go up to a double pole circuit breaker (20A) at the top, that then feeds the 25A RCCB below it.
Then goes through a 15A circuit breaker, and this exits through the back of the box. (only one circuit?)

I dont think theres much any of us UK based electricians can say about this... without knowing the regs....although i think one or two might have experience on spanish soil.

Im surprised the sockets are marked positive and negative.... thought they would be L and N

I think your path description sounds spot on and now I can visualise the path, thank you. I'm still puzzled about the earth wire joined with the brown wire. That earth wire goes straight up to the round junction box shown in the original post to join with all the earth wires coming from the sockets. What is being achieved here by doing this... I've attached another photo. Thanks.

 

[brianmoooore]

First of all, deriving a property's 'earth' terminal by connecting it to the incoming neutral supply wire is very common in the UK, and is known as PME or TNC-S, but this earthing terminal is provided by the supplying authority, subject to conditions, and relies on the incoming neutral being connected to an effective earth rod at the sub station and points in between.
I don't know the legality of an electrician making this connection himself where you are, but it appears that either he's strapped the earth to the incoming live (which isn't good) or the incoming polarity is wrong, and you have a single pole MCB connected in the neutral wire, which is also not good for other reasons.

 

[westward10]

I very much doubt we are going to be able to give a reasoned answer. Without being there and knowing the way things are done in Spain it is impossible to say.

 

[overflow99]

First of all, deriving a property's 'earth' terminal by connecting it to the incoming neutral supply wire is very common in the UK, and is known as PME or TNC-S, but this earthing terminal is provided by the supplying authority, subject to conditions, and relies on the incoming neutral being connected to an effective earth rod at the sub station and points in between.
I don't know the legality of an electrician making this connection himself where you are, but it appears that either he's strapped the earth to the incoming live (which isn't good) or the incoming polarity is wrong, and you have a single pole MCB connected in the neutral wire, which is also not good for other reasons.

Thanks for your reply Brian... I had read about PME TN-C-S and understood it's achieved by combining earth to neutral, which works well unless a break develops on the neutral return line then there could be problems with things going live or getting zapped. If the earth is tied to live that would be worse I'd imagine. When I check at the sockets Neutral to Earth shows 0V and Live to Earth 230V and Live to Neutral 230V. Which scenario would this indicate... Earth to Live connection or Earth to Neutral connection? Or could it be either? If the connection has been made on a self basis rather than approved by the the supply company is there any extra implication other than administrative and as the end user what do I need to watch for... Are rcd's going to work. Again appreciate your reply.

 

[overflow99]

I very much doubt we are going to be able to give a reasoned answer. Without being there and knowing the way things are done in Spain it is impossible to say.

Agreed... It's difficult to describe and show you and a different country's regs all adds to the difficulty.... Thank you

 

[overflow99]

I suppose if I boil it down, will rcd's protect us should things go bad or do I ask for TT supply, which may be hard to achieve on this rocky area .... Don't want to fry the wife, ( atm anyway ), or granddaughter... Thank you all, for your help

 

[Mike Johnson]

Getting a TT spike into rocky ground was nearly always overcome with a plate electrode the main problem was then getting two or three testing spike's into the ground for verifying Ω reading that aside putting the plate near a tree helped or even driving a spike with an SDS near a tree, necessity being the mother of invention.

Convention in the EU is that looking straight on at a socket face plate, phase should be on the right additionally all MCB's should be dual pole.

 

[pirate]

I have some experience with Spanish electrics. Some stuff is just awful...and some is very good indeed.
My advice is simply that you employ a Spanish electrician from a reputable company and have him/her check your system completely for safety. This is unlikely to be expensive because it's a small system and, from my personal experience, Spanish electricians are not expensive, having an hourly rate quite a bit lower than many in the UK.
Clearly you are concerned about this, rightly so, thus a proper check is essential. As I said, the cost will be reasonable, and the safety and peace of mind do not have a cost.

 

[overflow99]

Getting a TT spike into rocky ground was nearly always overcome with a plate electrode the main problem was then getting two or three testing spike's into the ground for verifying Ω reading that aside putting the plate near a tree helped or even driving a spike with an SDS near a tree, necessity being the mother of invention.

Convention in the EU is that looking straight on at a socket face plate, phase should be on the right additionally all MCB's should be dual pole.

Thanks Mike for your reply and info on the plate electrode, which may be the way to go. I've pushed the building administrator on getting an earth connection for the community but without success, which is why I got a spark in, as thought I'll get it done myself. Not sure I'm sleeping easier though.