Earthing in Spain

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PhilTilson

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Would appreciate advice from an expert in earthing systems.

My installation here in Spain is (I believe) a T-T system - overhead single phase power supply, only earth is at the consumer unit. This is a very good earth, connected to about 200m of reinforcing rods in the house foundations.

However, I suspect that the neutral supply line is not grounded at all, anywhere, as there is around 60v between neutral and earth within the house. This does not present much of a practical problem, but I would prefer it to be 0v!

So the question: Could/should I earth the neutral at either the consumer unit or the pylon/electricity meter (about 200m away) or both?

I am wondering if doing so might also help with nuisance tripping of the RCD during windy/stormy conditions.

Thanks
 
Probably no-one familiar with spanish distribution systems!
It might be better to have a word with a spanish electrician and see what they say.
 
It looks that way. :) Although there have been other questions on the subject that have attracted responses.

It's not really so much a question of Spanish earthing, as earthing techniques in general. What I am really wondering is if there would be any adverse effect were I to earth the neutral of the incoming supply at the pylon (which is also where my electricity meter is).

I don't really want to bring down the entire local area's supply!

Phil
 
PhilTilson said:
However, I suspect that the neutral supply line is not grounded at all, anywhere, as there is around 60v between neutral and earth within the house. This does not present much of a practical problem, but I would prefer it to be 0v!
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I've never measured N-E potential on a TT system.

Theoretically could it reach 60v - I suppose it could but whether it actually would... :?

But if you were to link the earth & neutral here I think you would create a TN-C-S earthing system which is a job best left to the DNO. Also if there was a neutral break in this case then surely it's possible that the entire network downstream of the break could "earth" through your house's foundations. :shock:

PhilTilson said:
I am wondering if doing so might also help with nuisance tripping of the RCD during windy/stormy conditions.
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I don't see why a storm would necessarily trip your RCD though. This detects a L/N imbalance so if it trips periodically it suggests that you could have a L/E or N/E fault somewhere. Or maybe some sort of voltage fluctuation? :?

PhilTilson said:
Would appreciate advice from an expert in earthing systems.
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Expert? I'm not even a novice. :lol:
 
I don't see why a storm would necessarily trip your RCD though. This detects a L/N imbalance so if it trips periodically it suggests that you could have a L/E or N/E fault somewhere. Or maybe some sort of voltage fluctuation?
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It's a very common occurrence out here. Most people living out in the sticks get this problem during very windy or stormy weather, along with dozens of 'mini-cuts' lasting from less than a second to several seconds. Really irritating! :?
 
Had a seach of the net and all I could find was this or this similar problem to the symptoms you have.

Alot of people seem to agree that while an RCD shouldn't trip with problems upstream, sometimes it may. However, nobody seems to be entirely convincing with their agument as to what has caused it! :lol:

Theoretically I can't see how an upstream problem on a TT system could cause it to trip.

But like I said earlier, i'm no expert. :lol:
 
A TT system relies on an RCD and an adequate return path to the transformer. A 60v reading between N & PE is not exceptional ,as they are at different potencials. I would advise you to loop test your PE and carry out an RCD test at the rated mA. Tripping during high winds is a problem in Spain, I had a similar experience in the UK it was caused by poor connections on overhead lines. Connecting N to PE will not eradicate the problem.
 
stevehilling1953 said:
A TT system relies on an RCD and an adequate return path to the transformer.
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Surely the neutral is supplied by the transformer along with the phase? Wouldn't any earth fault return straight to earth and not back via the transformer - is this what you mean?

stevehilling1953 said:
Tripping during high winds is a problem in Spain, I had a similar experience in the UK it was caused by poor connections on overhead lines. Connecting N to PE will not eradicate the problem.
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This goes back to my last post - it seems quite common that people have this problem (as you state loose/poor connections seems a common theme). But i'm still confused as to how an upstream fault can cause the RCD downstream to trip? Like I said, in theory this isn't possible but in practice... :lol:
 
Neutral is obtained from the centre point on the transformer, centre point is also grounded to earth via a rod at source. Your reading at the property to earth I would expect to be in excess of 100 ohms, hence the differing potentials. Have you carried out a insulation resistence test on your property,if you have and there is a fault neutral to earth this would account for nuisance tripping due to poor connections external to your property.
 
@Phil if you have tested completely and verified that the voltage between Neutral & Earth is over 12V then call Endesa to revise it as it´s not for you to manipulate.


@Steve all TT earthing arrangements in Spain should have a reading of less than 30 ohms.
 
stevehilling1953 said:
Have you carried out a insulation resistence test on your property,if you have and there is a fault neutral to earth this would account for nuisance tripping due to poor connections external to your property.
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I agree that a N/E fault could cause RCD tripping but the OP states that it is in windy weather.

As mentioned in an earlier post i'm confused as to how problems upstream could cause RCD tripping downstream. :?
 
I assume you have a poor neutral connection external to your property. Also you quite likely have a N - E fault internal to your property, do an insulation resistence test, if clear approach your supplier and ask him to rectify the external problem.
 
ho ho ho contact your supplier some people mention well____the local spark? around where i live was a farmer 12 yrs ago he is also a plumber , gas fitter and what ever else you may think of!!! i have been called to many of his bodges and would say a 2nd year apprentice in the uk would more savvy!!!
 
aguacaliente said:
ho ho ho contact your supplier some people mention well____the local spark? around where i live was a farmer 12 yrs ago he is also a plumber , gas fitter and what ever else you may think of!!! i have been called to many of his bodges and would say a 2nd year apprentice in the uk would more savvy!!!
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He could end up in "hot water" hey agua? :oops: :lol:
 
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