After some advice: Mild tingle from shower when in use

[EFLImpudence]

I'm in Bournemouth.

It's winding me up to be honest!! The guy left me his number, so I just phoned him, he is saying he doesn't need ot do an IT test because he found no leakage to earth.

I don't understand that. It may be true that he didn't find any significant voltages in places they shouldn't be - but the way (really the one and only definitive way) to determine whether there are any 'leakages to earth' is to undertake IR tests!

Could he have clamped the tails (supply cables) or the light circuit and found there was 'no leakage'?
Unusual for there to be none on the tails.

Of course, he may not be brilliant and could have clamped the CPC (earth wire) mistakenly thinking that's how it is done.

Did neither of the electricians at least suggest some (more) bonding?
I am remembering that on one test there was five volts between shower and waste yet none between radiator and waste.

 

[JohnW2]

...it would make me rest easier if he actually carried out the IR test, despite his insistence that it probably won't show anything, and if it did it might be a fault elsewhere not related to the shower (which to my mind is still something that makes the test worthwhile!!!), he has agreed to come back and carry out an IR tomorrow, he can't do it today because he's got other jobs.

He does at least sound fairly 'willing'. As I've said, I think we all suspect that the IR tests probably won't show anything - but, as also has been said, they really ought to be done. It still seems a little odd that he didn't do the tests, and feels that they will not show anything, even though it was he who suggested the problem could relate to water in a JB!

So, if anyone has any final theories or tests they can imagine will help, please do throw them at me in case he can do them!

It might be worth suggesting that he does IR tests on "any conceivably relevant circuit", and not just on the lighting circuit which you have felt could be implicated.

As ever, thank you for your contributions, apologies for my slightly irritable last few posts!

No need to apologise - I think you have been more than adequately 'provoked'!

Kind Regards, John

 

[JohnW2]

I'm in Bournemouth.

That sounds fairly close - is it 'close enough'?

Could he have clamped the tails (supply cables) or the light circuit and found there was 'no leakage'?
Unusual for there to be none on the tails. ... Of course, he may not be brilliant and could have clamped the CPC (earth wire) mistakenly thinking that's how it is done.

Yes, I suppose any of that is possible. However, as I keep saying, what surprises me most is that he apparently suggested that the problem might relate to water in a JB but, despite that, did not do any IR tests (instead talking about ripping up floors to investigate).

Did neither of the electricians at least suggest some (more) bonding? I am remembering that on one test there was five volts between shower and waste yet none between radiator and waste.

Good question, but there might be an issue of 'what to bond to', and how. As I understand it, this 'waste' is just a metal surround/flange/whatever-one-calls-it connected to plastic waste plumbing. Even if it didn't sound like a pretty crazy thing to do, how would/could one bond to that?

Kind Regards, John

 

[bernardgreen]

Could he have clamped the tails (supply cables) or the light circuit and found there was 'no leakage'?

Unless there was some one there in the shower being tingled the leakage would not be there to be found.

It has to be a search for the source of the voltage difference that pushes the tingle produceing current through the person in the shower.

 

[JohnW2]

Unless there was some one there in the shower being tingled the leakage would not be there to be found. It has to be a search for the source of the voltage difference that pushes the tingle produceing current through the person in the shower.

I think we're probably talking about different types of 'leakage'. The possible 'leakage' (due to a pd which shouldn't be there) through the OP to create a 'tingle' (not even felt through intact skin) is probably too small to be measurable by any normal method - and, as you imply, would only be there to measure if someone was in the shower and experiencing a tingle at the time.

However, the latest electrician seems to have suggested (probably though lack of anything else to say!) that the problem could be due to water in a JB. I find that extremely unlikley, on a number of levels, but if it were the case it would result in a relatively constant 'leakage' (or potential leakage), at least when the JB was 'live', which one would expect to be reflected in the IR measurement.

Kind Regards, John

 

[TheGovernor]

I'm in Bournemouth.

I'm actually in Hythe (just over the Forest), small world

Could he have clamped the tails (supply cables) or the light circuit and found there was 'no leakage'?
Unusual for there to be none on the tails.

I'll try to explain in words what he did EFLI, he unscrewed the light rose and put a probe to earth, then he got two other probes and presumably measured between L/N, this was when he said there was 1v leakage on that circuit but he expected it considering the size of the circuit...

Of course, he may not be brilliant and could have clamped the CPC (earth wire) mistakenly thinking that's how it is done.

I think I may have just described that he did the incorrect test? To be fair I wasn't stood there the whole time...

Did neither of the electricians at least suggest some (more) bonding?
I am remembering that on one test there was five volts between shower and waste yet none between radiator and waste.

That's correct, no voltage between shower and rad (did I do waste to rad, I can't remember offhand, I'll check it).

The first guy suggested bonding all the pipework in the airing cupboard between all the various pipes (there are quite a few), no suggestion of additional bonding in the bathroom, although bear in mind it does it in both showers, which might suggest the problem is "further back" the chain as it were (this is where I think his "your shower is leaking" theory breaks down, because it happens in two different rooms).

 

[EFLImpudence]

Did neither of the electricians at least suggest some (more) bonding? I am remembering that on one test there was five volts between shower and waste yet none between radiator and waste.

Good question, but there might be an issue of 'what to bond to', and how. As I understand it, this 'waste' is just a metal surround/flange/whatever-one-calls-it connected to plastic waste plumbing. Even if it didn't sound like a pretty crazy thing to do, how would/could one bond to that?

Obviously the plastic waste cannot be bonded but there must be a good few ohms between the shower and the radiator pipe so, presumably, the shower is not sufficiently bonded.

 

[EFLImpudence]

Ah, I may be confused.

I was thinking there was no voltage between the radiator and waste.
None between radiator and shower is how it should be.

 

[Jackrae]

Re your query on the worth of bonding the shower outlet drain :-

On the basis that the voltage tingling you is coming from the shower valve and/or hose, and you are standing in a pool of water that is intimate with the metal outlet collar, then bonding the collar to the shower valve will eliminate any potential between them and so stop the tingle.

BUT, that doesn't necessarily eliminate the original problem - it only alleviates the effect on your body.

 

[TheGovernor]

Ah, I may be confused.

I was thinking there was no voltage between the radiator and waste.
None between radiator and shower is how it should be.

Mate, with this issue I'm not surprised you got a bit confused My head is swimming with it

In all seriousness, depending on what happens tomorrow I might be interested in having a conversation with you about the merits of me engaging with you on a job to replace my consumer unit for either a split load, or RCBO's across all circuits, which would provide some opportunity for other tests? If nothing else it would increase the safety of what I have now so is still a worthwhile job... just seems to me it might be worth it if it's economic to get someone who actually knows what they're doing! (I'm making a wild assumption that you're in the trade professionally?).

Assuming you were interested of course, we could have a chat offline maybe?

 

[JohnW2]

Did neither of the electricians at least suggest some (more) bonding? I am remembering that on one test there was five volts between shower and waste yet none between radiator and waste.

Good question, but there might be an issue of 'what to bond to', and how. As I understand it, this 'waste' is just a metal surround/flange/whatever-one-calls-it connected to plastic waste plumbing. Even if it didn't sound like a pretty crazy thing to do, how would/could one bond to that?

Obviously the plastic waste cannot be bonded but there must be a good few ohms between the shower and the radiator pipe so, presumably, the shower is not sufficiently bonded.

This whole story is so confused/confusing. The pd between shower and radiator is not, in itself, relevant to a person standing in the shower and experiencing a tingle. However, maybe you are assuming/hoping/guessing that the radiator pipe has a good path to earth, implying that if there is a measurable pd between it and the shower, this must means that the shower pipework does not have a good path to earth, and therefore at risk of picking up stray/induced voltages - is that your thinking?

Gov: I'm not sure if we have ever asked ... is all the plumbing in your house copper, or is some of it plastic?

Kind Regards, John

 

[TheGovernor]

This whole story is so confused/confusing. The pd between shower and radiator is not, in itself, relevant to a person standing in the shower and experiencing a tingle. However, maybe you are assuming/hoping/guessing that the radiator pipe has a good path to earth, implying that if there is a measurable pd between it and the shower, this must means that the shower pipework does not have a good path to earth, and therefore at risk of picking up stray/induced voltages - is that your thinking?

Gov: I'm not sure if we have ever asked ... is all the plumbing in your house copper, or is some of it plastic?

Kind Regards, John

Just a reminder, the shower does not show any voltage between the shower main body and the radiator, sorry if I've not made that clear before.

Two electricians have confirmed that the earth bond between the pipes and the rest of the house is good (but in my case who knows, I'm losing faith that they're even testing the right things!!).

My pipework is pretty much exclusively copper, except for waste pipes of course, currently there are no plastic supply pipes anywhere I can see...

 

[TheGovernor]

Re your query on the worth of bonding the shower outlet drain :-

On the basis that the voltage tingling you is coming from the shower valve and/or hose, and you are standing in a pool of water that is intimate with the metal outlet collar, then bonding the collar to the shower valve will eliminate any potential between them and so stop the tingle.

BUT, that doesn't necessarily eliminate the original problem - it only alleviates the effect on your body.

Indeed, again, this is happening in other showers too, so would need doing on those too... plus as you say, there may (or may not) still be a problem laying undiscovered...

 

[JohnW2]

... On the basis that the voltage tingling you is coming from the shower valve and/or hose, and you are standing in a pool of water that is intimate with the metal outlet collar, then bonding the collar to the shower valve will eliminate any potential between them and so stop the tingle. ... BUT, that doesn't necessarily eliminate the original problem - it only alleviates the effect on your body.

I'm not sure that is necessarily the case. You are presumably assuming that the 'tingle' (only noticeable through broken skin) results from a resistive connection to earth through the waste collar/water/whatever. It's probably an extremely small current, and it therefore could be getting to earth via capacitive coupling from the OP's body. If that were the case, then bonding the collar of the waste (how on earth would one do that, if the waste plumbing was otherwise all plastic?) to the shower presumably could actually make things worse (tingle-wise), since the OP's feet as well as finger would then be connected to whatever potential existed at the shower, with the capacitive coupling from his whole body to earth still present, couldn't it?

Kind Regards, John

 

[EFLImpudence]

The pd between shower and radiator is not, in itself, relevant to a person standing in the shower and experiencing a tingle.

No, but it would be relevant to the problem but I made a mistake and there appears to be no pd between shower and radiator - that is as it should be