Shocks from Bath tap

[SimpleSimon]

Hi Guys!!

Long time no speaky.

I've come across a problem that I need a little help with. My colleague was called out the other month to a house where they kept getting shocks off the bathroom taps. He called me up for some advice over the phone and we found out that the main bonding was only at 4mm not 10mm. It was however continuous as you can see its entire length.

He changed it to 10mm and he even cross bonded it on the taps. The fault we thought was coming from a faulty immersion heater so we changed this over, all was fine until the other week where they have complained again of getting electric shocks from the bath taps.
Im now going to go in there myself to see what can be the problem. My main thought now is there may be bonding but no/poor earthing. I think it's a TT system so would need to check if the rod is satisfactory.

Is there anything else I should be looking for when going in there?

Thanks

Simon

 

[Guest111]

Why did he change it to 10mm? if the earth was sound it would have done it's job on the original cable sounds like you have a problem and not just with the earth. If it were me I'd do a full IR test on each circuit.

 

[Engineer54]

Could be importing a fault from a neighbours installation via the water/gas service pipes.
All you can really do, is go through testing the whole installation eliminating as you go. Hope your taking an earth leakage clamp with you... lol!!

It could be a long or short day for you, let us know what you find!!

 

[Paul.M]

Simon welcome back mate, long time no see

Another thing it could be is static, is the floor carpeted?

 

[Marvo]

My record for one of these type of faults was seven visits with over 30 hours on site in total and it was a favour job for a friend of the family. Turned out to be the shower drain that was actually at an elevated potential but only when water was flowing through it. Eventually tracked it down to a combination of tree root in the drain and leaking garden light IP66 connection box in close proximity. Never again!

 

[Darkwood]

If the fault/leakage is intermitent then you may be in for a difficult ride... as already suggested the fault could be external to installation and piggy backing on the house bonding, if this is the case it will not operate any earth leakage devices or mcb's, if you are on site and you find this fault active while there then isolate power to the premises and see if the current is still flowing down the earth... if so a fault external is highly likely from DNO issue to neighbours fault tracking or even something as sinister as a street light.
I had DNO dig a full street up replacing all their corroded old wooden joints boxes on the old cable which had caused its earthing to be lost on a TNS ... a neighbours high impedence fault on his microwave made all the radiators live in a house we just rewired and believe you me was a bugger to work out the issue!

 

[SimpleSimon]

Why did he change it to 10mm? if the earth was sound it would have done it's job on the original cable sounds like you have a problem and not just with the earth. If it were me I'd do a full IR test on each circuit.

I got him to change it as I don't know how old it was or the impedance on it. I agree I would have thought the earth would have done its job of carrying a fault current to trip the breaker.

But now yes it could be piggy backing off anything!!!! What makes it worse is that these are gypsy sites which we are working with, just a brick out house. And Now I think even further the plot next door has also complained of shocks. Hmm, the only common thing external to these two plots that could pass a potential is the street lighting outside. Good idea to look at that?

 

[Guest111]

You have to watch gypsy sites, I went to one for a breaker that kept tripping they had a 16a combined unit rcd/mcb/16a blue socket and had a splitter off this feeding 2 vans and 2 sheds and some of the earths weren't connected.one other thought keep your eyes open for wires going into sheds,they may be growing "pot" plants.

 

[singingfraggle]

had a similar problem on a pme system broken neutral incomer everything to earth
make sure it is tt

 

[Thefailsafe2012]

My record for one of these type of faults was seven visits with over 30 hours on site in total and it was a favour job for a friend of the family. Turned out to be the shower drain that was actually at an elevated potential but only when water was flowing through it. Eventually tracked it down to a combination of tree root in the drain and leaking garden light IP66 connection box in close proximity. Never again!

Gawd almighty! Hope I don't ever have to deal with that!

 

[Rampantchilli]

could be as simple as the screw holding the bog down going thru the service cable, had that too, caused shocks at the kitchen sink!!!

 

[shagbite]

I got him to change it as I don't know how old it was or the impedance on it. I agree I would have thought the earth would have done its job of carrying a fault current to trip the breaker.

But now yes it could be piggy backing off anything!!!! What makes it worse is that these are gypsy sites which we are working with, just a brick out house. And Now I think even further the plot next door has also complained of shocks. Hmm, the only common thing external to these two plots that could pass a potential is the

street lighting outside. Good idea to look at that?

that's where i'd start. you might find that someone's rigged up a 'temporary supply' from one of the lamp posts.

 

[SimpleSimon]

Ok so I visited the site today.
Plot 5&6 are connected together, I don't think the pipes workis though, they seem to be separate. Plot 5 has only just started getting shocks from the sink this last week, plot 6 going on a month now.
Prior to this the kitchen sideboard and sink have recently been upgraded and apparently the shocks have started since than. There is no screws or the sorts anywhere near the electrics as these are all run in conduit above the Worktop. But they may have cut the original bonding away( now being reinstated).

I've left the property witha theory. Plot 6 has power to an outside shed and flood lights. I've taken the power out of these and told them to keep it off. As these are the most suspect outdoor fittings. They've also commented saying the shocks have got worse recently which I'm putting down to the wet weather we are having recently and extra water getting inside a hidden light or junction box.

 

[telectrix]

if you're missing earthihg and bonding. you'll find it on the back of a transit pick-up.