tingle from bare wires when off at mains

[foy9999]

A bit like the title says....

I rent an old barn and it has five 2-gang sockets inside. They have been quite neatly installed (about 30 years ago) with the cables running down the walls on wooden batons but bizarrely they were finished with exposed metal back-boxes floating in fresh air.

In the 16 years I've rented the place they have never caused my problems but a couple have never worked and I decided it was time to sort that and get rid of the (very rusty) metal back-boxes.

On the most rusted one I assumed it was the reason it wasn't working and spent the afternoon yesterday putting the plastic one on and it still doesn't work so am guessing the switch is corroded inside

Anyway that's enough preamble so to the reason for this post....

I switched the power off at the main switch and also popped the circuit-breakers (marked LTS & SKTS)

However when I was working (carefully) on the wires I was randomly getting a shock or a hot feeling. There was no going back so I had to proceed and usually there was nothing happening when I touched them but then I'd get a very annoying shock.

How can this happen when everything is off? Is there some sort of residual current in the wires? like you still get a drip from water-pipes even when the supply is off

decided to replace this exposed back box

with plastic one

main switch was off and both circuit-breakers were 'popped'

 

[Wildefalcon]

Yep, as a tenant I'd be handing that one back to the landlord. I'm all for DIY and not very keen on the over regulation of trades, but that's definitely not a tenant problem.

 

[foy9999]

Yep, as a tenant I'd be handing that one back to the landlord. I'm all for DIY and not very keen on the over regulation of trades, but that's definitely not a tenant problem.

You don't know my landlord lol

 

[bletchmonster]

If it's farm wiring, it's designed to only be used when wearing
wellies for insulation!! .
Probably a mix of cobwebs and damp bridging the isolator.

 

[foy9999]

If it's farm wiring, it's designed to only be used when wearing
wellies for insulation!! .
Probably a mix of cobwebs and damp bridging the isolator.

That's a thought

I had the cover off a while back and it was pretty dirty inside but am sure I gave it a dust out.

There is another main switch further back, at the farmhouse. Am thinking I should throw that one up too (big metal thing) but was concerned I'd turn the landlord's TV off at same time

dirt etc bridging isolator?

 

[dobbslc]

Death trap. There should be RCD protection on that, if you get tingles an RCD should have tripped so it's either missing or doesn't work. The water in that socket means it's ready for the bin and nothing else.
The fact you were getting shocks and still messed about with it tells me you really should get an electrician in asap.

 

[6ply]

30 or more years ago I used to work on farms. At that time, all the farmers I knew were happy to take shortcuts and do electrics on the cheap. I agree with the others in advising to get a qualified electrician in. Also, if the barn is damp or dusty those regular domestic sockets may not be the best choice.

 

[foy9999]

I won't be getting an electrician in.

Had that kind of advice on a similar post (https://www.mig-welding.co.uk/forum...n-box-with-2-switches-connected-to-it.117721/) and sorted it safely myself.

Just wanted to know if it was possible for wires to have 'current' lingering in them.

I think the domestic sockets will be better than the exposed metal back-boxes that are there just now

 

[Wildefalcon]

Assuming you aren't in a country with rules about such things..... Consider a new consumer unit, a decent earth rod, and new outdoor sockets throughout. Fitted by an experienced sparks. If this seems excessive, do you have any Landrover parts you could leave to me in your will?

 

[daedalusminos]

Can you actually trace the wires al the way back to the CU?

There won't be and voltage left in the wires, unless there's a connection elsewhere, someone may have 'borrowed' a wire for another circuit.

Also poor earthing can give tingle get a test lamp and check the wires.

 

[addjunkie]

If you were doing it safely, you would have proved dead before you started!

 

[knighty]

got a eter to test it?

it's probably something on one of the other circuts leaking back to earth a bit

gyessing the 2 circuts you left on are the lights? any chance they're damp? - thats probably where this is coming from.... used to have the same thing at work when I was a kid

 

[Pete.]

got a eter to test it?

it's probably something on one of the other circuts leaking back to earth a bit

gyessing the 2 circuts you left on are the lights? any chance they're damp? - thats probably where this is coming from.... used to have the same thing at work when I was a kid

Did they run electrics up the chimney back in the day then

 

[Dee J]

There's a brown black grey cable there that's doing something strange. Don't think it's the incomer, more likely the red black concentric is doing that. The brown is on the incoming unswitched live, but the black is on the switched neutral. It's possible that cable is feeding a load that back feeds the live to the switched neutral when that isolator is in the off position. Absolute danger to life electrocution hazard. The black and brown should either both be switched or both be unswitched. (never mind the obvious colour code issues, termination issues etc)

 

[Dee J]

And no. Mains wires don't have current lingering in them. If there's a tingle there's power coming from somewhere.

 

[Hopefuldave]

If it's an outbuilding then it's likely that the earth potential from the incoming supply (from the farmhouse) is different from local earth, should have a local earth rod - and there could be any kind of leakage locally from the state of that wiring!

Black is on switched Neutral... that's scary if it's true, switching the Neutral without switching the Live will leave the circuit with the full 240 on it, but apparently off as nothing works on it - there are reasons why it's forbidden in the Wiring Regs!

That brown-grey-black is the armoured cable improperly fixed and terminated at the top left of the box - have you followed it to see where it goes?

Dave H. (the other one)

 

[Onoff]

Just because you've switched that circuit off it could well be connected to another still live one.

Buy yourself a cheap multimeter from Screwfix etc and you can do some basic testing.

 

[Erie Fred]

That's a thought

I had the cover off a while back and it was pretty dirty inside but am sure I gave it a dust out.

There is another main switch further back, at the farmhouse. Am thinking I should throw that one up too (big metal thing) but was concerned I'd turn the landlord's TV off at same time

dirt etc bridging isolator?

I tore out a bunch of bad wiring at my parents place, but at least the main boxes were better than what you've posted here....Ugh.
"Y'all" do a bunch of stuff better than we do, but when it comes to electrical panels, I don't know.

I posted pix before, our wiring over here has larger panels for the same sized entrance that you have.
We've got the breakers clamped onto a buss bar, no wiring problems there, and plenty of room for the secondary wiring.
It's not like your having serious electrical problems all the time, houses burning down, etc. I just don't see why the differences from US to UK.

Here is the smallest sub panel, probably just what your barn needs.
I've wired a few of these before:

https://www.homedepot.com/b/Electrical-Power-Distribution-Electrical-Panels-Protective-Devices-Breaker-Boxes-Subpanels-Subpanel-Kits/8-Spaces/N-5yc1vZce9mZ1z1mou7/Ntk-elasticplus/Ntt-sub%2Bpanel?NCNI-5&sortby=bestmatch&sortorder=none

 

[mtt.tr]

Your landlord has a duty of care.

You despite having worked out your last lot of wiring you did a poor job, you also fought all advice.


This is a shower of **** only suitable answer is start again.

 

[MetalMonkey]

If the wiring has been that wet, it wants IR testing. The earthing arrangement also needs checking and testing - really you are going to need somebody with a MFT to come in and do those checks for you.

That board is shocking (apparently literally ), the SWA bodge needs sorting too.

As it stands that isn't offering anything much in the way of any user protection, and is clearly dangerous if you are getting shocks off it.
If I was working in a damp workshop I'd be wanting an RCD as a minimum for my protection - and I guarantee it would trip off if you tried to retrofit it to that.

You mentioned in the other thread you have a friend who is an electrician, in which case I'd be plying him with crates of beer and see if he can come in and help you sort it.
It would be possible to DIY (not legally obviously), but you would have to be serious about doing it properly and safely with some significant investment - trying to bodge it will be akin to polishing a potentially lethal turd.