Electric shock from sink

[AllieG]

I was in my kitchen this afternoon and kept getting an electric shock off the sink. I unplugged the washing machine and dishwasher and microwave but it still happened. I was even getting electric shocks off the water coming from the tap. I wasn't touching the tap just putting my hand under the water to check it was hot. Nothing has changed in my kitchen and I didn't get an electric shock off anything else in my house or kitchen just the metal sink, I didn't even get it from touching the pipes under the sink. The only thing I can link it to is a cable company digging up the pavement on the opposite side of the road since it only starting happening while they were working today. It was fine before lunchtime but started this afternoon. It is still doing it now though so could they have done something to the electric supply. I only ask because it isn't nice to touch my sink and get an electric shock off it.

 

[dontbelieveawordofit]

a good start would be...... stop touching it , preferably before it kills you.

 

[ericmark]

If all is OK in the house, then even if some thing was done in the road, you should not get a shock, the idea is we bond gas and water pipes to the electric earth, so even if the water is at 230 volt to real earth you will not get a shock in the same way as when birds sit on power lines.

There may well be two faults, and work in the road could have well broken the combined earth/neutral of the supply cable, which is very dangerous so call the power company straight away and turn off power at main incomer, they will get there fast. But also your house needs testing as well, as it may well burn out anything you switch on, but it should not have given you a shock.

 

[JohnW2]

I was in my kitchen this afternoon and kept getting an electric shock off the sink. I unplugged the washing machine and dishwasher and microwave but it still happened.

It might sound like a silly question, but can you describe what these electric shocks were like?

Kind Regards, John

 

[ericmark]

If my guess is right, unlikely to get an answer, likely very little still working in that house.

 

[ianmcd]

you should not get a shock, the idea is we bond gas and water pipes to the electric earth,

Not any more, most gas and water mains are PE now

 

[bernardgreen]

As John asked, what were the shocks like ?

Was it a short sharp shock, ?

If it was then maybe it was a static electric shock caused by discharging static electricity built up on your body ( harmless ) via the sink. The voltage of a static charge can be high enough to create an arc several millimetres long. It would not be necessary to touch the sink for this discharge to happen. It would discharge through a finger to the sink.

A static charge on a human body can be high voltage but very little static electrical energy can be stored and thus current only flows for a few micro seconds before the charge has been dis-charged.

A severe shock requires two points of contact with the body and a voltage difference between those two points of contact. The sink appears to be one of them, was there another one that you were touching when you touched the sink. A damp floor or work surface can be the other point of contact if there is live equipment in contact with the damp area.


As advised you should get a competent electrician to check sink is not Live and verify that the wiring is safe..

 

[Nige F]

Anything is possible with cable co.s and electricity " boards " I have witnessed half a street turned off for 24 hours because they hadn't got the right kit to lift a new transformer into position - old one disconnected and left. Another time half a mobile home park was struck with appliances blowing up - they were fitting a new transformer and got the phases wrong , only noticed after the maintenance guy ran out and told them the 3 phase motors were running in reverse in the utility yard. There were vans running new appliances in daily after that.

 

[crystal ball]

Seen this before on PME when neutral failed on overhead pole

 

[JohnW2]

Seen this before on PME when neutral failed on overhead pole

As bernard has implied, even that should not result in a shock hazard if the building is properly constituted as an equipotential zone - was main bonding absent or inadequate in the case you saw?

Kind Regards, John

 

[crystal ball]

Long time ago, my mate wired the property and he was a a stickler for bonding so I would say yes, the sink, Aga etc were live

 

[JohnW2]

Long time ago, my mate wired the property and he was a a stickler for bonding so I would say yes, the sink, Aga etc were live

If main bonding (and all required earthing) were in place, such that 'everything' in the house was 'live', then, as has been said, there would be no shock hazard. Of course, there might have been some 'unbonded' things, like a solid floor in continuity with earth, but even that would probably not be an issue for anyone wearing shoes (or probably even just socks!).

Kind Regards, John

 

[AllieG]

In answer to the questions about the shock. It was just a sharp shock. I think I worked out what the problem was. I had a microwave near the sink but it was unplugged and turned off. I plugged it in to heat up some milk for hot chocolate and when I pressed the button it felt as though the microwave was full of static. I immediately unplugged it and put it in the hall to take to the tip tomorrow. I then went back to wash the pan and my arm touched the sink and I got another shock. I didn't think that if something had been unplugged for 24 hours it could still cause shocks like that and not if it wasn't anywhere near my sink. I did speak to an electrician this morning who said it was probably just static but if it carries on to ring them and they would come out. I am going to leave it a day or so and see what happens as I think the microwave was the problem and if it doesn't help I will ring the electrician and see what they say.

 

[winston1]

Why did you think the microwave was the problem? Seems pointless taking it to the tip if there is nothing wrong with it. It could be your earth is not earthed and has leakage on it. You would feel this if you touched the microwave or the sink. Personally I think it is just static though and a new microwave will not fix that.

 

[FrodoOne]

As John asked, what were the shocks like ?

Was it a short sharp shock, ?

If it was then maybe it was a static electric shock caused by discharging static electricity built up on your body ( harmless ) via the sink. The voltage of a static charge can be high enough to create an arc several millimetres long. It would not be necessary to touch the sink for this discharge to happen. It would discharge through a finger to the sink.

A static charge on a human body can be high voltage but very little static electrical energy can be stored and thus current only flows for a few micro seconds before the charge has been dis-charged.

A severe shock requires two points of contact with the body and a voltage difference between those two points of contact. The sink appears to be one of them, was there another one that you were touching when you touched the sink. A damp floor or work surface can be the other point of contact if there is live equipment in contact with the damp area.

Bernard put the situation very well, I thought.

In answer to the questions about the shock. It was just a sharp shock.

While you may not wish to do so, I suggest that next time you feel any “short sharp shock” when you touch one metal object, stand still, do not make any unnecessary movement and “touch” the same metal object again.

If you again receive a similar shock, it is not static electricity. (There is probably a fault, which needs to be investigated and corrected by a competent person.)

If you do not receive a shock the second (third, forth …..) time, it is (just) static electricity.

If the weather (or the house) is warm and dry where you are and you are wearing clothing made of synthetic material, it is likely that you are generating a "charge" as you move about - and it does not take much movement.

Many years ago, I encountered a situation when working in a newly refurbished office building where I received a "shock" each time I walked across the carpeted floor and touched the "lift button". The capet was made of synthetic fiber and the soles of my shoes were also a synthetic material.
To obviate the problem i developed the habit of touching the button using a coin, key or other metal object.
The discharge still took place and, under the right conditions, it could be seen or heard. However, I then did not feel it, because it took place at the edge of the metal object(s).