Wall Socket both earth and live have power?

joe2010

Hi,
Friend of mine was in our new house (built around 1980).

He put 2 phase testers in a wall socket - one in top part of the wall socket and one in right part and they both lit up.

He did the same with another socket on different wall and it only the right part lit up
- which he said is correct only the right part (live) should have current.

Is he correct and is this dangerous and something that must be fixed urgently?

Thanks.

2011

"Phase testers" such as the one in the photo below are notoriously unreliable. Treat anything that a device such as this provides accordingly.
A professional will only trust proper test instruments.

eeguy

2011 wrote: »

"Phase testers" such as the one in the photo below are notoriously unreliable. Treat anything that a device such as this provides accordingly.
A professional will only trust proper test instruments.

Phase testers are crap. Get the multimeter out!

Though in fairness, if mains earth was hooked to live, you'd definitely know.

joe2010

thanks you both, I will get a proper instrument like a multimeter

Joe1919

I would take a guess that the earth is broken or not connected in the affected socket (or possibly other sockets in the same circuit), and the phase tester is lighting up due to 'induced' or 'stray capacitance' between the unconnected earth and the live.
The fault could be a broken or unconnected earth wire at the back of another socket that's feeding the affected socket.

PS If the house was built in 1980, there may be no earth leakage (RCB) protection so its possible that you may have a combination of unearthed sockets and no RCB(earth leakage) protection, and this would be potentially very dangerous and should be rectified as soon as possible.

AMKC

1980 ain,t that old its old but it should have been rewired by now. My parents old house was built in the 70s and has an MCB board. if your house does not have one of these and still has fuses get it changed. The RCD in an MCB board offers far more protection to a person than a fuse ever will as they are just designed to protect the cable from going on fire.

I agree with what Joe1919 above said. The earth cable also could have broke.

There is socket testers you can buy that you plug into the socket and it tells you if it is wired right. They are relatively cheap. It might be no harm getting an electrician in to check over the house and even get a quote if you do need a new board and some rewiring done.

joe2010

I'll definitely get an electrician to give the place the once over. Thanks all for your advice.

Bruthal

Well, it seems to be that the OP states that 2 phase testers where used at the same time, one into the phase (live) pin of a socket, and the second one into the earth pin.

Was it a case of both phase testers used at the same time, one in each hand?

In such a scenario, I would expect both phase testers to light brightly at a good properly earthed socket.

And, one to light brighter than the other at a socket with no earth connection.

Bruthal

Joe1919 wrote: »

and the phase tester is lighting up due to 'induced' or 'stray capacitance' between the unconnected earth and the live.

If the OPs friend had a phase tester in each hand at the same time, one in earth, other in live, both will light brightly.

Bruthal

joe2010 wrote: »

Hi,
Friend of mine was in our new house (built around 1980).

He put 2 phase testers in a wall socket - one in top part of the wall s exocket and one in right part and they both lit up.

He did the same with another socket on different wall and it only the right part lit up
- which he said is correct only the right part (live) should have current.

Is he correct and is this dangerous and something that must be fixed urgently?

Thanks.

As said by others, phase testers are not the greatest test devices.

But if he was using 2 at the same time, one in each hand live to earth, both will light at a healthy socket.

At the other socket where only one lit, either the one to the earth pin was not making contact, or the earth is not connected.

This all assumes he had a phase tester in each hand at the same time, which seems a strange test method.

Dardania

Have to get the L/N shutter down somehow, so explains why 2 were in use simultaneously.

Bruthal

Dardania wrote: »

Have to get the L/N shutter down somehow, so explains why 2 were in use simultaneously.

It's just that 2 in series like that (with the person) made the person using them believe the earth on the socket was live. If they did in fact use both together.

2011

Devices such as this lighting provides no conclusive data.

I remember a senior electrical engineer telling me the following story:

He was on site in a large manufacturing plant when a company director called him over. The director touched a phase tester off a random bonding cable on a piece of equipment and it lit.
"Look at this!" He shouted, "I am loosing electricity everywhere. This is costing me a fortune!! I need you to fix this immediately!".

Bruthal

2011 wrote: »

Devices such as this lighting provides no conclusive data.

Not saying it does.

I remember a senior electrical engineer telling me the following story:

Don't think I ever seen a neon one light which had equal potential on both ends.

2011

Bruthal wrote: »

Not saying it does.

I know.

Don't think I ever seen a neon one light which had equal potential on both ends.

The potential is not necessarily exactly equal.