Faulty Plug Socket

[Hopkirk]

Advice please.

At my Mum's house I had to unplug the dishwasher and pull it out.out.

When I plugged it back in to the socket, which had the switch in the off position, the circuit breaker for the sockets flicked off.

When I tried it again, the same thing happened.

Can anyone knowledgable suggest what is wrong?

I plan to replace the socket, but does this suggest it is wrongly wired?
Surely with the switch off there should be no surge to trip the CB?

[bhg481]

It could be that the socket has been wired incorrectly ie, live and neutral reversed. Another possibility is that the switch has become stuck in the "on" position.
Your own suggestion of replacing the socket is a good one.

[Buenchico]

Probably just a duff switch or some other reason why the circuit is shorting inside the socket (such as water ingress).

It's fairly common. I had a similar problem with a kitchen worktop socket just a few weeks ago. (I suspect that many years of being close to a steaming kettle hadn't helped!). £1.14 for a new double socket from Screwfix was all that was needed to fix the problem.

[Old_Geezer]

Things develop errors. Switch seems to not work and plugging something in seems to short something. Not worth pondering. Replace & forget.

[Hopkirk]

Thanks all.

I already have the new socket, but worry that if I copy the connections and it is incorrectly wired, I will duplicate the error.

I have an electrical test screwdriver, so I will very carefully investigate which places are live.

[SlackAlice]

This might help

http://www.diy.com/departments/bq-230v-socket-tester/178677_BQ.prd

[The Builder]

Hoppers, are you sure it's the MCB that is operating and not the RCD trip?

[-Talbot-]

I would turn off power, whip of the socket and take a look. It may be a short circuit that has just been waiting to happen through loose wiring.

[Hopkirk]

Builder, it seems to be a main circuit breaker covering all the sockets in the house, not an individual one for one circuit.

[Old_Geezer]

The connections on the back of the new socket are marked. You should have two cables going to it. Stripey wires go to the connection marked earth. Bizarrely the mud coloured ones connect to live. Blues to neutral.

[Old_Geezer]

That sounds like an RCD implying an earth issue.

[Hopkirk]

Thanks SlackAlice, that looks like a good idea, I will get one.

I have taken the socket off and peeped behind. There are no obvious loose or stray wires.

[Hopkirk]

Black and red, Old Geezer

[Togo]

Red live . Black neutral.

[EDDIE51]

Can you plug the dishwasher into a different socket and see if it still trips.

[Togo]

You may have a stressed lead to the d/washer Hopkirk. Inspect all the lead for cracks or kinks particularly where it goes into the plug and the machine. When you rewire a new plug cut off a few inches of the lead.

[-Talbot-]

Plug another appliance (iron) in the socket the dishwasher uses and see if it trips

[Hopkirk]

I won't be there for a couple of weeks, but will investigate further then.

It makes no difference, but I meant to type tumble dryer, not dishwasher.

I have been on ebay and ordered one of SlackAlice's socket testers, so might get more info on the status of the socket then.

[BRIGHT SPARK]

Hoppy......you have a Neutral to earth fault within the flex or appliance.The socket feeding the appliance is a single pole switching type meaning ...the Neutral is still connected even when the switch is off.

[Togo]

Hi sparks, I did not want to make a definitive statement but was hoping you would show. I am with you all day on that (that is why I said check the supply lead). Hope you are good.