Electric shock from double socket

[Foss13]

This seems a bit of a strange one to me - but here goes….
My wife told me this morning that when I was out last night she got an electric shock from her iron and the RCBO tripped. It turned out that the shock was from the (metal) double socket when she switched the socket off. Today I’ve plugged the iron in to the same socket and can’t replicate this and the iron is still working.
Any ideas what is likely to have happened? Circuitwise everything is fairly new - five year old kitchen extension all new electrics certified etc. with no problems during that five year period, so I’m assuming wiring is going to be OK. Can socket switches breakdown to give a (transient) fault like this and would there be a very brief period in which a shock could be experienced before the current goes to earth and/or trips the RCBO? Clearly what she experienced wasn’t too dramatic.
I’ll take the faceplate off to try to find the make and order a matching new one - anything I should look for to give clues as to what happened?

 

[johnny2007]

Loose wires?
Unearthed metal plate or backbox?

 

[JohnD]

Electric irons are subject to repeated bending of the flex where it enters the handle, this often causes RCD trips and worse when the insulation cracks. You would not replicate such a thing unless you happened to be holding the iron in the same position and moving it in the same way. Sometimes spilt water from filling a steam iron will contribute.

There may also be something wrong with the socket wiring. You should not be able to get a shock from an earthed socket unless you were standing on or touching something that was live. A wire might have come loose or been pinched by a screw.

The actual socket itself is less likely to be at fault.

You can buy a socket tester, a simple plug in device that can detect some gross wiring faults. Usually around £10 to £20.

 

[ebee]

This part of your story really worries me "Today I’ve plugged the iron in to the same socket and can’t replicate this and the iron is still working." That is you can`t replicate this. Depending upon what you actually did to replicate this then it could well be extremely dangerous.

I advise you to seek expert help - Although Electric Shock does not always become Electrocution it often can be so.

 

[bernardgreen]

For a significant shock there has to be two points of contact with the person. (*) When your wife switched off the socket and got a shock what else was she touching at the time. Either that object or the socket could be Live due to a fault.

As Ebee said, get an electrician to look at the matter,

(*) a short sharp "shock" can be felt when static electricity that has built up on a person discharges to Ground via any metal item the person touches

 

[Foss13]

This part of your story really worries me "Today I’ve plugged the iron in to the same socket and can’t replicate this and the iron is still working." That is you can`t replicate this. Depending upon what you actually did to replicate this then it could well be extremely dangerous.

I advise you to seek expert help - Although Electric Shock does not always become Electrocution it often can be so.

That’s not an unreasonable comment - but don’t forget that the RCBO tripped the kitchen sockets circuit. My assumption was that the iron was dead by that point - and plugging it in again would just confirm that, requiring a new one to be ordered. I would think 90% of the public would do the same thing (Maybe even electricians?).
Only afterwards did my wife say that the socket itself seemed to give her the shock just before the RCBO tripped.
I’m quite capable of switching off the power and having a look for some obvious loose wiring in the socket - just didn’t have the opportunity today and as all the sockets are currently working (as they have since the extension was completed), it seems a bit of a long shot to be honest.
Any expert help would probably be the electrician who did the install five years ago.

 

[Jon c]

While a fault with the actual socket is unlikely they do occur so don't discount the possibility, I had one a while ago that internally shorted L&N when switching it off. If your socket had an internal fault that shorted L to E when switched, it is possible the user would feel a shock before the RCBO disconnected.

 

[Foss13]

For a significant shock there has to be two points of contact with the person. (*) When your wife switched off the socket and got a shock what else was she touching at the time. Either that object or the socket could be Live due to a fault.

As Ebee said, get an electrician to look at the matter,

(*) a short sharp "shock" can be felt when static electricity that has built up on a person discharges to Ground via any metal item the person touches

I did think about static - but that wouldn’t trip the RCBO Would it? I could contact the electrician who installed the sockets along with all the other wiring (five years ago) but as replacing the socket is a simple job that I have done before, I might just do that anyway.

 

[Foss13]

While a fault with the actual socket is unlikely they do occur so don't discount the possibility, I had one a while ago that internally shorted L&N when switching it off. If your socket had an internal fault that shorted L to E when switched, it is possible the user would feel a shock before the RCBO disconnected.

Thanks - that sounds like the most likely possibility here, as all the others seem to require many things being wrong at the same time. As mentioned it was a professional install that has had no problems for five years, so basic wiring faults seemed a bit unlikely.