What on earth was causing this?

[HappyHippyDad]

Today I had a routine socket change. The present one was tripping the RCD. The customer had used one of those double conversion sockets that utilise a single back box. I noticed that the right hand switch on the socket would not turn off.

I chased out and fitted a proper double socket. All tests were fine and the switch worked as it should. I then plugged the customers plugs back in switched them back on and thought I'd switch them off again just in case they still tripped the RCD for some bizarre reason. But, the right hand switch would not switch off.

I then changed the socket again as my new socket now had a faulty switch on it. The new switch was fine, until I plugged the customers socket back in and switched it on. As soon as the socket was energised by this particular plug the switch would become faulty and not allow itself to be switched off (just on the side that had this particular plug in it), even when the plug was removed.

I then got one of the sockets I had previously used and loosened the screws holding the socket together. The switch started working again (i.e allowing itself to be switched off), I tightened the screws back up and it was fine. However, the same thing happened everytime I plugged this particular plug in. I then chopped off the plug (it was an extension lead with 8 sockets on it and 2 USB slots), fitted a new one and everything worked fine.

Why would a plug do this this???

 

[Midwest]

You lost me after double conversion.

 

[Baker1988]

Was the plug a proper one that comformed to the regs as it could be that the plug had too long live pins and actually knocked something inside that would not normally be knocked.

 

[Wilko]

Proper X Files material by the sounds ...

 

[HappyHippyDad]

This is the plug that was doing it. It has the correct BS number and all pins are normal size as I have compared them next to another plug.

I do get a bit long winded Midwest.. sorry!

Basically, when the plug was plugged into a socket and switched on, the socket would then not switch off, even when the plug was removed.

Thats all I needed to say really, isn't it

 

[Wilko]

Out of interest have you tried it in a new outlet, one not mounted onto the backbox? How about in another outlet in the house?

 

[Toneyz]

Could be an L-N short did on what you have plugged in. Did any protective devices blow or trip?

 

[johnduffell]

Did you check the pins size and spacing with a vernier or similar, also are they twisted in any way?
Very intriguing problem!

 

[Pete999]

You lost me after double conversion.

Me as well

 

[marconi]

What are the make and model number of the socket?

 

[SparkyChick]

What's connected to the extension lead?

I had a socket at my parents place which supplied my computer gear. It sometimes ended up stuck in the on position which I believe was due to the inrush current causing the contacts to stick together. This happened numerous times before it eventually welded itself permanently in the on position.

 

[telectrix]

my money's on the plug being a dodgy import. them Chinese can mould any numbers and letters on it. don't mean it complies with any standards.

 

[Midwest]

Time for a Vernier Caliper then

 

[gazdkw82]

Anything fusing the contacts in the switch?

 

[ruston]

Sounds like the 13amp welder syndrome , until it wont come out at all.
Sadly a lot of stuff is rubish now.