Electrical socket is burnt!

Thread Starter

soopytwist

Joined Dec 23, 2016
42
I have a double 3-pin electrical socket and went to turn off the switch on the right but it wouldn't work, staying in the on position but the plastic rocker switch does move it just springs back to the on position. So I took it off the wall and found this horror show inside:
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Looking at it in more detail the reason the switch was stuck was because the metal contacts have welded together!!
YvKvhmE.jpg

I've now replaced the panel with a higher budget one, making sure it's wired correctly and tight with the two earth wires attached. I've also taken off some of the load on that one socket. Initially I had five things on the one socket: PC, two monitors, speakers and printer. I've now put the printer on the other socket on it's own, since I don't need the printer on all the while, and turned off the speakers until I need them. I'm using a Bestek 6-gang extension, surge protected and lightning protected; it's a very well made quality and expensive extension.

So what happened here?!

Mod edit: made images local - JohnInTX
 
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AlbertHall

Joined Jun 4, 2014
12,345
For some reason the contacts on the switch failed to make a good low resistance contact. When current flowed it generated heat which makes the situation worse as the contacts oxidise. So now there is more heat generated. Repeat until someone notices.
 

MisterBill2

Joined Jan 23, 2018
18,176
Those switch contacts have a certain current rating , and that rating also applies to the momentary inrush current. When that rating is exceeded then the contacts will fail. I do not understand why outlets in the UK need to have switches while here in the USA we do not. But certainly simple switches like the ones shown will be prone to failing.
 

rsjsouza

Joined Apr 21, 2014
383
@MisterBill2 you can get sockets without switches..but then you get arcing from the socket terminals over time...
I usually have some of these power strips with an ON/OFF switch to address these cases. Although they are not built into the wall, they tend to be a compromised solution.

Fortunately most the test equipment I have feature their own mechanical switch - however, more and more models are simply getting away without it (I am looking at you, Keysight E36312A! :mad:).
 

BR-549

Joined Sep 22, 2013
4,928
I was about to suggest throwing that garbage away and installing a real receptacle. It would have never occurred to me that such a electrical code could exist.

I suppose this is suppose to decrease standby power consumption? Has it caused any property damage or injuries yet?

Can one be arrested for installing non switched receptacles?
 

MisterBill2

Joined Jan 23, 2018
18,176
Buy MK sockets, not poundland ones!!


@MisterBill2 you can get sockets without switches..but then you get arcing from the socket terminals over time...
The means to avoid arcing at plugin and unplug is to have the device power switch off when plug-in and unplugging. Almost all of my electrical devices have a mains switch and I have them switched off when they are unplugged..
 

MaxHeadRoom

Joined Jul 18, 2013
28,619
When I was involved in the Electrical trade in the UK I was always surprised at the apparent current caused discoloration of the 13amp plug tops, compared to the seemingly wimpy N.A. plug, operating at twice the current on 120v, when I came here.
Dosn't seem to occur here.
Max.
 
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