Check your electrical sockets and adapters

[Fox Morgan]

I recently had two close shaves with possible electrical fires.

I thought I'd share it because I'm usually very careful and it still took me by surprise.

Back in December I had a two way adapter fail, with the plastic melting around the live pin and causing the smell of very hot plastic to make me have a look at it. It wasn't visible from the outside.
I was running a 3kw kickspace heater and some fairy lights.

I removed the adapter. Fairy lights off.

Two weeks later, burning smell again. The fan heater was plugged into an extension lead. This extension has a european plug on the end because my boat only has european plugs. It was going into a UK adapter then into a regular British 3 pin socket. (the reason for this is a whole other story) Again, just the 3kw kickspace heater, nothing else.

I'd used this adapter for a few years, I'd also used the extension cable and european set for years too. Never had any problem.

This is probably where the problem stems from, the years of happy useage. The fuse in the adapter didn't blow, because it wasn't overloaded, it was most likely dirty or weakened connections internally that caused the excessive heat.

(Some professional electrician will no doubt correct me on here and tell me otherwise.)

I wrote a blog post about it with images, if anyone wants to see what happened and what overheated sockets or adapters look like (please ignore the mild swearing if you do happen to have a look).

I've since swapped out the 3kw heater to something less power hungry.

http://www.boogie-nights.org/2018/01/electric-friends.html#more

 

[penberth3]

Not entirely clear, but have you really been running 3kW through a cheap adapter block?

 

[Richard10002]

12Amps is quite high for a 240V circuit. Not too high, merely quite high.

 

[Fox Morgan]

Not entirely clear, but have you really been running 3kW through a cheap adapter block?

erm... yes. it was rated at 13amps... I was running just less than that

 

[penberth3]

erm... yes. it was rated at 13amps... I was running just less than that

I think the penny has dropped. It might say 13A on your 69p adaptor but these things really aren't designed for that.

 

[Fox Morgan]

I think the penny has dropped. It might say 13A on your 69p adaptor but these things really aren't designed for that.

it was more than just the adapter. that was just one of several things that decided to overheat, despite them being used for several years without problem. The adapter was the red herring. I initially thought the same, more fool me for using a cheapish adapter to put fairy lights on, but even when it was taken away and back to standard set up, the standard set up also decided to overheat two weeks later.

 

[neilf39]

Had similar with a 2kw heater. It was corrosion on the wires in the plug making a high resistance area which got very hot under high current. I now check my plugs and sockets regularly. I guess it's one reason moulded on plugs came in.

 

[Giblets]

Not unknown for the terminal screws in the various fittings to loosen over time. This even happens on with hard wired switches and sockets on land so on a boat with more handling and movement particularly extension cables the problem is more of an issue.

Great excuse to buy one of those Flir Thermal Image camera thingys for the smartphone!

 

[biscuit]

Slight thread drift: my European built boat has 2 mains outlets, 2 pin continental style. I have never got around to fitting the UK style "square" pin sockets, but use a travel adapter instead, so far without a problem.
I have only recently noticed that the adapter has "not for use in the UK, use only on the continent" embossed on it!
I am not sure why, or what potential harm can ensue: could someone enlighten me?
I think it's probably time I put UK sockets on, anyway.

 

[JumbleDuck]

I have only recently noticed that the adapter has "not for use in the UK, use only on the continent" embossed on it!
I am not sure why, or what potential harm can ensue: could someone enlighten me?

I don't think it's risk of harm. It's just that everything in the UK is supposed to be 13A, not Schuko + adaptor.

 

[LadyInBed]

Over time, the grip on the adapter connections weakens (gap to take plug pin widened) so you get a poor and resistive connection which generates heat which leads to fire!

 

[lw395]

Slight thread drift: my European built boat has 2 mains outlets, 2 pin continental style. I have never got around to fitting the UK style "square" pin sockets, but use a travel adapter instead, so far without a problem.
I have only recently noticed that the adapter has "not for use in the UK, use only on the continent" embossed on it!
I am not sure why, or what potential harm can ensue: could someone enlighten me?
I think it's probably time I put UK sockets on, anyway.

In the UK you might use it to run the wrong thing from a shaver point or similar?

 

[lpdsn]

In the UK you might use it to run the wrong thing from a shaver point or similar?

When working in Poland one of the Poles showed me what they do when they travel to the UK. Basically, ram something into the Earth of the socket to open it then force the Polish (Continental) plug into to the live & neutral. Could be worse, they could be doing it with bare wires.

An adaptor is a bit of an improvement.

 

[paulajayne]

Adaptors are asking for problems as failure rate is very high.
Far too easy to overload, if you must use them then buy the type with a fuse fitted and then downgrade the fuse from the standard 13 amp one to 10 or even 5 amp.

Extension leads again have a high failure rate, coiled up with a high load on them the cable will overheat, melt and short out.

If you need extra sockets then get them fitted and ensure that the breaker is of the right size.

 

[JumbleDuck]

When working in Poland one of the Poles showed me what they do when they travel to the UK. Basically, ram something into the Earth of the socket to open it then force the Polish (Continental) plug into to the live & neutral. Could be worse, they could be doing it with bare wires.

I've done that. It works quite nicely, but the continental plug really needs to be the plastic type with a metal tip, as they spread the slight amount necessary more easily than the all-metal ones.

Years ago I was working in a university physics department where one of the research groups had an old mains radio in their lab. It had lost its casing years before, so the life chassis was exposed to anyone who cared to touch it. Nobody did because, hey, physics. One day the H&S rep spotted it and without saying a work took out a pair of wire cutters, removed the plug and walked off. Had he returned the next day he would have found the radio still in use, powered by the two stripped ends of the cable wedged into a 13A socket ...

 

[lpdsn]

Slight thread drift: my European built boat has 2 mains outlets, 2 pin continental style. I have never got around to fitting the UK style "square" pin sockets, but use a travel adapter instead, so far without a problem.

You could fit the right plug to your gear to fit the sockets. Beware there isn't a universal Continental standard though. Live and Neutral are interchangeable, hence adaptors work, but the Earth arrangements vary. I have two French plugs that I bought on a visit to France in the spares bin - they won't fit the German sockets on my boat.

 

[lpdsn]

I've done that. It works quite nicely, but the continental plug really needs to be the plastic type with a metal tip, as they spread the slight amount necessary more easily than the all-metal ones.

Years ago I was working in a university physics department where one of the research groups had an old mains radio in their lab. It had lost its casing years before, so the life chassis was exposed to anyone who cared to touch it. Nobody did because, hey, physics. One day the H&S rep spotted it and without saying a work took out a pair of wire cutters, removed the plug and walked off. Had he returned the next day he would have found the radio still in use, powered by the two stripped ends of the cable wedged into a 13A socket ...

One place I worked they wanted to charge us for every cup of hot water to make tea, so one of the technicians brough in a heating element from something or other and we wired it up and used to stick it in each cup of water. We called it Old Faithful coz when the water boiled it shot about 6" up in the air. We then remove the element and stuck a tea bag into what was left of the boiling water in the cup.

It only went on for a week before they relented and gave us free hot water again.

 

[Lon nan Gruagach]

I recently had two close shaves with possible electrical fires.

I thought I'd share it because I'm usually very careful and it still took me by surprise.

Back in December I had a two way adapter fail, with the plastic melting around the live pin and causing the smell of very hot plastic to make me have a look at it. It wasn't visible from the outside.
I was running a 3kw kickspace heater and some fairy lights.

I removed the adapter. Fairy lights off.

Two weeks later, burning smell again. The fan heater was plugged into an extension lead. This extension has a european plug on the end because my boat only has european plugs. It was going into a UK adapter then into a regular British 3 pin socket. (the reason for this is a whole other story) Again, just the 3kw kickspace heater, nothing else.

I'd used this adapter for a few years, I'd also used the extension cable and european set for years too. Never had any problem.

This is probably where the problem stems from, the years of happy useage. The fuse in the adapter didn't blow, because it wasn't overloaded, it was most likely dirty or weakened connections internally that caused the excessive heat.

(Some professional electrician will no doubt correct me on here and tell me otherwise.)

I wrote a blog post about it with images, if anyone wants to see what happened and what overheated sockets or adapters look like (please ignore the mild swearing if you do happen to have a look).

I've since swapped out the 3kw heater to something less power hungry.

http://www.boogie-nights.org/2018/01/electric-friends.html#more

Your biggest mistake was to blame the adapter. More likely to cause overheating of a pin is poor contact from the socket.

 

[Fox Morgan]

Your biggest mistake was to blame the adapter. More likely to cause overheating of a pin is poor contact from the socket.

oh my biggest mistake recently was going on a really really bad date, but yeah the second biggest was blaming an adapter for a problem elsewhere.

 

[lw395]

I've done that. It works quite nicely, but the continental plug really needs to be the plastic type with a metal tip, as they spread the slight amount necessary more easily than the all-metal ones.

Years ago I was working in a university physics department where one of the research groups had an old mains radio in their lab. It had lost its casing years before, so the life chassis was exposed to anyone who cared to touch it. Nobody did because, hey, physics. One day the H&S rep spotted it and without saying a work took out a pair of wire cutters, removed the plug and walked off. Had he returned the next day he would have found the radio still in use, powered by the two stripped ends of the cable wedged into a 13A socket ...

That's terrible.
Proper procedure is to find a mains lead with a PAT sticker on, cut and strip and twist the wires onto what you want to power.