Melting plug sockets

salad17 · 14-03-2020 4:14am #1

Hi,

We have a washer and dryer running from an extension cord with surge protection etc.

Sometimes they trip the switch and we reset it, figuring it draws too much power at a certain part of the washing cycle (since the drying cycle doesn’t vary)

Then we smelled burning and realized the plug had melted in the wall outlet. After some googling it seemed the wall outlet was likely the problem. I don’t know why the fuse in the plug wouldn’t have blown before the whole thing melted, the outlet was melted too though.

New extension lead in a different wall socket running only the dryer on its own (dryer is 3 months old) and a few weeks later, it’s melting again!!

Is it the dryer? Why isn’t the fuse in the plug going? Or the trip switch? And why can’t they handle a single appliance?

Thanks for your help!

endacl · 14-03-2020 4:16am

Unplug it immediately. Phone an electrician on Monday.

salad17 · 14-03-2020 4:17am

Photos

salad17 · 14-03-2020 2:14pm

endacl wrote: »

Unplug it immediately. Phone an electrician on Monday.

Yes we have unplugged it!

Just wondering what the problem is likely to be, the applicable, extension chords, wall outlet, or something else?

Thanks

Doolittle51 · 14-03-2020 2:35pm

That plug looks very old. A couple of things could have caused the issue. The cable size could be too small for the fuse. Could have been a loose screw causing arching. Insulation could have been in bad condition.
Either way, you should try to plug the dryer directly into the socket without the need for an extension lead. Also, it's not a good idea to have the dryer and the washing machine on at the same time, plugged into the same socket.

Obviously the socket needs to be replaced. I hope you the have MCB turned off? It's very dangerous at the moment with the pin from the plug still in the socket.

salad17 · 14-03-2020 3:35pm

Doolittle51 wrote: »

That plug looks very old. A couple of things could have caused the issue. The cable size could be too small for the fuse. Could have been a loose screw causing arching. Insulation could have been in bad condition.
Either way, you should try to plug the dryer directly into the socket without the need for an extension lead. Also, it's not a good idea to have the dryer and the washing machine on at the same time, plugged into the same socket.

Obviously the socket needs to be replaced. I hope you the have MCB turned off? It's very dangerous at the moment with the pin from the plug still in the socket.

Thanks for the reply.

Yes MCB is turned off. But we ran an different extension chord from a different part of the house (ie different outlet) and had the same problem, running just the dryer on its own! Coincidence? 2 bad plugs?

So straight into the wall outlet is safer? Yeah I can get that it’s a lot of power but aren’t washers and dryers very often next to each other and so plugged into the same outlet?

brightspark · 14-03-2020 4:34pm

Did you fit a new plug top when you replaced the extension lead?

(as others have said using extension leads with high power appliances is not advisable)

Doolittle51 · 14-03-2020 5:17pm

salad17 wrote: »

Thanks for the reply.

Yes MCB is turned off. But we ran an different extension chord from a different part of the house (ie different outlet) and had the same problem, running just the dryer on its own! Coincidence? 2 bad plugs?

So straight into the wall outlet is safer? Yeah I can get that it’s a lot of power but aren’t washers and dryers very often next to each other and so plugged into the same outlet?

True, a lot of people would have their washing machine and dryer plugged into the same double socket which should be on a circuit protected by a 20 amp MCB or fuse. However, some double sockets aren't actually suitable for use above 13 amps. Running 2 high powered appliances at the same time on the same socket or extension lead should be avoided. Also, fuses can take a lot of abuse before they blow. So you could have been pushing the limits a bit too much. A poorly terminated cable in the plug could give up before the fuse blows. If, for example some strands of cable were snipped when the cable was stripped, now you have a weak point.

Were both of the extension leads quite old?
Were you using both appliances at the same time on one extension lead?
Compare the cable on the extension lead to that of your dryer or washing machine - does it seem a lot smaller?

salad17 · 14-03-2020 9:49pm

I didn’t just change the melted plug, I used a whole new extension lead.

Doolittle51 wrote: »

True, a lot of people would have their washing machine and dryer plugged into the same double socket which should be on a circuit protected by a 20 amp MCB or fuse. However, some double sockets aren't actually suitable for use above 13 amps. Running 2 high powered appliances at the same time on the same socket or extension lead should be avoided. Also, fuses can take a lot of abuse before they blow. So you could have been pushing the limits a bit too much. A poorly terminated cable in the plug could give up before the fuse blows. If, for example some strands of cable were snipped when the cable was stripped, now you have a weak point.

Were both of the extension leads quite old?
Were you using both appliances at the same time on one extension lead?
Compare the cable on the extension lead to that of your dryer or washing machine - does it seem a lot smaller?

Interesting, I never got why we should use different outlets anyway since all the downstairs outlets tend to be on the same MCB. And I thought plugging in an extension chord meant that was then protected at the lower amount of the fuse in that plug, but it doesn’t actually usually blow if it goes over that many amps?

I guess the cables were old yeah, maybe 5 years.

The first time both appliances, the second time just the dryer on its own. I will have a look at the wire thickness.

It seems incredibly dangerous and likely to cause a fire if it takes so little as those suggestions to do that. I would imagine one could quite commonly use different thickness cables, or use extension chords, or not know about an old connection..

brightspark · 14-03-2020 9:58pm

salad17 wrote: »

I didn’t just change the melted plug, I used a whole new extension lead.

Interesting, I never got why we should use different outlets anyway since all the downstairs outlets tend to be on the same MCB. And I thought plugging in an extension chord meant that was then protected at the lower amount of the fuse in that plug, but it doesn’t actually usually blow if it goes over that many amps?

I guess the cables were old yeah, maybe 5 years.

The first time both appliances, the second time just the dryer on its own. I will have a look at the wire thickness.

It seems incredibly dangerous and likely to cause a fire if it takes so little as those suggestions to do that. I would imagine one could quite commonly use different thickness cables, or use extension chords, or not know about an old connection..

The damage in the photos indicates poor connections, the load probably never exceeded the 13A by much anyway (A 13A fuse won't blow at 13A https://www.pat-testing-training.net/articles/fuse-operation-characteristics.php )

However many extension leads are cheaply made and are probably not able to sustain even 13A without getting damaged.

Johnboy1951 · 15-03-2020 12:23am

Based on the pics I viewed, the problem seemed to have been either a loose fuse or a loose wire.

If either are not tight, then the joint will heat and can heat so much as to cause melting of the plastic.

The melting seems to be in that location.

ZENER · 19-03-2020 10:24am

Also if it's a roll up type extension lead be sure the whole of the cable is unwound from the reel. Aside from that unless it's a good quality lead then it probably isn't designed for running high loads over extended periods.

Ken

Melting plug sockets

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