Melted socket, plug and wiring

[strength_10]

Hello. Long time reader but not many posts. After more of a bit of insight than anything else as I have asked for a local electrician to come and have a look next week (unless anyone reading is near BS39 in Bristol/Bath and wants to have a look).

I have a washing machine (couple of weeks old as previous one had bearings failing) and a tumble dryer in my utility room. Both appliances are individually plugged into single sockets under the counter which are separately fed from 2 FCU above the worktops. Both FCU are fitted with 13A fuses. Have been happily (I think) like that for 6 years since the house was rewired and had new consumer unit fitted just after we moved in and had solar panels installed.

Couple of days ago washing machine stopped working. Assumed it was an unlucky new appliance to Samsung sent out an engineer. He spotted (quickly) that the plug was damaged and the socket starting to melt through. He then spotted that tumble dryer plug was even worse and socket properly melted through. Good news is the new washing machine doesn't seem to be broken after all. Bad news is both sockets and both appliance plugs are broken. I removed the fuses from FCU, isolated the MCB and unscrewed the sockets to find wiring inside is blackened and a bit melted.

Obviously I'll need the wiring and sockets replaced and the circuits tested but I'm after a bit of insight (I appreciate it's a bit of guesswork from afar) as to:

a) what causes this sort of damage?
b) why it may have happened to 2 separate sockets and plugs being fed from 2 different FCU feeds in short succession?

Thanks in advance,
Cameron

 

[Octopus]

Unfortunately this happens all too often these days ............. poor quality sockets and / or poor terminated cables in the sockets and / or poor plugs and connections

 

[Dillb]

Are both appliances from the same manufacturer?

I would say that looking at that, there is a loose connection ok the circuit/s somewhere. Are they both on the same circuit?

 

[strength_10]

Are both appliances from the same manufacturer?

I would say that looking at that, there is a loose connection ok the circuit/s somewhere. Are they both on the same circuit?

Hi. No, washing machine is brand new Samsung and tumble dryer is 3 year old Hotpoint. Both sockets are on same 32A ring but each socket is fed from a separate 13A FCU on that ring with it's own cable between the FCU and socket (hope that makes sense).

Thanks,

 

[Dillb]

Hi. No, washing machine is brand new Samsung and tumble dryer is 3 year old Hotpoint. Both sockets are on same 32A ring but each socket is fed from a separate 13A FCU on that ring with it's own cable between the FCU and socket (hope that makes sense).

Thanks,

No that makes sense. My money is on a loose connection on the circuit then.

 

[strength_10]

No that makes sense. My money is on a loose connection on the circuit then.

Thanks. Do you mean loose connection(s) at the sockets the appliances were using (and just bad luck the both of them at similar time) or could the loose connection be somewhere else on the ring that somehow manifests itself at those sockets? As you can tell I know little about electrics but would like to understand.

 

[Dillb]

Thanks. Do you mean loose connection(s) at the sockets the appliances were using (and just bad luck the both of them at similar time) or could the loose connection be somewhere else on the ring that somehow manifests itself at those sockets? As you can tell I know little about electrics but would like to understand.

It could be anywhere on the circuit, without the correct test equipment it would be near on impossible to find out where.

 

[strength_10]

It could be anywhere on the circuit, without the correct test equipment it would be near on impossible to find out where.

Thanks, I'll await an electrician finding the fault then. Thanks for the input.

 

[westward10]

Go on eBay and get some 1970s sockets and plugs, get a sparky to fit them and it will never happen again.

 

[Lucien Nunes]

I would say the problem is localised to the particular sockets, and whilst melted plug / socket pairs are often caused by a problem in the plug, in this case it does look more like the sockets. Either poor manufacturing causing high resistance contacts, or bad workmanship in terminating the circuit cables. Seeing the back of the socket would probably reveal which of these scenarios.

My reasoning is that the heat pattern is the same in both cases, one on the line and one on the neutral, and reflects the layout of the metal parts within the socket. The internal construction of plugs is quite different between line and neutral, and in a decent moulded plug there is little chance of a high resistance in the neutral.

If there are more of these sockets around the house, or more of the same person's work (as the case may be), then there may be more burnouts to come on heavily loaded sockets, unless they are replaced / rewired.

 

[MJPD29]

Get a few old mk single sockets off eBay as above and problem solved

 

[strength_10]

I would say the problem is localised to the particular sockets, and whilst melted plug / socket pairs are often caused by a problem in the plug, in this case it does look more like the sockets. Either poor manufacturing causing high resistance contacts, or bad workmanship in terminating the circuit cables. Seeing the back of the socket would probably reveal which of these scenarios.

My reasoning is that the heat pattern is the same in both cases, one on the line and one on the neutral, and reflects the layout of the metal parts within the socket. The internal construction of plugs is quite different between line and neutral, and in a decent moulded plug there is little chance of a high resistance in the neutral.

If there are more of these sockets around the house, or more of the same person's work (as the case may be), then there may be more burnouts to come on heavily loaded sockets, unless they are replaced / rewired.

Thanks. Pictures of rear of each socket below. Fortunately (maybe, if that is the problem) these are probably the only 2 of this make and done by this installer as after he'd done the rewire I then (about a year later) got all the fixtures replaced with brushed chrome ones (different installer as couldn't contact original person) but left these two as they were behind appliances.

 

[MJPD29]

If they are LAP or another poor quality make they won't be up to standard as I have seen so many times before

 

[strength_10]

If they are LAP or another poor quality make they won't be up to standard as I have seen so many times before

Thanks, can't see a brand on them at all.

 

[strength_10]

On a different note, is there any benefit in asking for the replacements to be flex outlets as they are fixed appliances which don't really get moved rather than plug and sockets?