Dangerous Arcing?

[nabby68]

Hi
My daughter purchased a brand new condensing tumble dryer. She decided to use it plugged into a socket in the dining room whilst room was made for it to be fitted into her kitchen.
After using it for the second time she smelt a burning smell and immediatley turned the appliance off. She then noticed that she was unable to remove the plug from the socket. Her boyfriend managed to jemmy the plug away from the socket and noticed that the plug showed signs of charring and melting around the neutral pin also charring and damage around the hole in the socket where the neutral pin goes into (pics supplied) After telling her to isolate the electrics i called down to investigate the damage. After loosening the screws around the socket and carefully pulling the socket away from the wall i noticed that this was a spur and there was considerable charring and melting on the neutral wire (possible arcing). The socket was spurred from an adjacent socket on the other side of the wall. After loosening the screws on that socket also i slowly pulled the socket away from the wall and the three single phase connections came out of the terminal connection, they had not been tightened at all! Could this contribute to the arcing on the neutral wire on the spur?

 

[Gerrydelasel]

Definitely. There will have been minimal contact area between the terminal and the loose copper wire, creating a high-resistance point that would get hot / melt / expand / move etc.

 

[nabby68]

So the solution would be to correct the loose wires in the socket on the ring main and then renew the wiring for the damaged spur?

 

[PrenticeBoyofDerry]

Solution would be:
If enough slack on existing damaged conductors, to remove the burnt section of conductor until clean copper is found. Then replace damaged socket outlet and then terminate conductors.
If damage to cable is extensive then it should be replaced, if you find good conductor but length too short, it can be extended within the backbox.

The above is assuming the circuit cable is correctly sized for the spur and the spur is the only unfused spur of a ring final circuit.

 

[endecotp]

The socket was spurred from an adjacent socket on the other side of the wall. After loosening the screws on that socket also i slowly pulled the socket away from the wall and the three single phase connections came out of the terminal connection, they had not been tightened at all! Could this contribute to the arcing on the neutral wire on the spur?

It's not clear to me how a bad live connection in one place can lead to an overheating neutral at a different connection further downstream.
I'd say it's more likely that the other connection - presumably installed by the same person - was also loose, though perhaps not loose enough for you to notice. Unless you have reason to think that this spur was installed as a one-off, I suggest that you check all other sockets for similar issues. And test the smoke alarms!