Non-motoring > Home Electric Problems Miscellaneous
Thread Author: zippy Replies: 5
View Threaded 

New Mon 4 Jan 21 19:19 
 Home Electric Problems - zippy
Went in to the kitchen to find the kettle not working.

Went to unplug it and the plug is stuck in the socket.

Isolated the mains and pulled the plug out - it was incredibly stiff.

Glad I isolated the mains because the bottom left pin is charred and the the black insulation around the pin has evaporated in places.

The fuse appears to be fine.

The kettle is from a major UK brand purchased from Amazon as Amazon (not a 3rd party).

The socket is a major brand - but installed with the house. It also has those silly USB things attached.

I need to establish:

1. What caused the burnt / stuck plug.
2. why the fuse didn't blow.
3. why the mains didn't trip (RCD fuse box fitted).

Any ideas appreciated please.
Reply to this message | Report message
       
New Mon 4 Jan 21 19:26 
 Home Electric Problems - Manatee
1. Heat. Generated by resistance as a result of poor contact.
2. Because there was no excess current
3. Because there was no current leakage - the supply and return current were balanced.

It was resistive heating in a junction box that caused my house fire, in all probability.

But why the poor contact? It's not that unusual, I've seen quite a few burnt-looking plugs and sockets over the years. Suggest you replace both.
Last edited by: Manatee on Mon 4 Jan 21 at 19:28
Reply to this message | Report message
       
New Mon 4 Jan 21 19:33 
 Home Electric Problems - Zero
>> 1. Heat. Generated by resistance as a result of poor contact.

Assuming the plug is moulded on: 1, was caused by a poor physical contact connection where the pin of the plug goes into the socket, or the wire connection on the socket is loose, if not tightened sufficiently you get thermal fretting, and the joint gets looser.

either way plug and socket need changing.
Reply to this message | Report message
       
New Mon 4 Jan 21 22:41 
 Home Electric Problems - bathtub tom
I've experienced this sort of thing when:
1. The fuse is loose in the contact springs (one leg of the fuse connects directly to the live pin).
2. The wires in the live or neutral pin become loose because they compress under the screw holding them down.

Both cases I suspect are due to repeated heating/cooling from the current drawn.
Reply to this message | Report message
       
New Mon 4 Jan 21 22:57 
 Home Electric Problems - Manatee

>> Both cases I suspect are due to repeated heating/cooling from the current drawn.

I think so too. so did the forensic examiner who came to investigate after the house fire. He also though mains AC sets up a low energy hum or vibration that loosens connections over a long period. We've all probably had the experience of taking a plug off an old appliance before we disposed of it and finding the screws in the plug are loose.

As the kettle was new, maybe this plug just wasn't assembled correctly in the first place.
Last edited by: Manatee on Mon 4 Jan 21 at 23:00
Reply to this message | Report message
       
New Tue 5 Jan 21 01:15 
 Home Electric Problems - Fullchat
Likewise if you fit a new socket and fasten the wire clamping screws. Go back 30 minutes later and you will get a bit more of a turn on the screw. I can only assume the solid copper wire slowly compresses.
Reply to this message | Report message
       
Latest Forum Posts