Sparky/electrical advice needed

[danielf]

Our dishwasher stopped working today. At first it wouldn't switch on (none of the lights came on), after fiddling with the switches for a bit it did, but it didn't finish the programme. The fuse above the counter which feeds the socket below the counter was fine (worked in another socket), so I started looking at the actual socket (below the counter) where the plug goes. I spent a good half hour trying to get the plug out of the socket, and by the time I got it out, it was apparent why it wouldn't come out. Some of the plastic on one of the pins had molten, and there are some nice black marks around the hole that pin goes in.

It seems to me that (at the very least) I have a faulty socket that needs replacing. I'm wondering though, is it likely to be indicative of a deeper problem, or is a faulty socket the most likely culprit? Also, I am assuming that some fuse (perhaps the fuse in the plug) will have blown, but I still find it strange that so much heat was generated that part of the pin melted. Should fuses not blow to prevent this from happening?

Ta for any input :)

Oh, the dishwasher itself is brand new. We replaced it when the previous one stopped working due to an 'unidentified electrical problem' :dunce: :p:

Edit: I'm not sure if this is in the right forum. If not, could a kind mod please move it to 'current affairs'? :)

[Tali]

I've had a similar problem when using one of the 'newer' type plugs (with the black plastic insulation to stop small fingers touching the metal of a partially inserted plug) in an extension lead.

I found that the plug and socket had melted together. The heat was being generated from the electricity arcing from the connection in the socket to the plug. I replaced the socket and haven't had any problems since. I guess the fuse didn't blow because there wasn't a short or the circuit didn't go to ground/earth. Don't believe me though, I don't know what I'm talking about!

[soup dragon]

has a wire come loose in the plug? if it is a new appliance then the plug is probably sealed so you would need to cut the plug off and put a new one on!

open the socket to check the wires inside, again one could be loose in there. It will be obvious if there is. If you need to change it then it is easy enough to swap, just remember the wires are a different colour in the mains, red = live, black = neutral:)

[altis]

Just sounds like a poor connection (eg dirt) between the plug and socket. Because of the large current flowing to dishwasher (big heater) any small resistance in the supply wil generate lots of heat. In a confined space like a plug and socket this can eventually cause damage. The plug will have a 13A fuse but currents less than this can still cause problems in the wrong place.

I suggest:
1) use good quality plugs and sockets from a reputable manufacturer
2) occasionally remove every plug from its socket to:
-a) inspect the pins
-b) cause the contacts to rub against each other and clean themselves

I wonder if the previous 'unidentified electrical problem' was caused by the same thing. Perhaps the supply to the dishwasher dropped so much when the heater came on that the electronics/timer stopped working.

PS: Since 2006 *all* new wiring (including fixed) should be brown for live and blue for neutral in accordance with IEC60446:
http://en.wikipedia.org/wiki/IEC_60446
http://www.iee.org/Publish/WireRegs/IEE_Harmonized_colours.pdf

[Noggo]

Does sound like a dodgy socket / plug connection. My sister had one go similar to what you are describing a couple a years ago. In her case I replaced both the socket and the plug and it's been fine since. As yours is a new dishwasher it will have a moulded plug and if you cut this off you may void the warranty.

All I can suggest is go for a good make like `MK' and not any of the B&Q, Focus or Homebase etc home brand options. I got the MK ones I used from Focus.

[bopdude]

Most probable cause IMHO is that the wires to the socket terminals are not tight, this 'slack' connection increases the the current and thus creates heat, seen it many a time. Check it / or get it checked out, as well as the socket, check the insulation on the wires, these in some / most cases will have been damaged by the heat generated.

HTH's