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An image of an opened AC plug, with three wires

The red copper wire was burned so I took out the burnt part of the wire and reinserted all the wires by myself.

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  • 18
    Why is the bare part of the red wire sticking way out and through like that? Why isn't it like the others? May 13 '20 at 23:31
  • 8
    Please provide a picture of the finished result. There are currently three serious errors which need to be confirmed as having been corrected before it can be deemed safe.
    – Tetsujin
    May 14 '20 at 7:56
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    For safety reasons make sure the ground (yellow/green wire) is longer than the other two. In case someone pulls on the cable the ground wire should always be the last one which fails.
    – Michael
    May 14 '20 at 10:57
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    @Carl I'd say it's a plug, since it's on the end of a wire and appears to have prongs rather than holes (I assume - not familiar with UK electrical and we can only see the back of this one.) To me (US English) a socket is interchangeable with outlet or receptacle - it's a hole that something goes into, not something that goes into a hole. (Think "eye socket", "ball and socket", "socket wrench", etc.) May 14 '20 at 18:57
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    You should also make sure you know why the wire burned in the first place and make sure the situation cannot repeat.
    – Jeffrey
    May 15 '20 at 3:21
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You should trim the extra copper off it will not help to have it hanging out there. You also need to make sure when you put things back together the clamp is on the covering for the cable not the individual wires but other than those items I would say it looks safe. A proper torque would be needed to be 100%.

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    make sure all the clamps are tight. chances are the red one came loose, thus the reason it arced.
    – Scott
    May 14 '20 at 0:27
  • It looks like there was some solder on the other wires - never seen a setup like that (screw terminal + solder) - maybe it helps hold it in place? May 14 '20 at 8:02
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    If the wires have solder on them, then they should be trimmed back to bare wire. Solder + screw joints is a very bad idea because the solder will (slowly) flow, thereby loosening the joint over time and allowing arcing. In fact as the remaining wires appear to possibly have solder on them, this is probably what caused the fault in the first place.
    – SiHa
    May 14 '20 at 11:10
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That plug needs redoing. Urgently. It is unsafe.

Make sure the clamp is on the covering for the cable not the individual wires

This is a correctly wired UK plug... different live & neutral colours and there's a fuse, but you get the idea that the cable grip goes over the outer covering of the cable and is properly tightened. The exposed power wires (red and black in your picture) should be only as long as they need to be to reach the plug pins, no longer. The earth/ground wire (green & yellow) should be a little longer, so it gets pulled out last if the cable grip fails. The bared copper should also be the minimum length needed to get under the screws, which should be fully tightened.

enter image description here

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    & +2 for actually bothering to cut each wire to the correct length. I've even seen factory-made ones with all the same length, crammed in.
    – Tetsujin
    May 14 '20 at 7:52
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    Actually, for a UK plug, I think that while the live and neutral (brown and blue) wires should be no longer than needed, the earth (green/yellow) should have a little slack. (As the picture demonstrates.) That way, if the cable is pulled strongly enough for the clamp to fail, the live and neutral will disconnect before the earth.
    – gidds
    May 14 '20 at 10:26
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    I think it is a BS546 plug which are rarely used in the UK now. Sometimes they are used for sockets connected to the central lighting circuit which are controlled by the main light switch. It is most likely a 5A plug though. I'm wondering if the burning was caused by the plug being put on a device which draws higher current (eg 13A heater)
    – mpursuit
    May 14 '20 at 13:43
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    The OP's plug is very probably an Indian Type D, not a UK plug at all. worldstandards.eu/electricity/plugs-and-sockets/d The Type D is, in fact, the old UK BS 546.
    – Tetsujin
    May 14 '20 at 13:45
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    Indian Type D are BS546 which were standard in the UK till 1947 when the square pin (BS 1363) was introduced. They are still used rarely in the UK.
    – mpursuit
    May 14 '20 at 13:49
2

It would be a cleaner installation to not allow the wire to stick out very far on the far side (looking at you red wire). Make sure that there is only copper under the clamp for the red wire and no insulation under the screw and cramp (it looks like it's pushed in too far)

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  • The comment about insulation seems to contradict the other answers
    – Kai
    May 14 '20 at 13:37
  • People may be using ‘clamp’ to mean different things… The screw-down strip at the bottom of the plug that holds the whole cable in place (which is what I'd call the clamp) should go over the white outer insulation, not the separate coloured insulation on each wire. But the terminal pins and their screws should hold only bare wire, not insulation (and, as someone else pointed out, not even solder).
    – gidds
    May 14 '20 at 14:51
  • yes thanks @gidds for clarifying the words I used, I do mean that bare wire should be under the terminal pins
    – Ack
    May 14 '20 at 14:57
  • @gidds - "The screw-down strip at the bottom of the plug that holds the whole cable in place (which is what I'd call the clamp) - called the 'cable grip' in this context in the UK May 14 '20 at 20:31
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The wires are way too long, they need to be shortened and the sheath of the flex needs to be secured under the cord grip. The stripped section at the end of the wire should be long enough that the screw can properly clamp down on it but not excessively long.

Ideally the live wire should have no slack the neutral wire a medium amount of slack and the earth wire should have the most slack. This way in the unlikely event that the cord grip fails and the cable gets ripped out of the plug the wires should become disconnected in the safest possible order.

Also personally I would not reuse a plug that had shown signs of heat damage.

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