What happened here?

[Steve T]

Hi,

Bit of a strange one today, was using a single socket extension lead and I plugged my hoover into it, turned it on and it started up very briefly before the power to it was cut. Checked if it had tripped an MCB, nope. Next check was the fuse in the plug, thought maybe it was the wrong size and hoover had overloaded it, nope was a 13A fuse and it had not blown. Strange. Plugged my hoover into a socket by itself and worked no problem, so tried it in the extension lead again, nothing. I then took apart the socket on the extension lead and found this: (I would like to point out I haven't personally put together this extension lead, not sure if it's a DIY one or shop bought, it's fairly old)

It was just about still working as it looks like a couple of strands of the live wire were touching the terminal. So the live and earth have clearly been pulled somehow so hard that the wires snapped or were pulled out of the terminals, terminals were not loose by the way. Strange thing is the neutral still has much more slack on it. Also it doesn't look like the whole cable has been pulled out, the cord grip is very tight and there are no cord grip marks further up the cable.

How is it possible for two of the three wires only to have been pulled out of their terminals?? Could winding the cable around something cause this?

Would be interesting to hear your thoughts!

 

[littlespark]

Even older extension leads made up in a factory have crimped ends.

Looks like this one is a diy job, maybe it got hacked in the past and was shortened?

earth isn’t even touching

check the plug end as well and post a photo…

 

[Pete999]

Hi,

Bit of a strange one today, was using a single socket extension lead and I plugged my hoover into it, turned it on and it started up very briefly before the power to it was cut. Checked if it had tripped an MCB, nope. Next check was the fuse in the plug, thought maybe it was the wrong size and hoover had overloaded it, nope was a 13A fuse and it had not blown. Strange. Plugged my hoover into a socket by itself and worked no problem, so tried it in the extension lead again, nothing. I then took apart the socket on the extension lead and found this: (I would like to point out I haven't personally put together this extension lead, not sure if it's a DIY one or shop bought, it's fairly old)
View attachment 87818View attachment 87819

It was just about still working as it looks like a couple of strands of the live wire were touching the terminal. So the live and earth have clearly been pulled somehow so hard that the wires snapped or were pulled out of the terminals, terminals were not loose by the way. Strange thing is the neutral still has much more slack on it. Also it doesn't look like the whole cable has been pulled out, the cord grip is very tight and there are no cord grip marks further up the cable.

How is it possible for two of the three wires only to have been pulled out of their terminals?? Could winding the cable around something cause this?

Would be interesting to hear your thoughts!

User ddn't have any idea of how to strip the cores

 

[brianmoooore]

It has failed because it was very badly put together in the first place. The earth wire should have been left with plenty of slack and the live with very little. The neutral should have been somewhere in the middle.

 

[Steve T]

Even older extension leads made up in a factory have crimped ends.

Looks like this one is a diy job, maybe it got hacked in the past and was shortened?

earth isn’t even touching

check the plug end as well and post a photo…

You're probably right about being a diy job, earth looks too short on the plug as well. Still confused as to why the neutral in the socket had so much more slack, maybe stripped to inconsistent lengths?

 

[ipf]

It's a shame but 'if it works, it works' is the general ideology.

As most in the trade know, there are tens of thousands of such examples throughout the country.

 

[static zap]

I always preferred Long Neutral and Earth for socket ends.
...
Have also seen a few strands tucked under as a fuse --eek.
( strange no heating devices - hidden fuses .. is end result)
..or a Fire !
The If it works is scarily true - until " Pat-test"... Insert
" NEW name here " ! came to educate others at work !

(TIN hat ..ON .with extra Zip ties )

 

[pc1966]

The 13A plug is not too bad, a touch short but otherwise not the worst I have seen by a long way.

The socket end is appalling and hard to see how anyone could have put that together without realising it was hopeless. As pointed out above, the earth should always have a touch more slack then the other conductors as it is the last one you want to come adrift. Same basic idea as why the 13A plug has a longer earth pin - so it mates first and disconnects last.

While few do it, putting ferrules on the fine-stranded wire for 13A plugs/sockets is good practice, kits for the insulated ones are fairly cheap like this:

https://www.amazon.co.uk/Preciva-CP621200-Crimper-Self-adjustable-Crimping/dp/B073TZ5BBG/

But for most 13A things the insulated sleeve gets in the way so you really want the uninsulated ones such as these:

97 99 910 | Knipex Crimp terminal Kit | RS

uk.rs-online.com

Though realistically for most cases having 1.5mm for extension leads and maybe 0.75mm for lights is enough and you can get them in small bags separately.

Or if you have the insulated ones cut the plastic off if only a couple needed...

 

[Steve T]

The 13A plug is not too bad, a touch short but otherwise not the worst I have seen by a long way.

The socket end is appalling and hard to see how anyone could have put that together without realising it was hopeless. As pointed out above, the earth should always have a touch more slack then the other conductors as it is the last one you want to come adrift. Same basic idea as why the 13A plug has a longer earth pin - so it mates first and disconnects last.

While few do it, putting ferrules on the fine-stranded wire for 13A plugs/sockets is good practice, kits for the insulated ones are fairly cheap like this:

https://www.amazon.co.uk/Preciva-CP621200-Crimper-Self-adjustable-Crimping/dp/B073TZ5BBG/

But for most 13A things the insulated sleeve gets in the way so you really want the uninsulated ones such as these:

97 99 910 | Knipex Crimp terminal Kit | RS

uk.rs-online.com

Though realistically for most cases having 1.5mm for extension leads and maybe 0.75mm for lights is enough and you can get them in small bags separately.

Or if you have the insulated ones cut the plastic off if only a couple needed...

I guess they must have had the earth and live so short that the slightest hard pull on the cable managed to pull them put, without pulling the actual cable out of the grip. Anyway I've remade off both ends, using (insulated) ferrules with the plastic part cut off, and have left the earth much longer than all the other conductors, so should be much safer now!

 

[Mikegh]