Overheated extension reel

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Monmouthshire
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Mrs lost decided to to do some pressure washing, 3kw, with the wrong extension and not unwound ,in my absence and knocked a breaker out when the reel melted:eek:
 

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I remember a woman in our office way back in the 1980s putting a 3kw fan heater on a fully wound extension under her desk. The whole thing duly melted and filled the place with acrid smoke.
I recall that we all found it quite amusing at the time. She was a bit of a know it all and the whole incident effectively took her down a peg or two.
Thinking back is a miracle she didn’t burn the place down.
 
Got to say that not many people know about the different capacity of wound or unwound reels.
There should be a big prominent red mark that people don't miss.
 
Most reels you come across for sale these days have a block of text telling you to unwind fully before use.
It's getting people to read it thats the problem. Same as those people who go to a hardware shop, (in fact any shop that sells them, including supermarkets), and just pick one up without checking the rating. Woman next to my daughter used a reel on her tumble-dryer and asked my daughter if I would have a look at it, ("because it was getting quite hot even though she had unwound it"). I asked my daughter to read out what it said on the socket face of the reel. She said, "15 metres Unwind fully before use." I asked if there was a 10A or 13A anywhere on it and she replied, "Yes, it says 10A."
So I told her, it needs one with 13A on it and it should only be as long as the distance between the dryer and the socket and preferably no more than 2 metres. Also recommended she try to find one that has 2.5mm written on it as opposed to 1.5mm
 
My wife and I ran a B&B until recently. You quickly realise that many people simply don’t read anything.

We had a saniflo toilet in one room, we had two notices telling people to be careful what they put down the loo but to no avail. I lost count of the times I had the thing apart cutting off sanitary towels (or worse) wrapped around the cutting blades. Lovely!
 
I think these days, hotels, B&B's etc have to provide a separate special bin for these things.
When you put something in, it lands on a ledge then drops down when the lid shuts. It also helps form a seal when it's opened and the top lid seals when it's closed.
 
I think these days, hotels, B&B's etc have to provide a separate special bin for these things.
When you put something in, it lands on a ledge then drops down when the lid shuts. It also helps form a seal when it's opened and the top lid seals when it's closed.
We did. People still ignored the bins and chucked everything down the loo.
My more general point is that some people just don't read notices. If they can ignore this, then getting those same people to look at the warnings on extension reels is a lost cause.
 
My point was that the warning is not prominent enough.
I have 3 reels and the "instructions" are in small print.
The brand and lenght however are in big bold letters.
 
This is the sort of stuff that should be taught in schools. There might be warning labels on extension cables but they usually assume some basic understanding of amps, watts etc. that not everyone has.
 
That plug top is potentially lethal, unsheathed pins were banned in the UK years ago
 
Re: the overheating, why?

Is it that the cable itself has a small degree of resistance and, while this would be negligible due to dissipation while unwound, it would build up if coiled?

Would a cable still overheat when under load of it was just bundled in a haphazard pile, or is it something about it being in a coil that causes it?
 
Is it that the cable itself has a small degree of resistance
Indeed, every cable has resistance.

and, while this would be negligible due to dissipation while unwound, it would build up if coiled?
Pretty much, same amount of heat generated but less ability to disspate heat means higher equilibrium temperature.

IIRC cable ratings are typically based around a cable working temperature of around 70C.

Would a cable still overheat when under load of it was just bundled in a haphazard pile, or is it something about it being in a coil that causes it?
It's far less likely, because the "haphazard pile" will nearly always be far more spread out than cable wound on a reel.
 
Aren‘t UK reels required to have a thermal cutout? I haven‘t seen a new reel without one on the continent for a long, long time.
 
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