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Discussion Starter #1
Hi
spotted a new leaf charging at a public fast charger through a coiled up lead.
it was taped together with earthing tape to keep it tidy presumably.
I thought this would cause overheating?
I touched the coil and it seemed ambient temperature.
the screen said it was charging.

is there some sort of thermistor in the lead that prevents over-heating?
I would never do this.
 

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Not ideal, but a loose coil still has plenty of air circulating all around it. Very different to an enclosed wind-up, or drum type where there are a large number of turns closely spaced.
Charge cables also tend to be properly specced for their current rating, unlike cheapo domestic ones which often have bare-minnimum or less conductor sizes.
 

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A friend of mine melted his 13-amp extension coil by using it with an EVSE for a number of hours without uncoiling it! The outer insulation fused together, preventing it from being uncoiled. Nothing tripped out, and the charge was still running when he realised what was happening and killed the power.
 

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A friend of mine melted his 13-amp extension coil by using it with an EVSE for a number of hours without uncoiling it! The outer insulation fused together, preventing it from being uncoiled. Nothing tripped out, and the charge was still running when he realised what was happening and killed the power.
Completely different scenario, for the reasons I have repeated here many many times.
 

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Completely different scenario, for the reasons I have repeated here many many times.
I do apologise. Let me go off an read your previous posts and try to find what you’re talking about. Something about how 32/16-amp single phased AC coiled cable is completely different to 13-amp single phase AC coiled cable. Shouldn’t take long, since you’ve only got around 23k postings to this site. Must be a full-time job sharing your wisdom, it will take me a while to catch-up.
 

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I probably need to start writing blogs rather than posts.

Heat is mainly generated in the pins.

Not much heat generated in Type 2 pins.

Lots of heat generated in 3 pin sockets.

Cables get hot if there is heat trying to get out somewhere, the cables are the heat sinks to the pins/plugs.

Good thermal impedance at the pins means ohmic resistance heat can escape the cable, and also implies good electrical impedance and little heat to be sunk to elsewhere.

Bad thermal impedance at the pins means ohmic resistance heat may struggle to escape the cable, and also implies bad electrical impedance so there may be lots of heat actually trying to get into the extension cable, rather than getting out.

HTH
 

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Discussion Starter #13
I was surprised it was still cool. leaf40 is 7kw charge and it had been going for at least 30mins probably longer. The cable was tightly coiled and taped to stop it uncoiling.
 

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I’ve also seen a Leaf owner plugging in with a taped coiled lead. I assumed he was a new owner, turned out he’d been doing this for about a year. Would worry me, but it sounds like the physics is in his side.
 

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I often leave my Type 2 cable coiled up when charging as it sits neatly under the car.

I’ve never noticed it warm up. Might have to put a blanket on it next time.
 

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This thread is discussing heat in coiled cables, you are talking about hot 13A plugs.
So
you are right, but you are in the wrong place.
Why are you telling me that? I was replying to @DougM. Why do you think I posted as I did in #7?

Sheesh. Pick the biggest target and aim for that, even if it is a 'friendly'.
 

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Why are you telling me that? I was replying to @DougM. Why do you think I posted as I did in #7?

Sheesh. Pick the biggest target and aim for that, even if it is a 'friendly'.
He was describing an extension melted from being used while coiled. Nothing whatever to do with hot pins in plugs.

That it was you that began a confusing and irrelevant side-line was beside the point - I'd have pointed it up to anyone else too.
 

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He was describing an extension melted from being used while coiled. Nothing whatever to do with hot pins in plugs.

That it was you that began a confusing and irrelevant side-line was beside the point - I'd have pointed it up to anyone else too.
If there was no heat from the plug I doubt the cable would melt. You are making an assumption there that the ohmic resistance of the cable rather than the contact resistance of the pins at the ends is the only possible cause.

If the thermal impedance of the pins is poor it means a temperature gradient can build up easily back into the cable length. If there is good thermal conductance at the end of the cable then the thermal power can sink into the cabling on the other side of the plug.

It is the same issue.
 

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I usually use my T2-T2 cable coiled, with the coils held together at 2 points of the circle (so nothing too tight). The cable is rated 32A and 5m long while most of the time I only need 1.5m long, so it helps keeping things tidy, and makes it easier to take in and out.

After 2 hours charging, the cable is sometimes slightly warm (I don't think more than 5 degrees above current temperature).

I wanted to buy a 1.5-2m charging cable, but that's not standard and all I could find was more than I wanted to spend just to keep things tidier. So I've been using my coiled 5m cable for 4 years, checking regularly on the temperature, and never noticing anything near alarming.
 
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