easy reel...

[Vskødäjéllÿ]

my arse!

[Vskødäjéllÿ]

?id=15712&p=x4&cm_re=CROSS_SELL-_-SLOT1-_-15712&catId=PRODUCT_DETAILS&ts=33507&destination=/app/sfd/cat/pro.jsp%3Fid%3D15712%26p%3Dx4#

What do you think of this?

I'm looking to replace one that says on the label...

50 m cable, H05vv-f 3G 1.5mm [squared] (can't remember the alt + for that little 2...)

Reeled max 1.000W 230V Unreeled max 3.000W 230V

Any info gratefully received please :-) Ta

[EricP]

It's the same length and much higher current at 13 amp up from 5 amp. (Using plug ratings)

Although you will have to unwind most of it to use at 13 amp.

Whats the problem?

[EricP]

Yes dear. And a very nice arse it is too!

A bit lumpy and saggy in places, but comfy to sit on.

VupholsteredJ

[the_constructor]

?id=15712&p=x4&cm_re=CROSS_SELL-_-SLOT1-_-15712&catId=PRODUCT_DETAILS&ts=33507&destination=/app/sfd/cat/pro.jsp%3Fid%3D15712%26p%3Dx4#>

You should never ever usee an extension cable that is coiled on a drum, due to the electric field that it producers. I remember years and years ago when I first started my training in electrics that I would my extension lead round an old cable drum. Only wanting a short lead to do a job a little later, I took just enough off the drum and plugged in the lead. Going back to the drum a little later it was red hot and some of the cable was melting.

[Palindrome]

I think that you will find that it was a simple dissipation problem, rather than "electric field". An inner coil of cable can only get rid of heat by being hotter than outer coils - which is a problem when those coils also are being heated by the same current. Effectively, the only parts of the cable that can lose heat to the environment is the exposed surfaces of the outermost coils and then only by radiation and convection. A rather smaller surface area than just those coils, unwound, would have - but it has to get rid of the heat generated by the whole length of the cable..

[malc]

Like Sue said, it's not an electric field causing the heating it's simply the resistance (or impendance if you want to be pedantic) of the cable. Because it was on the reel it couldn't dissipate the heat an so got hotterer and hotterer. Yes, because it was coiled there would be a slight inductance but I think at that frequency and with that coil diameter it would be so slight as to be negligible.

[fred]

If you really want to be pedantic it is definitely only resistance that results in heat, reactive components do not dissipate energy. Taking it a step further, the inductance will be bugger all as the flux from the live conductor will be cancelled by the flux from the neutral conductor.

[Vskødäjéllÿ]

Vshurrpyouj :-)

[Vskødäjéllÿ]

?id=15712&p=x4&cm_re=CROSS_SELL-_-SLOT1-_-15712&catId=PRODUCT_DETAILS&ts=33507&destination=/app/sfd/cat/pro.jsp%3Fid%3D15712%26p%3Dx4#>>

Just making sure it was comparable. Someone kicked it. It wasn't his. Someone had to replace it :-P

[Vskødäjéllÿ]

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Crikey! You need a thermal cut out button, like this one has :-)

[Farmer Giles]

Well it's been quite a while since I covered inductive reactance at college - 2 pi F L - but it was definitely measured in ohms in those days ;>). The inductive reactance at 50 Hertz is unlikely to be great but it would certainly add to the overall impedance of the cable and to the heat dissipated.

Taking it a step

I don't think that's correct. I think you are confusing this with the actions of a 'twisted pair'.

[Palindrome]

'Fraid not. The normal thermal cutout on a cable reel merely senses the current being drawn and not the temperature of the cable. It won't trip just because the cable has started to melt because it hasn't been unwound...

[Palindrome]

Maybe it has been a while too long.. But heat dissipated is watts and watts is I2R.

Again, a bit long away from the theory, I suspect. Twisting the wires is for an entirely different reason - it is the close proximity of the two wires that greatly reduces the electric field that is produced.

[Peter Andrews]

...but then it can't be described as a thermal cutout, it's a current limiter!

Peter

[fred]

You are wrong, inductive reactance is a lossless opposition to current

Wrong again I'm afraid, the flux cancels as I have described, no flux so no inductance and no opposition to current.

[fred]

In article , fred writes

That sounded a bit harsh, please substitute: "I think you'll find you are mistaken,"

[malc]

Yes, you're absolutely right, reactive components of impedance don't dissipate heat. I did think of the neutral cancelling out the live before I posted then carefully forgot all about it when I did post.

[fred]

I think I could have explained more/better in responding to FG, I think there is a slight confusion (among some) that ohms = heat without realising that ohms can come from lossy (resistive) or lossless (reactive) sources.

[Farmer Giles]

Doesn't matter how you say it, Fred, if I'm wrong I'm wrong. As I said it's been many years since I covered that kind of stuff - and, as I largely dealt with micro-electronic circuitry in my 40 years in the industry, AC power calculations were never a major part of my concern. The whole business of reactive power, apparent power and true power is a bit of a minefield - and one that I'd rather not have to think about these days!

Having said that, your statement 'no flux so no inductance' sounds incorrect to me - although once again being mindful of my rustiness in this area. Inductance is an inherent part of a material or circuit, that won't change with the signal or voltage applied to it - although its effects will of course. For example, a 10mH coil is a 10mH coil whether it has a 1mHz signal across it or a DC voltage. It will, of course, offer a high impedance to the 1mHz signal and only a low resistance to the DC - but it will still have an inductance of 10mH in both cases.