Thinner Low Amp Ehu Cable? (1 Viewer)

[makems]

BUT !!!!
Like everything in life the above is little more than the opinions and findings of various folk..
And we all know about opinions don't we LOL !!!

You are probably referring to the fact the opinions are like arseholes - everybody's got one!

 

[Jaws]

Yes.. but I was being a little more subtle LOL !!!

 

[makems]

As for real life experience of the effect of coiled cables:
Last year before setting off for our Morocco trip I had the van hooked up to a socket in the garage. Gwen wanted to put some washing in the tumble drier (also situated in the garage) so I used one of those 30m reels with 4 power sockets on it (you know, the sort that many French MH era use as an EHU cable). I plugged both the van and the tumble drier in without uncoiling the cable.
15 minutes later I went back in the garage and could smell something "hot" and started looking around. When I checked the cable reel it was absolutely red hot, too hot to touch in fact and I had to get a pair of gardening gloves so that I could unreel it all.
So, coiled cables DO get hot, very hot.
I dare say that there are quite a few factors involved such as how tight the coils are, how thick the cable is, what current is being carried etc etc.
After this experience I won't be leaving my EHU cable tightLy coiled again. (Or plugging appliances that use a lot of power into a cable reel)

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[Sidney]

Excellent video, see so many idiots wrapping the cable around their arms, I used to do sound engineering for bands.

idiots? A little strong?

 

[Jaws]

Not really.. There is enough warnings about it and the consequences of doing it that anyone not heeding them is perhaps a bit soppy ?

if you parked up next to a van in a European site and there was a fire caused by such a thing, I suspect you your self might be calling the folk who destroyed you van something a little stronger !!

 

[Lenny HB]

idiots? A little strong?

Not really it wrecks the cable.

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[JJ]

I don't carry a tumble dryer in my motorhome.

JJ

 

[Sidney]

I don't carry a tumble dryer in my motorhome.

JJ

Perhaps some think if you pay for a 16amp connection you should use all of it?

I have a couple of thinner EHU in artic blue. On most European sites the MCB would trip before there was any issue.

At Le Mans 24Hrs these must have had 25 Amps going through them with every man and his kettle hooked into the same cable via an assortment of extensions. I also roll them up anyoldhow without loosing any sleep.

But I am a rebel (who only uses a 16amp flex when I need it)

 

[Old Soldier]

Not really it wrecks the cable.

I have used the same cable for over 10 years and most times I wrap it round my elbow. Still working and not wrecked yet...... Can't work out what the problem is, only rolls it up the same as if on a drum or one of those cable carriers. Having said that, I will try out the over and under method just to see if it works for me. Prepared to change if advised, not like a few on here...

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[Jaws]

Right.. Done the experiment as I said earlier..
VERY interesting results and you can actually see on the scope what is happening

While some of the coils happened to be in phase with one and other, where ever they were out of phase by more than approx 30% you could see pretty large spikes of current being formed.. ( obviously you cannot see the current .. I could only see the voltage drop but it was pretty easy to work out what current was being drawn as I knew the load ) Now then.. That means the problem IS induction induced and not because of thermal conductivity !
But what is really interesting is that when you think on this further it should not be possible for the current to vary along the length of the cable,, It SHOULD remain a constant.. Which means ( to my mind ) the issue is actually worse than we all first thought as some parts of the cable will get hotter than others

And another interesting thing. In theory the wavelength at 50 cycles is 6000000 metres !!! **
So there must be some VERY serious harmonics going on to say the least to get the variations in the phasing over such a short length

The test was set up at 50 cycles using a length of standard hook up wire about 15 metres long ( it was left over after some berk on a CC site ran it over with a ride on lawn mower !!!!!! ) I wound the load up to a maximum of 10 amps to get the results.. I saw no point in increasing the load as the effect would not change, merely the level

** where wavelength = 300/f in mhz = 300 / 50 or 300 / .000005 !!

1,000,000 Hertz = 1000 Kilohertz = 1 Megahertz

 

[Old Soldier]

Right.. Done the experiment as I said earlier..
VERY interesting results and you can actually see on the scope what is happening

While some of the coils happened to be in phase with one and other, where ever they were out of phase by more than approx 30% you could see pretty large spikes of current being formed.. ( obviously you cannot see the current .. I could only see the voltage drop but it was pretty easy to work out what current was being drawn as I knew the load ) Now then.. That means the problem IS induction induced and not because of thermal conductivity !
But what is really interesting is that when you think on this further it should not be possible for the current to vary along the length of the cable,, It SHOULD remain a constant.. Which means ( to my mind ) the issue is actually worse than we all first thought as some parts of the cable will get hotter than others

And another interesting thing. In theory the wavelength at 50 cycles is 6000000 metres !!! **
So there must be some VERY serious harmonics going on to say the least to get the variations in the phasing over such a short length

The test was set up at 50 cycles using a length of standard hook up wire about 15 metres long ( it was left over after some berk on a CC site ran it over with a ride on lawn mower !!!!!! ) I wound the load up to a maximum of 10 amps to get the results.. I saw no point in increasing the load as the effect would not change, merely the level

** where wavelength = 300/f in mhz = 300 / 50 or 300 / .000005 !!

1,000,000 Hertz = 1000 Kilohertz = 1 Megahertz

Thanks Jaws......For plonkers like me......what's that mean in simple English?

 

[Jaws]

Absolute basics.. Do not use a coiled up EHU lead !! Now proven scientifically rather than just an educated guess

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[Old Soldier]

Absolute basics.. Do not use a coiled up EHU lead !! Now proven scientifically rather than just an educated guess

Not a plonker then after all.....! Thanks for backing me up....

 

[Gizmouk]

Absolute basics.. Do not use a coiled up EHU lead !! Now proven scientifically rather than just an educated guess

As "supported" by the derating tables in the electrical regs book