hi sporket wondering if you could enlight me on this one iwas told it was dangerous if the excess cable on my electric hook up tidy was still rolled up could cause the cable inside cable tidy could cause a fire whist plugged in thanks dave
eletric hook up cable
- Thread starter david_374531985
- Start date
David that's correct you should unroll it and spread it about tiredly on the ground, the heat generated whilst rolled up can cause it to melt and set a fire, it's the same with any extension roll, if you read the instructions it tells you to unwind off the roll before use.
NigelH
NigelH
David,
Always uncoil the electrical extension cables fully, as these can overheat and cause a fire.
Use an extension lead of appropriate length, but always fully uncoil the lead before use.
Have a read of this
C & CC policy for electric hook -ups on club sites
Always uncoil the electrical extension cables fully, as these can overheat and cause a fire.
Use an extension lead of appropriate length, but always fully uncoil the lead before use.
Have a read of this
C & CC policy for electric hook -ups on club sites
good morning sprocket thanks for your reply just wanted to prove a point to an electrician who disagrees with the danger that wound up hook up cable can cause this chap was in next pitch to us when we had this discussion will keep my eye open for him when season starts regards dave
Overheating will only be an issue if you have lots of current running through the cable ie high usage.
Summer use(no electric fire) ok.If you read on most extension leads they give 2 readings one for unwound and one for wound.
You judge by what equipment you are using as uncoiled cable becomes a trip hazard.
Summer use(no electric fire) ok.If you read on most extension leads they give 2 readings one for unwound and one for wound.
You judge by what equipment you are using as uncoiled cable becomes a trip hazard.
I was told a story by a telephone engineer, that many many years ago, before health and safety was invented, he connected a roll of copper cable, with the last metre or so stripped, to his wee portable hand generator thingy, that was used to put a small current down the line for testing,and asked "the gullable apprentice" to hold on "until it was tested", not thinking he turned the handle to wind it up to send a small current down the cable, but because it was coiled the current increased by quite a lot, and nearly knocked the young lads melt in, although it could have been quite serious, apparently, it was hilarious!!!
It is the electro magnetic induction that causes the heat build up in the coiled cable.The same thing happens in any copper coil with power running through it.
I can certainly vouch for the effect on extension reels.
I had (had being the key word here!) quite a long 13 Amp extension cable on a roll up drum and failed to totally unwind it one time whilst using a floor cleaner that was drawing around 10 amps. I think it was a 20 or 25 metre extension, probably with half the cable left wound on the drum.
After about 15 minutes the cleaner stopped and on further investigation, the inner most windings on the drum had melted right through causing a short circuit which blew the fuse in the extension lead plug.
Fortunately there was no fire from the drum and the fuse blew before things got any hotter. Lesson learned!!!
Even though our hook up cable is loosely coiled when stored in a carry bag and is not wrapped on a former, I always spread it out under the caravan to be absolutely sure.
As Mikey says though, it is all to do with the current draw.
I had (had being the key word here!) quite a long 13 Amp extension cable on a roll up drum and failed to totally unwind it one time whilst using a floor cleaner that was drawing around 10 amps. I think it was a 20 or 25 metre extension, probably with half the cable left wound on the drum.
After about 15 minutes the cleaner stopped and on further investigation, the inner most windings on the drum had melted right through causing a short circuit which blew the fuse in the extension lead plug.
Fortunately there was no fire from the drum and the fuse blew before things got any hotter. Lesson learned!!!
Even though our hook up cable is loosely coiled when stored in a carry bag and is not wrapped on a former, I always spread it out under the caravan to be absolutely sure.
As Mikey says though, it is all to do with the current draw.
I agree, In my experience of this you'll melt the cable sheathing and cause a short. this will pop the fuse. I think causing a fire is unlikely.
Is this one for 'Myth Busters'?
Is this one for 'Myth Busters'?
i also had this with electricalman and said this is the old days you talk about new cable dosenot do this ther use to be a problem with over heat .
- Mar 14, 2005
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There are three factors involved here - resistance and , induction heating and thermal insulation.
The primary one is the amount of current being used. All cables have some resistance to current flow and they will self heat in proportion to the current. The insulation will tend to prevent heat loss, so a temperature rise of a few degrees in the conductors is not uncommon.
with the cable fully unwound the surface area of the cable exposed to free air allows for the heat to dissipate easily, but if it is tightly packed on a reel, the inner coils cannot cool so effectively and substantial heat build up can occur.
In addition, any wire that is coiled up with a current passing through it will produce a magnetic field, which is an induction loop. When and inductor is subjected to an alternating current (mains is 50 cycles) the inductor needs energy to keep swapping the polarity of the magnetic field. This also causes conductor heating.
The combined effects of resistive and conduction heating can build up considerable temperatures in the cable drum - enough to melt the PVC insulation, and may be sufficient to ignite nearby flammable materials.
Anthony(ni)
The effect you write about is not an increase in current, but the storage of electrical energy in an inductor (coil). as described above if you pas a current through a coil, it produces a magnetic field in and around the coil.
When the current is turned off or disconnected, the magnetic field collapses and this has the reverse effect of producing a current in the coil. Each loop of the coil will generate a small voltage, but voltage is multiplied by the number of loops, so you can build up a substantial voltage which will give you shock. Note it is the voltage not the current that is made bigger.
The primary one is the amount of current being used. All cables have some resistance to current flow and they will self heat in proportion to the current. The insulation will tend to prevent heat loss, so a temperature rise of a few degrees in the conductors is not uncommon.
with the cable fully unwound the surface area of the cable exposed to free air allows for the heat to dissipate easily, but if it is tightly packed on a reel, the inner coils cannot cool so effectively and substantial heat build up can occur.
In addition, any wire that is coiled up with a current passing through it will produce a magnetic field, which is an induction loop. When and inductor is subjected to an alternating current (mains is 50 cycles) the inductor needs energy to keep swapping the polarity of the magnetic field. This also causes conductor heating.
The combined effects of resistive and conduction heating can build up considerable temperatures in the cable drum - enough to melt the PVC insulation, and may be sufficient to ignite nearby flammable materials.
Anthony(ni)
The effect you write about is not an increase in current, but the storage of electrical energy in an inductor (coil). as described above if you pas a current through a coil, it produces a magnetic field in and around the coil.
When the current is turned off or disconnected, the magnetic field collapses and this has the reverse effect of producing a current in the coil. Each loop of the coil will generate a small voltage, but voltage is multiplied by the number of loops, so you can build up a substantial voltage which will give you shock. Note it is the voltage not the current that is made bigger.
If you look at any decent reel type extension cable you should find wriiten on the reel itself the different current ratings in use.
e.g. much lower rating fully wound than unwound.
It's really not hard work though to unwind the cable spread it out and be on the safe side.
Tom
e.g. much lower rating fully wound than unwound.
It's really not hard work though to unwind the cable spread it out and be on the safe side.
Tom
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