Good or bad

[munnik]

I am looking at neatening up my tangle of heatpad and light cables. I would like to just roll up the cables (circular like a garden hose) and fasten with cable ties. Someone once told me it is bad to roll up a cable and then use it in it's rolled up state. Is this true.

The reason the cables are long is that the cages were once far from the wall socket. I don't want to cut them shorter as one day I might need the length again.

[Bundu Boy]

Buy some shorter cables bro,

even so, if you want to roll them up then that should be fine. I've used rolled up cable without any probs before...

[CLSmith]

Rolled-up electrical cable that receive a current, will heat up, as a electro-magnetic field builds up. Because heat pads and lights are on almost constantly, you will have a fire hazard around the coils. The wire and covering will become hard and brittle after a while.

Make the coils as long and few as possible. Maybe around hooks on the corners on the back off the cages.

Anyone with Electrical background may correct me here, but this is Safety 101. Do not use rolled up electrical cables.

[Snakes4Africa]

Tighly rolled cable is going to cause a problem!

[froot]

Wire wound in a coil of a number of turns becomes a reactive load. A coil has a certain amount of inductance which basically means that it momentarily stores some of the energy that passes through it. Inductances cause a dT phase shift between the voltage and current waveforms of a circuit. Weather this is a problem or not depends on a few factors:
1) If you're using a multicore cable such as flex or the sandard 3 core cable used for household appliances to power a load (conventionally from plug to load) you need not really worry about coiling it up, The returning current cancels the magnetic field generated by the current sent to the load. Think about it, if this was a problem then they wouldn't be selling those wind-up extensions right? That's just one big coil. If each leg of the circuit is wound into a coil independantly then proceed.
2) The amount of current flowing through the cable. This is determined by the device you are powering with the cable, if it's a heating pad that only draws a few milliamps then I wouldn't worry. If it's a high power device such as a element heater then effects generated by a coil in the circuit will be worth considering because of the amount of current flowing through it.
3) The amount of turns, wire thickness and dimensions of the coil. These all play a role in determining the inductance of a coil.
4) Is the coil wound around air or a conductive material? If it's a conductive material then the coil is inducing eddy currents in the conductive material around which it's wound. You'll find that this 'core' material heats up considerably. It's the basic concept that's used in inductive heating in industry to melt steel. Don't do that!

There is a larger risk of fire if you have your heating cable strands touching each other, they don't like that and the smoke could easily escape.

[munnik]

they don't like that and the smoke could easily escape.

Someone once told me the whole secret to owning a computer is too keep the smoke inside the tower and the monitor.

Thanks guys for shedding some light.

Andrew