mobeewan wrote:
It is a bad idea to leave a cord or cable coiled with power running through it. Especially when it may be running the max amount of amps the wire is rated to handle. It has a tendency to heat up because of the resistance created by the magnetic field generated by the coils. The same principle as winding a wire around a nail and sending a current through the wire to turn the nail into an electro magnet.
No, not really.
If the power cable is composed of both current carrying conductors (hot and neutral) than any magnetic field generated by the one is canceled by the other. The inherent inductance of the wire, and the inter-conductor capacitance will have a greater influence on the total impedance than any practical coiling of the whole cable.
Potentially, the loops of coil in the middle will have less air flow, so their ampacity (maximum safe current capacity) is less. That too would seem to be a minor factor.
Having the cable stuffed inside a small box with no air vents - now
that could cause a rise in temperature and thus a decrease in apmacity.
So - as I see it, the risk is from overheating the cable while it's in the storage box - not because it's coiled but because the box can get hot.
Me? I didn't like the rodent/insect access hole so I made mine detachable with a marine bulkhead connector mounted to an aluminum plate to cover the original hole.
