Q:

Electrical Induction, what are the cable limits before it becomes a problem

I have a little hobby that has 3 power cables coming and going (each cable is 12V DC, 7.55 amp max).
Now these cables are ridiculously long (approx 5m+) and the equipment having to be mobile is small 0.5mx0.5x0.5.
Been looking at solutions to better cable management but nothing has stood out yet, most invovle having cables stretched out, which doesn't help me.
Now i am considering of creating 3 small spools that i can wrap each of the power cables on and then attach the spools to each other.
This is where i been advised to be careful of induction and to look into it.
Now considering the low power of these cables (the equipment is sensitive so doesn't consume large amounts of power) would my solution of creating 3 spools if power cables then attaching them together next to each other cause induction and thus problems or am I within safe limits to do this?

A:

Induction isn't the problem, even at 50Hz, and certainly not at DC, when winding a few metres of wire onto a spool. What IS a problem is heat : a wire in open air cools reasonably well, and the heat is spread out over its length. On a spool, the heat is concentrated and the inner turns of wire are insulated by the outer layers. Draw too much current - even though the wire is within its normal ratings - and ... well you don't want its insulation to melt.
If your equipment takes 7.5A, this may matter. If your wires are rated for 7.5A but the equipment takes a couple of amps or less, you'll be fine.

