Hey guysA 6mm power cable can hold up to 25A, but, if a product draws a maximum of 4A, in theory, can this 6mm be reduced? If so, by approx how much?Cheers, much appreciated!! :)
Your wire has to be matched to the circuit breaker. If you have a 15 amp breaker you need #14 wire. Otherwise you could overload the wire and burn it out and the CB wouldn't blow.
yes. Resistance, and therefore voltage drop, is inversely proportional to the square of the radius or diameter. in other words, cut the diameter in half to 3 mm, the current capability would be 1/4 or 6 amps. 25/4 = 6.25, and square root of that is 2.5, and 6mm/2.5 = 2.4 mm, using only voltage drop considerations. If temperature in the wire is important, it gets more complicated, as you have to consider physical size of the wire, insulation type and thickness, etc. Of course wiring codes would override all this.
