I've searched through the questions that have been asked but none have dealt with this particular problem:

I'm designing a PSU board that will have, among other things, a 12V/3A regulator. I want to transfer this 12V/3A regulator output to a separate motor driver board over a wire/connector.

Can anyone tell me what type of connector/wire I would need to transfer this 12V/3A? I've used an online wire gauge calculator which says that I need a 14 AWG wire for 12V/3A over a length of 0.1 feet, but the wholesaler websites that I've looked at do not specify the current rating/ampacity of the wire.

Cheers, Tony

  • \$\begingroup\$ Given it is the same material, ampacity should be the same for all wire sizes. \$\endgroup\$
    – PlasmaHH
    Commented Feb 14, 2017 at 13:35
  • \$\begingroup\$ "500 circular mils per Ampere" or simply, "4 Amperes per mm²". Quite acceptable for low voltages and short distances. \$\endgroup\$ Commented Feb 14, 2017 at 13:41

1 Answer 1


There are two factors that determine the wire thickness for an application these are:-

  1. Ampnicity. Is the wire thick enough not to catch fire when you put that much current through it. In this case you are ok.

  2. Voltage drop. This is a function of wire resistance and length. As you are only dealing with a few inches you are ok here as well.

The equivalence of other wires from different manufacturers has been covered by @PlasmaHH in his comment. If it has the same area of copper you are ok. You do have to take into account the quality of the insulation for ampnicity and this may be an issue with some foreign manufactured wire. However you are well inside the safe zone for this.


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