A PC using an HX850 power supply (850W) had an original power cable rated 13A/125V but that cable is lost. (I know the original cable rating because I have other computers the exact same spec that aren't missing any original parts.) The power cable from this one PC has been lost and the only spare ones I can find are rated 10A/125V which appears to be much more common.

Is it safe to use a power cable with a lower amperage rating than the original? If not, what risks are there?

I imagine using a cable with lower amperage risks not providing the PC power supply sufficient wattage when it's needed. Not sure what symptoms that could translate into and how severe, but I figure much worse would be to use a higher amperage replacement cable, which could potentially send too much wattage to the power supply causing catastrophic symptoms like overheating and burning out parts.


The Corsair HX850 power supply has an input rating of 12A at 100V (1200W) and 6A at 240V (1440W). Note that this is different than the output wattage. A cable rated for 10A at 125V (1250W) is about the same.

The rating is used for safety, not a physical maximum. The cable will work fine even if you were using the maximum capacity of your power supply (which is unlikely). If you had a very diligent electrical inspector, they could argue that it's not correct.

  • And the power supply is 850W. So as long as the cable can supply as much as the power supply would try to draw, and the plugs fit fine, it's safe to use? – cr0 Oct 22 '18 at 20:24
  • @cr0 I changed my answer after realizing that the input rating needs to be used. Sorry for the confusion. – Jason Oct 22 '18 at 20:35
  • The update still makes sense to me, except I'm surprised there's an input rating at 100V, since I think of standard circuit voltages as either 120V or 240V. If it expects 12A 120V, then the cable cannot (safely) support the maximum input wattage the power supply may try to draw, but if the power supply only outputs 850W max it is probably a non-issue anyway. – cr0 Oct 22 '18 at 20:51
  • could you link me to where you found the 12A 100V input rating? I don't see any input rating on Corsair's specs page for this unit. – cr0 Oct 22 '18 at 20:52
  • 1
    @cr0 100V is used in countries such as Japan. You can find the input rating on the second page of this document: corsair.com/corsairmedia/sys_master/productcontent/… – Jason Oct 22 '18 at 21:03

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