Is it legal to use brown and blue for live and neutral wires in equipment sold in the USA, which uses 110v?

I was looking at a teardown of an ATX power supply and one of the photos (see below) showed that the mains inputs were brown and blue, even though the input is universal and could be 110v.

photo of mains input on ATX power supply

  • 4
    \$\begingroup\$ If you have to tear it down to even see it, no problem. External wiring is a different matter. \$\endgroup\$ – Brian Drummond Feb 21 '19 at 21:39
  • \$\begingroup\$ @BrianDrummond, short as it is, that is the answer -- you should copy it and paste it into the answer box. \$\endgroup\$ – TimWescott Feb 21 '19 at 22:06
  • \$\begingroup\$ Thanks for the answers guys. I can't imagine anywhere you'd see the individual phase colours outside of the box unless you stripped back a cable \$\endgroup\$ – coates Feb 21 '19 at 22:55
  • \$\begingroup\$ Hi guys I asked a similar question on Quora and got a disagreement of opinion. quora.com/…. Who's right in this case? \$\endgroup\$ – coates Feb 23 '19 at 16:34

ATX power supplies, as well as other switching power supplies have something like this on their designation label: "Do not remove the cover. Trained service personnel only. No user serviceable components inside" So, basically consumer should not remove the cover and care about what is inside.

Also they are designated to use in wide input voltage\frequency range, not just 110 VAC/60Hz, so it's up to customer where to use them (and different standards could be applied). They typically can work in wide input voltage range, from 100 up to 240 VAC (both 50 and 60 Hz) and sometimes even from 12 VDC, so you can use it in any country and with any input voltage and frequency, just by changing appropriate power supply cable (and plug).

Such supplies are mostly produced on big factories in China and are sold worldwide. So the manufacturer has only one schematics and one production line for all countries with the same wires colors.

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