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by saltminer 535 days ago
You can't use a NEMA 14-30 to power a PC because 14-30 outlets are split-phase (that's why they have 4 prongs - 2 hot legs, shared neutral, shared ground). To my knowledge, the closest you'll get to split-phase in computing is connecting the redundant PSU in a server to a separate phase or a DC distribution system connected to a multi-phase rectifier, but those are both relegated to the datacenter.

You could get an electrician to install a different outlet like a NEMA 6-20 (I actually know someone who did this) or a European outlet, but it's not as simple as installing more appliance circuits, and you'll be paying extra for power cables either way.

If you have a spare 14-30 and don't want to pay an electrician, you could DIY a single-phase 240v circuit with another center tap transformer, though I wouldn't be brave enough to even attempt this, much less connect a $2k GPU to it.

2 comments

As far as I’m aware (and as shown by a limited amount of testing that I’ve done myself), any modern PC PSU (with active PFC) is totally fine running on split-phase power: you just use both hots, giving you 240v across them, and the ground. The neutral line is unnecessary.
If you installed a European outlet in a US home then it would be using the same split phase configuration that a NEMA 14-30 does. But many appliances will work just fine, so long as they can handle 60 Hz and don't actually require a distinct neutral and ground for safety reasons. Likewise NEMA 10-30, the predecessor to NEMA 14-30 which is still found in older homes, does not have a ground pin.
I thought the main purpose of providing the neutral line was to be able to power mixed 240V and 120V loads.