If you actually use two 120V circuits that way and one breaker flips the other half will send 120V through the load back into the other circuit. So while that circuit's breaker is flipped it is still live. Very bad. Much better to use a 240V breaker that picks up two rails in the panel.

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HWR_14 6 hours ago | parent | next [-]

They make connected circuit breakers for this use case, where one tripping automatically trips both.

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amluto 12 hours ago | parent | prev | next [-]

I assume the device has two separate PSUs, each of which accepts 120-240V, and neither of which will backfeed its supply.

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ycui1986 14 hours ago | parent | prev [-]

i am guessing, without any proof, that, when one breaker fails the server lose it all, or loose two GPUs, depending on whether one connected to the cpu side failed.

	▲	fc417fc802 13 hours ago \| parent [-]
		GPUs aren't electrically isolated from the motherboard though. An entire computer is a single unified power domain. The only place where there's isolation is stuff like USB ports to avoid dangerous ground loop currents. That said I believe the PSU itself provides full isolation and won't backfeed so using two on separate circuits should (maybe?) be safe. Although if one circuit tripped the other PSU would immediately be way over capacity. Hopefully that doesn't cause an extended brownout before the second one disables itself.