[quickthrowman]

You can break the tabs on a 15A or 20A duplex receptacle to have (2) single 15A or 20A dedicated circuits on a single duplex receptacle.

It would require an additional run of 14/2G romex (12/2G for 20A) and a single-pole breaker, but allows you to skip cutting in an old work box to add a 2nd duplex receptacle.

You could possibly replace the existing 14/2G with 14/4G which has enough conductors for both circuits.

[jmalicki]

If you are going to do that, why not install a NEMA 5-20R receptacle, that has two independent circuits and is backwards compatible, as well as being rated for 20A per plug?

The receptacle is the easy part, running the new circuit is the hard part.

Or you know, install a new 240V receptacle.

If I have to:

1) Run wire

2) Get a bigger breaker box

3) To do it legally, hire an electrician and maybe get a permit

Replacing the receptacle is like, <1% of what's involved there.

[quickthrowman]

Breaking the tabs on the existing receptacle prevents one from having to use a jab saw or multitool to cut a hole in the gypsum wallboard or plaster and install a cut-in/old work box to add a 2’d duplex receptacle: https://www.homedepot.com/c/ah/how-to-install-remodeling-box...

Any 15A or 20A duplex receptacle can have the tabs broken to get two separate 15A or 20A simplex receptacles, you don’t need a 5-20R for that, a 3-wire 5-15R works just fine.

Someone upthread mentioned 1.2kW load which a 15A receptacle handles just fine: .8*120*15=1,440W continuous. Bumping that up to 20A only gets you an additional 480W of continuous load: .8*120*20=1,920W. A continuous load is one that runs for 2 hours or longer, the overcurrent protection and wire must be upsized by 1.25x (or derated to 80%)

Most receptacles in homes are wired with 14/2 romex which is only good to 15A (in homes, which use the 60C ampacity column) which is why I suggested pulling another run of 14/2G romex and breaking the tabs. Pulling 14/2 romex to an existing receptacle usually isn’t that hard if you have a fish tape.

AFAIK computer PSUs can’t easily use 240V power without a PDU in the middle, but I’m likely wrong on that, especially for server PSUs.

[jmalicki]

Almost all computer PSUs I have ever seen are 110/220 since they don't make different models for Europe.

[quickthrowman]

Gotcha, that would make sense. In that case, your suggestion of a 240V outlet is best. Swap the outlet for a 240V one, swap the breaker out for an 240V 2-pole, and use the same wire, assuming the wire is already big enough since you won’t need a neutral.