Hi buddy,
that thing is for a caravan or motor home (Recreational vehicle).
Basically it allows you to run your RV (or some relatives RV) off your home powersupply.
similar to things you have in a campsite etc.
So:
Option a: without calling a sparky in, you could get the electrics from an RV from a junkyard, and drag that home - then plug it in and run all off your stuff off that power source.
This is a bad choice
Alternatively, you COULD run it off an australian/new zealand 3112 plug.
https://en.wikipedia.org/wiki/AS_3112Thats what we have over here.
One variant will handle 32amps. Pop that through an australian UPS that handles 15-32 amps and then run that into a 240v power supply (unless it spits it out at 120v)
I'd do this as I have hi amp gear here but I'm in Australia and the UPS alread handles that amperage. Otherwise its a dumb idea
Optionally, get a transformer from somewhere in your country that drops the RV outlet into whtaever is standard for your country.
This is the safest option of these three - as if you can find a transformer that is designed to do the conversion, then thats the only safe way of doing it (without buying an RV).
However, if you don't plan on investing in a caravan - just get a sparky in and convert that 30amp plug into another phase or line that you can run not only your PCs off, but airconditioners and washing machines and high powered machining gear off, since that plug is probably in your garage.
(atleast over here, our standard output is 10 amps, with airconditioner ones at 15 amps).
So basically - buy a transformer, or get a sparky in to fix it.
30 amps is a fair whack at 120v AC. So do something with that plug - if you have kids and no RV, just get rid of the damned thing and get it replaced by a sparky.