variac / iso transformer conversion to 1-phase supply?

[Sansteeth]

Hello there,
I just found on the Internet a great looking, vintage Philips electronic workbench, that has a built-in variac, isolation transformer and something like 15 power sockets, isolated, grounded and ungrounded. I live not too far from the old Philips factories and my guess is that this type of equipment was sold in the region when Philips upgraded or moved the engineering facilities some place else.
I can have the bench for a great price but I was warned that it is supposed to be fed by a 3-phase power supply but that it could possibly be modified to be fed with a 1-phase power supply.
I tried to find information on the Internet but people are mostly talking about motors, ovens and other industrial appliances to be converted to 1-phase, which in that case looks quite tricky to modify.
But this workbench is really just an isolation transformer, a variac and a giant power strip to which I'm going to hook up tube amps, my guess is that the work bench does not inherently need 3 phase supply to operate.
Is it just the case of rewiring the power cable and leaving a bunch of wires out (safely)?
Or do the isolation transformer and variac special in a way that they are designed for 3 phase and cannot be converted to 1 phase without heavy modification?

What do you folks think?

[sluckey]

Draw out a schematic so we can talk about it.

[Sansteeth]

Sorry, I really wasn't clear in my first post, I don't have the bench in my possession. It's around 50 miles away from where I live and is sold for around $200.
I don't have the schematic, all I know is that the bench is meant for 3 phase.
I was asking in case it is a straight forward answer, but if you are asking for a schematic then I guess the answer is the dreaded "it depends" 
I cant really take the gamble, buy it and look into it because if an easy conversion is not doable, I end up having to re-do the whole electrical installation, buy a new variac, etc.. and that starts to make a very expensive bench ah

[sluckey]

I suggest you pass.

[Sansteeth]

I reckon you're right.... 

[PRR]

It is "possible" this is a simple connection. See attached. A 3-ph variac with all the frills. Just connect to one phase. In this case, there is a control system fed only by one phase so you need to feed that one or you can't turn it on.

However it is also possible you spend 50 miles and $200 and come up with some clever Philips engineering which won't work by just ignoring 2/3rd of it.

In the general case there is "always" a 1-ph connection BUT the way 3-phase works it "can" come out to be an odd diagonal (1.7X) voltage. Like our 3-ph school had 117V on one phase but 203V phase to phase. Which was slow-burning a 230V chiller in the lab. After 20 years they finally thought it through, but instead moved the lab across town.

EDIT: My error in drawing, top left, don't do this.

[shooter]

 

clever Philips engineering

I made a living fixing Philips cleverness
they do make good stuff, and they do like odd volts.
their 3ph main was something 340 - 360-ish range, we needed to provide a 480vac to Philips step-down

[Sansteeth]

However it is also possible you spend 50 miles and $200 and come up with some clever Philips engineering which won't work by just ignoring 2/3rd of it.

Yes, I've made enough costly mistake taking on tasks that I was not up to. It's a nice workbench, I would have bought it if it was wired for 1-phase power supply, but that and the fact I might be moving out in the next year, this big workbench doesn't look like such a good deal anymore. Nothing a couple of power strips and a stand-alone variac cant fix!

Thanks folks for chipping in!