It would be OK but you'd better put the 2 240 lugs in parallel on each side.

This is needed for having the maximum available power.

a écrit :
I was looking at the commercial isolation transformers and they are very
costly, so I decided to build my own. After all, all they are is a
transformer with a power cord on the primary and an outlet (and fuse) on
the secondary. And I already have an enclosure to put it in.

I'm looking at a bare transformer to use as an 120v isolation
Transformer. (120v in, 120v out). The transformer primary is 480 / 240.
The secondary is 240 / 120.

This is for single phase 60 cycle AC. (U.S. power).

Will it work if I connect the 240 lugs on the primary to 120 volts, and
use the 240 lugs on the secondary to obtain 120 volts.
Electrically, this makes sense, but I am not 100% sure, so I thought I'd
ask.

Also, this Transformer is rated at 750 va.

Using the calculator chart on
http://www.rapidtables.com/calc/elec...calculator.htm
750 va should give me 6.25 A output. (Which should be enough amperage
for anything I need to test on my bench).

However, since this transformer was intended to be used at 240 / 480 on
the primary, will it still give me 750 va (6.25 A) on the secondary if I
run it on 120v?

Thanks