Buck boost transformer sizing

Hello,

I have two applications needing transformers to buck 240V to 208V.
Lately our supplied voltage is 238V and I use a rotary converter with balancing to provide 3 phase.

One load is a 200V air compressor I got help with here https://www.practicalmachinist.com/...-running-240v-air-compressor-troubles-302230/
11.6 full load amps at 200V.
A pair of 0.75 KVA Acme T181059 transformers have been working fine. Wired like so with the manufactured or fake leg as line 2 passing through the middle.
Could I have used 0.5 KVA transformers?

New load is a 3 phase ultrasonic cleaner at 200-208 V and 3910 W
After using some online buck boost transformer calculators and looking in the Acme catalog I decided on two at 0.5 KVA. Acme T181058

Then I receive the wiring diagram from the manufacturer and learn the three legs have unbalanced loads (probably the single heater element skews things)
L1 5.2A
L2 17A
L3 13.8A

In the meantime I've tested the cleaner using the ~200V from the 0.75 KVA transformers on the air compressor and it works well and voltages are stable without any or much drop between loaded and unloaded (Have not run both at once, don't intend to)

In hindsight should I have ordered 0.75 KVA transformers for the ultrasonic cleaner?
Can I use 0.5 KVA on the compressor? Which would free the 0.75 for the ultrasonic cleaner.
Or leave the compressor alone and are 0.5 KVA transformers OK for the cleaner?

I'm not electrically savvy enough to be confident in my calculations and the results of the various calculators I've tried.

Finally I would assume the two higher amp legs of the ultrasonic cleaner should be the real legs from the phase converter but what about their position in the transformer arrangement? Seems you'd want highest amp leg passing through the middle but you also want the fake leg in the middle and can't have both unless the fake leg from converter is one of the higher amp legs on the load...

Thanks,
Grigg

as long as the current flowing through the 24v winding is less than 30 amps you are not exceeding the rating of the 750va transformer. or for a 32v transformer, 23 amps.

as for the ultrasonic cleaner, you might be able to run it on 240v. check with the manufacturer. the heating element won't care. you could even wire the heating element for 240v and use a pair of 200 watt 32v transformers for the buck boost.

the amp draw suggests it might even be single phase, requiring only a single, 5 amp rated 32v transformer for the driver and a 13 amp circuit for the heater (thought the amps don't quite suggest it is that simple, but amp clamp meters are often wrong)

anyhow wire it as suggested in the other thread.

Thanks for the ideas.

I've already contacted the manufacturer about reconfiguring it for single phase or 240V and it's not possible/feasible. I looked inside and agree it's not straightforward.

The amp figures are from the wiring diagram they provided, not measured.