I have some small woodworking machines with 440V motors and have been looking for a used 3KVA 3 phase transformer to step up the output of my rotary phase converter to 440V, no luck so far. Used single phase 220V/440V machine transformers are easier to find, so I was thinking about getting 3 identical 1KVA machine transformers and wiring them up as a 3 phase transformer instead. I did find some 15KVA 3 phase transformers for sale, but they are 5 times bigger than I need. I don't know how bad the losses would be from using a transformer that is so oversized. Maybe the loss wouldn't even matter. I only need to run 440V motors up to 3 hp for brief times. Thoughts?