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415v three phase from 240v single phase a home made digital phase converter?
I don't have three phase at my place and getting it would be expensive. With that in mind I set up an experiment that has been a few months in the making (I had to wait for Kryn to bring me a crucial part from Melbourne). The picture shows a 240V VFD (only 1.5kw here) connected to an 8Kva three phase autotransformer.
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The autotransformer was originally designed to take three phase 415v and output 230v three phase but I run it in reverse. Setting the VFD to ramp up to 50hz at 240v over a few seconds avoids an over current situation when switching the thing on . I connected my unmodified Colchester Bantam to the output of the transformer and was happy to see it run with direct online starting without any issues. As expected the inductance of the transformer avoids any over current situation at the VFD when the motor starts.
As mentioned this was using only a 1.5kw VFD I intend getting something around the 4kw mark so as to more fully utilise the capacity of the transformer any suggestions here would be welcome.
The voltage out of the transformer even in reverse is around 400v so close enough.
Anybody see any problems using this as a phase converter?