Did a job breathing life into an old hydraulic brake,or bender to the non metal fabricating crowd, as side job.
It was wired 480 3 phase and we were running on a generator. When discussing wiring it for 230v the lack of
3 phase service created a problem. 3 hp single phase motors cost too much and draw too much power.
The old world fix would be rotary converter or using capacitors to create a fake third phase.
But with the rise of hefty diodes and circuitry to make variable frequency drives to change 3 phase motor speeds a new choice
has been created.
This is possible because they take the AC input, rectify it, create sinewaves that the frequency can be altered electronically.
They can do it just as easily with a single input. A drive capable of running a 3 hp 3 phase motor for under $400.00 in a dirt and oil
sealed case rated NEMA 4. With most Bridgeport millers and most clones run 1 1/2 hp motors the cost is slightly less.
The motor I was driving was 3hp which at full load draws 10 amps. When running it peaked around 8 amps when the ram started to move.
A single phase motor that size would be drawing around 17 amps and dims the lights on start up.
Just fueling the creative juices, and the question, your buying a what?
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