I’m reasonably sure we can get 2HP out of the drive on single phase, and that a 10HP drive would be a better match to the motor specs if we’re trying to run on only one leg.
what I don’t know, is whether a 10HP 480V drive can be run 200V without pissing it off/derating it.
any suggestions for getting this fuge swinging at full speed on single phase would be appreciated.
not quite being sure how the magic is performed, I’m still unclear on feeding a VFD with a voltage below spec. seems like it should be kosher, but I’m a biologist, and electrickery is technically outside of my training
Edit: the link @thesk8nmidget posted clearly states that feeding a VFD the wrong voltage is not kosher. glad I asked. makes sourcing a replacement a hair more difficult.
Most VFD’s have a tolerance for input voltage outside of which they’ll error out and refuse to light up the outputs.
You can certainly use a suitably sized buck-boost transformer to get a 208-240V supply up to the 460-480V range so it won’t pitch a fit.
As far as running on single phase, depends entirely on the VFD. Some VFD’s require a 50% derate (so 10 HP VFD to drive a 5 HP motor on single phase), some are built to run on 1 or 3 phase, some are built to run on single phase only. Hell, on small motors you can even get 110V input drives that give 230V 3 ph outputs.
I wouldn’t call myself an expert on VFD’s but I’ve installed and commissioned a whole lot of them, including several on things like my lathe, mill and cold saw that are set up to run on single phase inputs because my former shop didn’t have 3 phase power piped in.
Yes. VFD’s are good for controlling motors, not great for powering control circuitry or other VFD’s without a lot of extra power conditioning between the two. They also really don’t like having their outputs disconnected while running.
For doing that you might look at something like a Phase Perfect, which is sadly going to cost a lot more than a large VFD will.
You need to drop freq and maintain volts and amps. You can’t use a basic drop out vfd. You need a unit that control only dropping out freq. Or else motor will draw too much heat and burn out.
Not only that; if its spinning at a lower RPM than what its speced out to be; the cooling fan wont be spinning at spec and wont extract as much heat as it should, it ends up being a vicious cycle that ends up reducing the service life tremendously
you need at least double what the motor is rated for, if you had 18 amps you would require 36 amps power, your drive data sheet says 23.8 amps if Im not mistaken. I wouldn’t attempt to run single phase, just generate a third phase or get it wired in from the pole, then step up or down with a buck boost transformer to meet the motors requirements. Do you need an explosion proof cabinet for the drive?
