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15x30 leblond vfd help 1963 servol shift

Kruzzz

Plastic
Joined
Dec 20, 2021
I have just purchased a 1963 15X30 lablonde lathe servol shift need to wire up in my garage. don't want to get too fancy I want it to work like it did in 1963. can I hook up VFD to my 1ph 220 and then 3ph 240 out to my shut off box on lathe and use it like it was used in 1963.I will set vfd to 60 hz and leave it there. Lathe is currently wire for 3ph 240.
 
A VFD won't work that way.

Your best bet is a rotary phase converter. Many threads here on how to build and/or install one.
 
A VFD won't work that way.

Actually they can.

I have a 10 hp Teco box, modified by Drives Direct to voltage double 220 in to 440 out, sitting on my shop wall thats been doing that for over 10 years. Basically low rent substitute for real utility power.

But

Running like that needs considerable de-rating to cover the start-up surge load without the box faulting out. Drives direct say 50% de-rate so maximum motor size would be 5 hp. Probably OK if the motor spins up off load but 3 hp is as large a single motor that I'm happy to start. It will drive 10 hp worth of motor just fine. Start-surge is the issue. I have smoothing chokes on the output which help too.

Primary reason that VFD type boxes are not supplied to operate as fixed frequency "utility substitute" devices is that you need to buy a device about 3 times larger than what the motor needs to handle start up and surge. So 3 or 4 times the cost for little benefit. From a manufacturers point of view such boxes would have severely limited applications and some tricky installation issues in general use.

Clive
 
No problem buying upsized VFD I can put 10HP on it will it run 1/2 hydraulic pump servo motor and coolant Pump I think it run 110v.
 
My understanding is that using a VFD as a 3 phase power source doesn't always work well for transformers, contactors and other electrics running off a VFD and it needs to be substantially derated if it is going to handle the start-up serge of the motor. Also the degree of derating depends on the VFD, as many of them these days are derated much more for running off of single phase and normal/heavy duty in constant torque mode. They need to be run in a fixed V/Hz mode. You can direct connect the VFD to the motor and use the VFD low level inputs to run the primary lathe motor. Coolant is usually 3 phase, so may also need to be switched out if you plan to use it. An RPC is a better option if you want a plug and play option, you can buy a control box and pick up an idler motor locally for a lot less than getting/installing an oversized VFD.
 








 
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