PDA

View Full Version : 240V VFD to power 110V motor



m_c
30-10-2021, 11:17 PM
Since nobody seems to want to buy my old lathe due to it's current dual voltage setup, I'm thinking about changing it so it runs solely of 240V.

The spindle is easy enough to sort, but the turret is more of a problem.
It uses a 600W 3 phase 110V motor, which is currently powered via a 3 phase 415->110V transformer, then two interlocked contactors for forward/reverse.

If I was to power it with a VFD, am I correct in thinking, all I need to do is change the rated motor voltage setting in the VFD from 230V, to 110V?

Chaz
31-10-2021, 09:41 AM
Not sure about that. In my experience (limited), the VFD's voltage output is pretty much set. For example in my 9100 VFD, they offer some tuning of the output but its like 380-410, not anything that would allow me to half the voltage.

That said, why not try one, set it down 110V and use a dummy load and measure what it outputs.

Kitwn
01-11-2021, 08:35 AM
Are you sure that's the reason it isn't selling? The way I see it, you are proposing to spend money to replace a perfectly acceptable and well understood method of powering the 110V motor with something which is probably less reliable, more complex and difficult to replace or fault-find at a later date.

Kit

m_c
01-11-2021, 10:25 PM
Not sure about that. In my experience (limited), the VFD's voltage output is pretty much set. For example in my 9100 VFD, they offer some tuning of the output but its like 380-410, not anything that would allow me to half the voltage.

That said, why not try one, set it down 110V and use a dummy load and measure what it outputs.

VFDs vary voltage according to frequency, so at below motor rated speed, they're reducing voltage anyway, it's just that I'm not sure it'll be as simple as changing a single parameter.
If I had a standard VFD surplus, I would try it and see, but I've not just now.

m_c
01-11-2021, 10:31 PM
Are you sure that's the reason it isn't selling? The way I see it, you are proposing to spend money to replace a perfectly acceptable and well understood method of powering the 110V motor with something which is probably less reliable, more complex and difficult to replace or fault-find at a later date.


I've had a couple people interested, but they've not had access to 3 phase, which is why I'm thinking about changing it.
Currently it needs 3 phase for the spindle and turret, and single phase for the controller and servos.

I am considering keeping it, as it can do things it's replacement can't, but I would like to simplify how it's powered regardless.

Kitwn
02-11-2021, 03:51 AM
I've had a couple people interested, but they've not had access to 3 phase, which is why I'm thinking about changing it.
Currently it needs 3 phase for the spindle and turret, and single phase for the controller and servos.

I am considering keeping it, as it can do things it's replacement can't, but I would like to simplify how it's powered regardless.

For some reason I failed to notice that this is a 3-phase motor even though you wrote that twice! Must press the 'ON' button on my brain before writing comments in future!

Kit