hotponyshoes
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- 6,450
- Location
- Somerset. Uk
Several years ago I moved out of a workshop with 3-phase so put a cold cut saw into storage and got a single-phase one to go in the current workshop.
I dug it out at the weekend as I thought I would have a go at running it from single-phase via a vfd now they seem to be available at cheap prices!
Anyway, I'm not sure quite how simple this will be... I had forgotten that the saw has 2 speeds. These are selected by a position on the rotary isolator (1-off-2).
I'm presuming the motor has 2 sets of windings to achieve the 2 speeds and the motor plate seems to tally up with that as it shows 2 speeds and also 2 power ratings.
I'm presuming the higher speed is the more powerful one?
Now, my thinking would be that I would just set up the vfd and use that for the speed control. I would either wire it direct to the high speed windings or leave the switch in position 2 all the time.
If that is correct then is it easy enough to find a vfd with some sort of input for a fast/slow switch rather than having to twiddle a knob or press buttons to change the speed? Or is it simple enough to program one to change rpm's by (example) 250rpm per press/turn?
Also, the motor plate shows both star and delta as 380v.
Does that mean this motor can't actually be run from 230v anyway (I was expecting one to be different from the other) or is that just an example of how many amps it will pull at 380v. Ie. It was pulling less when I was running it on a 415v supply and will pull more on 230v?
I dug it out at the weekend as I thought I would have a go at running it from single-phase via a vfd now they seem to be available at cheap prices!
Anyway, I'm not sure quite how simple this will be... I had forgotten that the saw has 2 speeds. These are selected by a position on the rotary isolator (1-off-2).
I'm presuming the motor has 2 sets of windings to achieve the 2 speeds and the motor plate seems to tally up with that as it shows 2 speeds and also 2 power ratings.
I'm presuming the higher speed is the more powerful one?
Now, my thinking would be that I would just set up the vfd and use that for the speed control. I would either wire it direct to the high speed windings or leave the switch in position 2 all the time.
If that is correct then is it easy enough to find a vfd with some sort of input for a fast/slow switch rather than having to twiddle a knob or press buttons to change the speed? Or is it simple enough to program one to change rpm's by (example) 250rpm per press/turn?
Also, the motor plate shows both star and delta as 380v.
Does that mean this motor can't actually be run from 230v anyway (I was expecting one to be different from the other) or is that just an example of how many amps it will pull at 380v. Ie. It was pulling less when I was running it on a 415v supply and will pull more on 230v?