Thread: Single to Three phase converter

Hello to all, and hopefully one of you Lads can provide advice... I have a 3 phase Milling machine and want to run it off a single phase supply. It has a 1.5 HP motor on it.

I need to know the best way to jump.

Kind Regards, John

If only one motor, probably a VFD would be "easiest". Other options are a static or rotary phase converter, or even a single phase motor swap.

Hi John,

I am using this unit and it seems ok. The extra knob on the control pad for frequency control is nice. Search for "VFD" in the forum, there are a few threads
1500W 2HP 240V 7A Single Three Phase Variable Frequency Drive Inverter VFD | eBay

If you go the vfd way make sure you can configure the motor to delta depending on which motor some just need to have the jumpers changed ive just converted a Tom Senior mill which didnt have jumpers but with a bit of careful study it wasnt too hard to find the star point junction and change it.If your not too sure i suggest a motor rewinder or sparky should be consulted
John

It would be useful if you could post pictures of the motor data plate and the motor connector block. There may be a diagram of the motor connections under the cover of the motor connection block as well.

Dean

I agree with Dean: Show us the motor and we'll help you avoid some traps.
Also, the $150 VFD jackaroo pointed out to you is the better choice over the lower cost ones currently on eBay. It is a Huanyang and lots of people here have them and have gathered lots of experience with them (including me). The lower cost current crop isaninferior product with minimal settings only. I got 'trapped' by the price andthe very similar look of them.They are significantly different to the Huanyangs.
You other alternative is to contact Chris Parks by PM (a member on this forum) who can source a Powtron VFD which is a bit better still.

Hi Lads, Thanks for the replies... I have been a bit off colour lately and have not had a chance to reply. I have taken a few pictures and will post them when I get over this minor OP this coming Monday. I seem to take a lot longer to do anything these days, bugger to be getting Old.

John

Get well soon, John

//metalworkforums.com/f303/t198...b-600-a/page-5

posts 4 thought to 10 is me rambling through the same problem!
good luck

Having trouble getting around sending a couple of pictures... I'll try with this message...NO Luck

Try looking at this post

//metalworkforums.com/f36/t1688...os-attachments

Dean

Well I think I have attached two photo's containing the needed info, and thanks to Dean for pointing me in the right direction. I hope that it will provide enough to enable a solution to my problem. And, I only need the
device for one motor. no info inside the cover.

I do have a three phase motor and controller on a VICMARC VL-300 wood lathe but it was all setup when I bought it many years ago. I did make a four foot extension to enable me to turn stuff up to
eight feet long. My brother wanted me to turn the posts for a 4 poster bed he wanted, out of cedar and that was the reason for the extension. The lathe is able to run from about 30 to 3000 revolutions per minute at
the turn of the Pot...

John

If I'm reading that right, it's a 2 speed motor ... not 100% sure, but I don't think you can run them off a VFD (or at the very least you will lose the dual speed facility)

That is indeed a 2 speed (Dahlander, ∆/2Y) motor.

It is wired for 415V only.

On either speed (even the ∆ config) it will only run at half power on 240V 3P.

It can be rewired internally only for the 2Y side, converting it to a 2∆ which will develop full power at 240V 3P.
I don't think motor rewinders would approve of this and it would be better and not much more expensive to buy a new dedicated 240V 3P motor.

Does the mill have 2 speed settings?

It seems the motor is Delta/YY. Normally you would find which connections were the Delta ones. This would be the black wires labelled with either 1UVW or 2UVW. These delta connections would be connected to the output of the VFD.

Delta will give 1480rpm and YY will give 2850rpm if I am reading that plate correctly.

Dean