cnc lathe 3 phase to single phase conversion?

coyote06 · Nov 1, 2020

My new to me cnc lathe arrived last Friday and had a good look at the wiring and appears most of the stuff runs on single phase except the spindle motor.
The spindle motor is 3 phase and run off a vfd , I'm sure some of these machines must be able to be rewired to run on single phase.

Right now I need to power it up in my single phase shop and wondering if a retrofit to single phase might be a good option.

The machine is wired for 460V 3 phase and there are 2 single phase transformers in the machine that feed the controller and servo drives.

From what I can tell if the vfd was replaced with a single phase vfd it might be doable .

Anyone ever done this or have some good advice on where to start machine is 6KW with a 4KW spindle motor drives and servo are Baldor

DouglasJRizzo · Nov 1, 2020

Perhaps a rotary converter? What's the incoming voltage to the shop?

Guest · Nov 1, 2020

What brand is it and what controller? Every CNC lathe I ever owned or worked on for someone else had a 3 phase spindle motor and ever other motor in them was 3 phase except for the fan motors. The axis motors, hydraulic pump and coolant pump were also 3 phase.

coyote06 · Nov 1, 2020

Dualkit said:
What brand is it and what controller? Every CNC lathe I ever owned or worked on for someone else had a 3 phase spindle motor and ever other motor in them was 3 phase except for the fan motors. The axis motors, hydraulic pump and coolant pump were also 3 phase.

You're probably right about the coolant and hydraulic pump I never considered them , the reason I started thinking about doing it was that I was searching for the best way to power it up and read some guys had done it.

This is an older machine it's a clawsing metosa EL1440CS made by Pinacho with a fagor 800T control

coyote06 · Nov 1, 2020

DouglasJRizzo said:
Perhaps a rotary converter? What's the incoming voltage to the shop?

That's what I was considering, my shop has 230V 200 amp the machine is 6KW 460v 3 phase so far I looked at American rotary phase and phase quest which is by far the best price.

They both guarantee they will run cnc equipment but read that some guys had converted their machine to run on single phase which would be nice

50BMG DUDE · Nov 2, 2020

coyote06 said:
That's what I was considering, my shop has 230V 200 amp the machine is 6KW 460v 3 phase so far I looked at American rotary phase and phase quest which is by far the best price.

They both guarantee they will run cnc equipment but read that some guys had converted their machine to run on single phase which would be nice

Check out Phoenix Pase converters on Ebay. I have a 25HP and a 60 HP - I run 3 VMCs (Doosan and Hurco) A sodick Wire and 3) 2 axis lathes (clausing and Hurco) along with all of my manual stuff

Never had any issues.

Vancbiker · Nov 3, 2020

I don't know anything about your machine, but most CNC controls are single phase anyway. Some VFDs that are designed for 3 phase input work fine on single phase. Some brands of servo drives that are designed for 3 phase input work fine on single phase.

I've been running my Mori Seiki with Mitsu control on single phase for over 7 years now. Only real work to the "conversion" was adding a VFD to run the coolant pump. That was less cost than replacing the coolant pump with a single phase unit. The machine does not have a hydraulic unit. It also uses grease lubed ways so no lube pump to consider in the change.

A sharp CNC tech would be able to have a quick look at it and tell you your options. The trouble there is finding a sharp tech. They are few and far between.

twr · Nov 5, 2020

Hi how about the one above [Vancbiker very sharp] o ya he is retired hahah!!

Vancbiker · Nov 5, 2020

twr said:
Hi how about the one above [Vancbiker very sharp] o ya he is retired hahah!!

Ya know, there are times when I think I ought to get back in the biz. I hear many horror stories from folks I know about how long some doofus dicked around with a machine before finally coming up with a fix or sometimes not. Pretty sure there's a couple hundred k$ a year waiting waiting to be scooped up by doing efficient, timely, professional service.

twr · Nov 5, 2020

Kevin that couple hundred k$ a year is waiting for you to come out of retirement!!!

swatkins · Nov 6, 2020

My bridgeport TC 22 is a three phase machine running on single phase 220. IT was super simple to convert as everything in the machine, with the exception of the spindle, every motor and control was in effect running off of two hot legs of the three phase lines already... The VFD was making three phase for the spindle off of two legs and it was a simple matter to jump one connection so that everything on the machine was now on those two lines...

Here is a video of the control cabinet where I made the change....

Good luck with yours!

coyote06 · Nov 8, 2020

Well I'm on the convert to single phase boat again , now I need to find a wiring diagram according to my electrician/ cnc guy to see what needs to be done.

When I got the machine it came with a lathe manual but other than wiring diagrams for the components of the electronics I don't have a diagram for the machine

Hardplates · Nov 8, 2020

Be aware that if you run a VFD off single phase when it is designed for 3 phase input you are asking 2/3 of the rectification section to do the work of what the entire rectification section was built for, diodes, IGBTs or whatever.

Personally when doing that I like to see the drive oversized. My 15hp compressor runs on a 40hp Square D drive that is supplied with 440 volt single phase

coyote06 · Nov 8, 2020

Hardplates said:
Be aware that if you run a VFD off single phase when it is designed for 3 phase input you are asking 2/3 of the rectification section to do the work of what the entire rectification section was built for, diodes, IGBTs or whatever.

Personally when doing that I like to see the drive oversized. My 15hp compressor runs on a 40hp Square D drive that is supplied with 440 volt single phase

That was the first thing I considered and figure if I do this I will replace the vfd with a larger one , the spindle motor is 4kw so a 7.5kw might just do it .

The first thing I need is a wiring diagram and going to try and get one hopefully the manufacturer would have it

Vancbiker · Nov 8, 2020

Hardplates said:
Be aware that if you run a VFD off single phase when it is designed for 3 phase input you are asking 2/3 of the rectification section to do the work of what the entire rectification section was built for, diodes, IGBTs or whatever.

Personally when doing that I like to see the drive oversized. My 15hp compressor runs on a 40hp Square D drive that is supplied with 440 volt single phase

In the end it just about power (Watts). What I have found is that most low voltage 3 phase VFDs have a design current voltage of 208V 3ph. The diode module is spec'd for that current with some safety factor. When running off single phase most folks will be 230-240V at the input. The increased voltage offsets some of the "lost" power (Watts) that the single phase has versus the 3 phase input. This usually allows the rectification section of the drive to be within the spec of the components. It can easily be verified by monitoring an ammeter on an input leg while commanding max spindle speed. If the current draw is too close to the rated input current, most drives can be adjusted to a longer accel time which will reduce the load on the VFD.

Search

Largest Manufacturing Technology Community on the Web

Search

cnc lathe 3 phase to single phase conversion?

coyote06

Aluminum

DouglasJRizzo

Titanium

Guest

Guest

coyote06

Aluminum

coyote06

Aluminum

50BMG DUDE

Cast Iron

Vancbiker

Diamond

twr

Hot Rolled

Vancbiker

Diamond

twr

Hot Rolled

swatkins

Titanium

coyote06

Aluminum

Hardplates

Stainless

coyote06

Aluminum

Vancbiker

Diamond

Similar threads