What about 2hp 240v 3 phase vs 2hp DC treadmill motor for lathe or mill?

[Starlight Tools]

Hi All
I am new to the forum & will be greatfull for any info thanks.

I have just got a viceroy 11x24 lathe, with a 1.2 Hp motor 3ph & will be getting a VFD unit to run the motor.
reading this post & others i have got a lot of info on VFD's, not all ponting the same way.

1, a VFD with adv flux vecter control will develop nearly full torque at virtually any RPM.
but a std one will not, is a vector control a must. yes or no ????

2, is a IP65 (dri box) needed in a unheated room or garage (some say it is a must have) or will a IP20 (not a sealed box) be ok. Y/N

3, i was going to get a 3 Hp VFD for the 1.2 Hp motor, but may put a 3 Hp motor on, at a later date.
so do i get a 4 Hp VFD or not.

thankyou, great forum.
jeff

Jeff

Yes you want to stay with a Vector Drive VFD to get maximum preformance from it and your motor.

not sure about the box, but I would err on the side of caution. It is more a question of how likely will the box be to get wet, or condensation in it. If in doubt, protect it.

As for the size of VFD, if it is a newer VFD and it was designed as 3 Hp 220V single phase input, to 220V 3 phase output then you can use that VFD when you upgrade to the larger 3 HP motor. If the VFD is an older unit, or if it is not designed for 1 to 3 phase operation, then it must be dealt with differently. When VFD's were first designed, they were designed to vary the speed of motors in existing 3 phase circuits so they were to input 3 phase voltage, convert that to DC, then convert the DC back into 3 phase with a controllable varied frequency output which allowed the motor's speed to be changed. Now if this unit is only supplied with 1 phase then it has to be derated by 2/3 of it's rated output HP as it does not have the same amount of power being applied by leaving out the 3rd leg of the phases. With newer units the manufacturer has already taken this into account and rated the unit accordingly. Thus the fact that the VFD in my lathe is rated at 3 HP 3 Phase but only 2 HP 1 phase input and in order to use it as a phase converter, I would have to replace the VFD.

So in your case, you would have to use a 5 Hp VFD to operate a 3 HP motor, if it has not already been derated by the factory, or you can use a 3 Hp unit to control the 3 Hp motor if it is rated correctly for that application.

It is the same with my welding equipment. They are rated at 100 % duty cycle if they are run off of 3 phase power, but the duty cycle drops to 2/3 if they are powered by 1 phase.

Walter

 

[jeff_g1137]

Hi Walter
Thanks that is great, i can go & buy a VFD now, will cost £400+ in the UK.

Thanks Jeff

 

[jeff_g1137]

Hi
I was looking at a WEG CFW-08 VDF 2.2 Kw IP65 for £263+vat
Is WEG any good

thanks jeff

Ps were have all the posts gone

 

[pdentrem]

[QUOTEPs were have all the posts gone[/QUOTE]

Had to do a reset from an older date to correct the hackers leavings.
Pierre

 

[br-549]

Thanks guys,

I have a 9" SB lathe. Based upon this thread, it looks like I should ditch the treadmill drive I just picked up and go to a VFD when I can save the money. I have a 1.5hp single phase motor i will use in the mean time. I guess the only issue is the surge on start up, all of the lights in the house will dim for a second and I will need to have a 20 breaker on that line. (already have 12ga wire in that circuit)

I have seen several websites and testimonies on using the treadmill drive and motor - are they really that useless on a 9" lathe? What kind of equipment would this be useful for?

Regards,

B.

 

[John Hasler]

Thanks guys,

I have seen several websites and testimonies on using the treadmill drive and motor - are they really that useless on a 9" lathe? What kind of equipment would this be useful for?

B.

You should be able to make the treadmill motor work reasonably well if you know what you are doing. It will not put out 2hp for more than a few minutes. I wouldn't ask more than 1hp of it for long, and that only with forced-air cooling. It will (with the right controller) provide considerably more starting torque than an AC motor and (again, with the right controller) more speed range with good torque. It is a consumer product, though.

The controller that it comes with is probably open-loop. I'd convert it to closed-loop.

 

[br-549]

How do you convert it to closed loop? Is there an encoder or encoder input of some kind?

Thanks,

B.

 

[John Hasler]

How do you convert it to closed loop? Is there an encoder or encoder input of some kind?

I'd add an encoder (I recently added an encoder taken out of an old mechanical mouse to a DC motor) and add the necessary circuitry to make the controller closed loop. Requires engineering.