VFD help

[brian zawatsky]

Not sure if this is the right subforum for this post, but here goes anyway.
I have a chance to buy a Baldor 12" grinder pretty cheap. Problem is its 3 phase, and my shop is in my basement. I don't want to have to put a big heavy loud rotary phase converter down there, and my wife would probably kill me if I did anyway.
Could I add a VFD to the machine to allow me to run it on 240v single phase power?

[Malcolm McLeod]

Yes. Many are rated for 240V/1ph input and 240v/3ph output. Just check the specs and make sure the VFD ratings match the motor.

[John K Jordan]

Not sure if this is the right subforum for this post, but here goes anyway.
I have a chance to buy a Baldor 12" grinder pretty cheap. Problem is its 3 phase, and my shop is in my basement. I don't want to have to put a big heavy loud rotary phase converter down there, and my wife would probably kill me if I did anyway. Could I add a VFD to the machine to allow me to run it on 240v single phase power?

I know people who have done that and others who wish they could find a nice 3-phase baldor for that reason. I wouldn't mind putting a nice 3-phase motor and VFD on an old milling machine here to allow variable speed without changing the belts. I bought a VFD and programmed it to drive the motor on one of my lathes. It wasn't hard once I knew how! :-) I looked at the programming on several and they were very close to the same. They used different control lines for speed control, start/stop, reverse, etc. Those things are amazingly flexible which makes them seem complicated at first.

To get good advice you might post the specs on the grinder, in particular the HP or amperage on the motor plate. If the motor does not need too much power you can even run it on 110v single phase. Some VFDs will allow either 110 or 220v.

JKJ

[Carroll Courtney]

Another benefit is you can have a slow speed grinder and a high rpm grinder all in one.I have an 1800rpm ginder and love it,but also like the 3600 rpm ginder,so you can have both all in one package.This is who I purchase mine from http://www.factorymation.com/Product...M50-101-C.html but there are several companys out there just check to see if they have phone support.-----Carroll

[Dennis Ford]

As long as it is 3 hp or less; you should not have problems. It can be done on larger motors but gets more expensive quickly.

[Mike Heidrick]

As long as it is 3 hp or less; you should not have problems. It can be done on larger motors but gets more expensive quickly.

You can do 5hp 4kw on 240V single phase in for $197 these days.

[Bruce Wrenn]

Not sure where you got the idea that RPC's are loud. One I built for my neighbor sits under overhang of house into his shop. Only if you looked for it would you find or hear it. Basically only noise it makes is when it comes up to speed and latching relay kicks in.

[Dennis Rech]

There are other benefits of using VFDs with 3 phase motors on machinery.
You get a programmable soft start; no more bang on and bang off. You get to program the amount of time that the grinder comes up to speed and also the time to slow it back down. On a grinder, braking is desirable.
The VFD provides over-current protection and shuts the power off if you lose a leg of 3 phase. No damaging the motor if a wire comes loose.
Adding a toggle switch gives reverse should you want it.
It also allows the motor to run at up to twice the speed should you need it.
I have 5 of them in my shop and each is of a different make. Some have very intuitive programing and some do not.
I recommend that you download the instruction manual for the unit prior to purchase and make sure that the programing makes sense to you.
Also, you should probably mount the VFD in a box. The wiring can be a bit exposed if you just hang the VFD on the equipment.
Dennis

[Rich Riddle]

I use VFD on several three phase machines......what size motor is the grinder?

[brian zawatsky]

Thanks for the replies guys. I opted not to buy that particular grinder, as the guy selling it did not have the ability to demonstrate it under power. So the hunt continues

[Doug Ladendorf]

There isn't too much to go wrong with three phase motors. You might need to change the bearings but you can usually tell just by spinning. One thing to be aware of is if it is 440V only. They you would also need a transformer and it may affect the value proposition.

[Rich Riddle]

Thanks for the replies guys. I opted not to buy that particular grinder, as the guy selling it did not have the ability to demonstrate it under power. So the hunt continues

I agree with your decision. Most who cannot demonstrate them are simply "flippers" who have no idea what they are doing.

[Rick Lizek]

If it's 1 hp you can run it on 120 volts. You might be able to 1-1/2 hp on 120 volts. www.factorymation.com. Good technical help too.

[David Lindenthal]

Hi Guys. A quick question if you don't mind. I came across some 3PHs machines from a school wood shop that was being shut done. The machines ranged from 1HP to 2HP about 5 of them. I was wondering can a VFD be set up to switch from one machine to the next provided that only 1 machine was used at a time and that the VFD was capable of handling 2-3HP. Thanks for any help

[mike wacker]

David,

Pretty much anything can be done as you described. But you better understand what your doing.