Help with powering a three phase machine with single phase power.

[Sam Layton]

I have purchased an edge sander that is powered by a 3HP, three phase motor. I would like to use a VFD to power the sander rather than a phase converter. In looking at VFDs there are many to choose from. There is also large price range.

I do not know anything about VFD units, which brands are good, what price range to look at, or where to purchase the unit. Any, and all information would be appreciated.

Sam

[Joe Jensen]

I did some research on this 3 years ago when I put a VFD on a 3HP jointer. I chose a Teco brand, model FM50. It's a popular model. I ended up deciding to spend more and I bought one in a NEMA4 chassis which makes it pretty much dust proof. I paid $320, I think you can get a regular one for around $150. There are lots of folks here who are familiar with them so if you need help its easy to get it...joe

[Carroll Courtney]

Sam,like Joe I also went w/the Teco FM50 from http://www.factorymation.com/s.nl/sc.2/category.11/.f but mine was a 1hp which is fairly cheap compare to the larger hp.But one way to look at it is to set it up to operate other 3phase equipment w/a female cord cap rated for the load.Here is a pic of mine on a PM90.Keep us posted w/your route----Carroll

[Rick Potter]

Carroll,

You are saying that unit is not attached to the lathe, and it is not wired directly? You have a female plug on the cord we cannot see, and you can move the VFD from one machine to another?

Simplicity...true mark of a genius.

Rick Potter

[Van Huskey]

The Teco FM50 drive is going to be the most cost efficient and a perfect drive for a sander since none of the features not found on the higher dollar drives would be very useful for a sander.

I had considered making a roll around "power station" to power multiple 3 phase equipment. This would work fine as long as you didn't want to program them differently, however this may also be possible but I have not investigated it yet.

[Stephen Cherry]

I had considered making a roll around "power station" to power multiple 3 phase equipment. This would work fine as long as you didn't want to program them differently, however this may also be possible but I have not investigated it yet.

I think that the hitachi drives from drives wharehouse can be programmed with several setups for different motors. It's in the manual. The teco drives are a little cheaper, and work fine.

[Van Huskey]

I think that the hitachi drives from drives wharehouse can be programmed with several setups for different motors. It's in the manual. The teco drives are a little cheaper, and work fine.

I had gathered that but never bothered to figure it out. The higher level Teco drives and most of the Hitachi drives also have the removable keypad and you can buy them for the FM50 as well. There is a whole world of opportunity in VFDs.

[Carroll Courtney]

Rich this drive is only a 1hp and its hard wired into the lathe,I have a rotary converter setup for other machines.Buying and spending that much money for a 3hp which will be alittle over 300.00 if you go w/ the FM 50,but the better drive is the 7300 series.So to get the biggest bang for the bucks would be like Van said is to make it portable and run other machines that are 3hp and smaller.On the smaller machines you will not have OL protection since its setup for a 3hp using the drive,but I think that we all know our machines motors.To have the OL protection you can leave your starter mounted on the machine and run the drive through it.But you will not control the S/S through the starter its there only there for OL protection.----Carroll

[Jay Jeffery]

There is a lot of information out there about phase converters. There is even a sub forum on a CNC website that has all kinds of good info.
http://www.cnczone.com/forums/phase_converters_vfd/

When I looked into VFD's a few years ago, this site had the best prices.
http://www.factorymation.com/

I didn't end up setting up a VFD, though so I can't comment on the quality.

[keith jensen]

I'm not sure how you would have the OL protection using the heaters in the magnetic switch if you use a VFD. The instructions are very specific that you can not have anything between the VFD and the motor. I've been using the FM50 for a Powermatic 66. I wired sockets and plugs to make it portable if I wind up buying more three phase equipment.

[Sam Layton]

Thank you everyone for your input and help. Carroll, thanks for the photo. In your set up, do you turn the switch on to sent single phase power to the VFD? Then do you turn the lathe on with the VFD? Does the VFD serve as the switch, to turn machines on and off?

Thanks again everyone for your help and links. One think I like about the VFD is the ability to have variable speed. I think with an edge sander it would be good to be able to adjust the speed.

Sam

[John Lifer]

You REALLY should NOT have anything, Disconnect, switch or plugs between the VFD output and your machine's motor. Should be hard wired together. You can put switch between power and the VFD, and you can use remote wiring to turn motor on and off, but your asking for trouble with VFD if you forget and cut power between it and machine motor. These things are really one per motor. Just say'n!

[brent warner]

I have purchased vfd's from Dealers Electric, Motors, Motor, Variable Speeds, Reducers, Inverters, Transformers, Gearmotors and more! (http://www.dealerselectric.com/)
fair selection of vfd's and motors,too!
brent

[Dick Strauss]

FM50-203C for 3 hp machines is $185, not $300...

[Joe Jensen]

FM50-203C for 3 hp machines is $185, not $300...

I paid $320 for an FM50 in a NEMA 4 chassis. As I said above the normal chassis is much cheaper...joe

[Stephen Cherry]

One added thing- it is possible to use the original start stop switch, and contactor to supply the run command to the drive. What you would want to do is figure which two of three legs of incoming power lines of the machine are used to run the contactor. You would do this by first disconnecting the motor from the thermal overload, then supplying two of the single phase 220 lines to two of the three power inputs to the machine. If you get this right, the contactor will pull in when the start switch is pressed. If it dosn't work- try another combination of two power inputs to the contactor. When you get the power input right, the contactor will pull in when the start is pushed, and release when the stop is pushed.

Here is the trick- the left over contact of the contactor that does not have power can be used to start and stop the drive.

[Van Huskey]

You REALLY should NOT have anything, Disconnect, switch or plugs between the VFD output and your machine's motor. Should be hard wired together. You can put switch between power and the VFD, and you can use remote wiring to turn motor on and off, but your asking for trouble with VFD if you forget and cut power between it and machine motor. These things are really one per motor. Just say'n!


You are correct, I would never suggest putting a switch between the VFD and the motor, making a disconnect using a LOCKING plug would only be an issue if you disconnect the motor from the VFD with the VFD under power. However, most people are very careful in the shop dealing with power and machines, powering a machine whose switch is on can be dangerous or lethal in a shop, so I assume people have enough discipline with power connections to deal with this. If one is not, a disconnect probably is a bad call.

[Carroll Courtney]

Sam its there just to kill the power to the drive,some people have stated that they leave theirs power up all the time(I don't).On the front of the drive is a speed pod to set the hz or rpm or you can use the up/down arrow.As others have stated you should not have anything between the drive and the motor because of the temptation to turn on/off machines.Its only there for OL protection.With all of us doing our own VFD's,converters none will receive a UL listing. Let's all be careful---Carroll
Let me add this note,if I had deep pockets I would purchase a drive for each and every 3phase machine that I have.But I don't and if I did not have a homemade rotary phase converter,I would have just one VFD for the biggest hp and make it mobil.

[James Burrus]

sam I have a phase converter In my shop It works very will, It is a 5.5 Hp with a 40 amp braker to power It

JAMES

[Sam Layton]

Thanks again everyone for your help. All of the comments gave me a good understanding of what I need.

James, I considered a phase converter. However, I only have one three phase machine, and I like the idea of having variable speed on the sander. Now watch, after I get a VFD, another three phase machine will come along...

Carroll, I like the idea of having the switch to kill power to the FVD. I would not like to have it active all of the time. I think I am going to go with the Teco. I am going to install a disconnect in front of the VFD, as you did your switch. I have several disconnect on hand.

Thanks again everyone, Sam