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View Full Version : 3 Phase to single Phase conversion?


rokcrln
03-14-2010, 09:10 AM
Hey guys I just got a great deal on a power plate roller that is 50"x16ga but it is 3 phase and my shop is single. I went into this knowing that worst case I am looking at $700 for a real good rotary phase converter that will do the job. With that being said it is still a great deal I got and this thing has almost zero use on it. But my question is can I go a different route and do a single phase 220 motor on it or a different type of phase converter? I have a power bead roller that is 110V single phase but with a 3 phase motor but I am not sure how it was done.

The slip roll is a 3 phase 220V with forward and reverse 1hp and a 60:1 gear reduction. It is made by Birmingham and is the Taiwan not the china version (I was told it is much better) but I have seen simular versions with a 2hp 220V single phase set up that I would like to try and do. The foot controls are all 24v relays and what not so that should be simple to figure out but the rest I am at a loss for and could really use some advice.

Here are a few pics and if more are needed please let me know what you might need and I will do what ever I can.

Thank you very much for any help with this.

Kevin
LFD Inc.

ESjaavik
03-14-2010, 09:26 AM
Buy a VFD (Variable Frequency Drive) to go between the 220V/1ph outlet and the 220V/3ph motor. Preferrably a 1KW unit.

Dont Ebuy it unless you know a bit about these. And since you're asking I assume you don't. All the seller needs to know to select you the right one is your photo #2 and that you only have 1ph outlets. VFD's come with 3ph input in all sizes and 1ph upto about 2-3KW.

As a bonus you get to set the speed of your rollers using a simple potentiometer and forward/reverse using small, even tiny switches. With most of them you also can hook up a voltmeter and use it as speed readout.

rokcrln
03-14-2010, 12:02 PM
Thank you for the info. I was leading toward going this way but wanted some other input. I have a Lazze power bead roller that is 110V single phase that runs a 3 phase .5hp motor and that uses a Baldor converter. I want to be able to still use my foot controls so as long as I can wire those in I will be set. I also found that I will most likely be removing all the current controls off this unit once I change over to a VFD right?

Thanks again.

Kevin
LFD Inc.

ESjaavik
03-14-2010, 12:25 PM
I'm not too sure what I see in the picture but I'll try.

- 2 Fuses. Keep them, between grid and VFD. Why are there not 3 on 3ph:confused:

- 2 Contactors. Probably run and direction. The one in the center with overcurrent protection for the motor. Not needed. VFD have that built in.

- 1 Transformer. Probably to have the pedals at 24V and isolated in case the cord is damaged. (for safety). So the contactors are probably 24V.

- 1 relay between fuses and contactor. Dunno what for. Maybe for key switch?

-On the door a key switch. Keep it.

Usually a VFD comes with one Run input and one Direction input. You need to program it to use those inputs for Run Forward and Run Reverse. Then connect to pedal switches. If you step on both it will usually run forward. These inputs are low voltage generated by the VFD. On the VFDs I know these inputs are not toggled so it will stop when you let go of the pedal. This can be changed to toggle function with some small relays. Ramp up/down time is a parameter that can be changed in the VFD. Useful as you can control speed also by blipping the pedal, pot will then be max speed.

So are the voltage for the speed control pot. So I would put that in a plastic box on a cord and with a magnet on the bottom so you can put it at the most convenient point.

Rick (madera)
03-14-2010, 12:43 PM
VFD's are great I have 2. One is for my Pullmax 2HP 220 1phase in 220 3phase out
one one my bead roller 1/2hp 110v in 220 3phase out
that said you already have F/R pedal I think I would just buy a static phase converter and put on it.You will lose 1/3 HP but for your application it shouldn't hurt. alot cheaper about $60 on EBAY EZ to wire also:)

rokcrln
03-14-2010, 01:44 PM
This unit is already reduced 60:1 with the gear box and will only run at 16rpm max and that is plenty slow for roll forming so I don't really need a speed control like my bead roller has. That being said if a static phase converter would do the job and I can just wire it right into what I have now that that would be simple, fast and I assume safe. That would also let me keep the door on/off switch but it will not be plugged in when not in use so safe on that end as well.

With the Static do you need to up size the converter? To say a 2 or 3 hp for my 1 hp motor?

And yes the foot control is 24V and looks to run the 2 contactors.


Kevin
LFD Inc.

Rick (madera)
03-14-2010, 02:04 PM
they sell one that is 1HP min. 3 HP max should work great

bobadame
03-14-2010, 04:18 PM
It's a 1 HP motor. Unless you need 3 phase for other machines I'd just replace the motor with a single phase.

rokcrln
03-14-2010, 04:22 PM
It's a 1 HP motor. Unless you need 3 phase for other machines I'd just replace the motor with a single phase.

I was looking and for a motor with the correct frame to bolt to the gear box was around a $1K:o So if I can do it for under a few hundred that will leave more $ for my projects.

Kevin
LFD Inc.

bobadame
03-14-2010, 05:37 PM
I didn't notice that it was a face mount motor. I think they are called C frame. I'll have to check on that. I have one here. I'll check the dimensions and the RPM tomorrow.

Doug98105
03-14-2010, 07:05 PM
Kevin,

You have what looks like a nice machine.

There's no point in screwing it up by changing motors or the control system. Either of those changes will drastically lower it's resale value.

The machine probably has instant reverse now which is a very nice feature, a single phase motor will not do that.

VFD's are not an option without total elimination of the motor controls you now have.

The best option is to create 3 phase somehow. A static converter will do it. A rotary will too. My choice is the rotary, then you'll have 3 phase available for other machines you're sure to come across.

You can find a "kit" on ebay to build your own rotary. The kits don't include the idler motor. That's something that's dirt cheap on the surplus market. My guess is for a couple hundred bucks you can put together a rotary (I've done it for much less in years past).

Doug

Marty Comstock
03-15-2010, 02:44 AM
I agree with Doug, Keep it simple. I see many putting VFD's on machines bucause they are cool and dont even understand how to use them. Dont get me wrong, I LOVE variable speed, but there are drawbacks.

Rotarys are very simple, so easy to intstall even I can do it.

Also, be super careful that you dont hook up your wild leg to the control voltage feed, it can and will fry your coils in starters and such.

Marty

shortbus
03-15-2010, 06:48 AM
Kevin,

VFD's are not an option without total elimination of the motor controls you now have.

The best option is to create 3 phase somehow. A static converter will do it. A rotary will too. My choice is the rotary, then you'll have 3 phase available for other machines you're sure to come across.


Doug

That is not a totally true statement. I have a Bridgeport and a surface grinder that I run with one VFD(not at the same time.) I put an outlet on the VFD and change between machines as needed. The VFD is set at 60hZ and i use the controls on the machines as they originally were.

cary

Doug98105
03-15-2010, 08:29 AM
That is not a totally true statement. I have a Bridgeport and a surface grinder that I run with one VFD(not at the same time.) I put an outlet on the VFD and change between machines as needed. The VFD is set at 60hZ and i use the controls on the machines as they originally were.

cary

Cary,

If you've done it without problems so far, you're lucky.

The instruction manuals for all the VFD's I have caution against having any "down stream" switching. That would be between the driven motor and the VFD. Check your instruction manual.

Quoting from the warning in the Teco-Westinghouse VFD manual: "Do not use a separate device to switch ON or OFF motor during operation. The AC drive may experience an over-current failure."

Doug

bobadame
03-15-2010, 09:22 AM
Kevin, Doug raises a good point. If you need the instant reverse feature that is built into the machine, a rotary converter is a good choice. A capacity start single phase motor will draw huge amps if you slam it into reverse or it might not reverse at all. A static converter won't let you to instant reverse either, at least mine won't. I have to use the brake on my mill before I reverse otherwise it continues the same direction. Not good when I'm power tapping. A rotary converter will let you use the machine as it was designed to be used.

Jim Stabe
03-15-2010, 11:13 AM
I built my own rotary converter and it isn't that difficult or expensive. My 3hp lathe came with a static converter but it wouldn't start the machine in the highest (2000 rpm) speed without physically spinning the chuck and I didn't want my hands wrapped around the chuck when it took hold. I since got a 3hp mill and it runs off the same rotary converter circuit.

I used a 7.5hp 3 phase motor that I bought for $50, just make sure the bearings are quiet by spinning the shaft. If you have an electrical surplus store close by you can buy the rest of the components you need fairly cheap. I posted pictures of mine with the schematic I used. I also have a really good article about phase converters but it is too big to attach here. PM me with your email address and I will send you the file.

3478

3479

3480

ESjaavik
03-15-2010, 11:14 AM
"Do not use a separate device to switch ON or OFF motor during operation. The AC drive may experience an over-current failure."
Doug
I don't think that is what he does.
You can switch the secondary safely if only doing it after turning off the input voltage to the VFD and wainting till the UV error goes out. Usually 2-5 seconds.

But if the motors are not the same or close, the VFD should be reparametrized when swapping. It will work without, but not with the kind of motor protection a VFD should give.

How many displays, buttons and blinking lights does a static converter have? I don't see that as an option. :lol::lol:

Jim Stabe
03-15-2010, 11:19 AM
Not sure why the pictures didn't show up

3481

3482

Edit - Didn't work that time either

rokcrln
03-16-2010, 03:23 PM
Thanks guys I am going with a Rotary converter from Temco. They are a local company so no shipping and the unit I am getting is a 3HP unit that is CNC rated with +- 5%. I can run another unit off it at the same time (depending on size) and new it is $350 with a 6yr warranty.

Thanks for all the advise and help!

Kevin
LFD Inc.

Gitzit
03-16-2010, 03:38 PM
Jim, On the converter you made do you hold in the start switch till the motor is up to speed or is it automatic after you push it? The one I made I must hold it in till it's running.

Neil
www.gogitzit.com (http://www.gogitzit.com)

Jim Stabe
03-16-2010, 06:29 PM
Jim, On the converter you made do you hold in the start switch till the motor is up to speed or is it automatic after you push it? The one I made I must hold it in till it's running.

Neil
www.gogitzit.com (http://www.gogitzit.com)
Yes, I didn't want to go through the effort to make a circuit to do it. All it takes is a fraction of a second stab at the button and it's running. Makes an ugly noise if you hold it too long.

rokcrln
03-20-2010, 06:11 PM
Well I picked up a Rotary unit from Temco in Fremont Ca. and then I added a 30amp breaker before the unit and it works great. All the original functions work perfect. I had a test piece to try that was about 8x40 16 ga and I first ran it through the short direction and after a few adjustment it mad a nice hoop. Then I took it and quickly straightened it out just enough to stick it in up side down from the first try and once again it curved great with zero spring back. Then the last test was taking the same piece and straighten it out by stepping on it to flatten then I put it in long ways and after several passes adjusting it each time it made a great little drive shaft tunnel shape.

I mounted it on 4 rubber isolators that were recommended to me at the time of purchase and I am glad I did because this unit is very quiet and you can not feel any vibration in the roller it self when the converter is running. All in all it took about 2 hours to instal and wire but was very simple with basic home wiring knowledge. Only part left is to get a few clamps for the cord so I can strap it above the breaker so their is not any tension on the connectors.

Kevin
LFD Inc.

Rick (madera)
03-20-2010, 07:51 PM
When PG&E told me it would be 6 months $5000 to get 3 phase to my shop I went to Temco and bought a 20 HP RPC I wired into a 3 phase breaker box it worked great! I wired in a light to let me know it was on:)
glad it worked out for you

Jim Stabe
03-22-2010, 07:42 AM
Someone sent me a PM with their email address asking for the article on converters. It has disappeared so could you please send it to me again.

Thanks

Jim