I just bought (at auction) a 3 phase Delta/Rockwell shaper.
My home like most is single phase. The price of the shaper was too good to pass up so my thought is to wire the machine for single phase and buy a single phase 3hp reversible motor.
For the price of a phase converter I could get myself a new motor instead plus it would increase the value of my shaper. A used single phase 2hp shaper seems to be going for around $1200 while 3 phase units sell for $900 (used of course). So,if I was to sell the unit someday I could make out pretty well.
Has anyone out there ever done this before? Baldor has a good reputation for motors do they make a direct replacement? I would have to imagine that a single phase machine is built the same as a 3 phase and a motor switch should be easy to do. Maybe change a mounting bracket and some other hardware.
Any experience or suggestions out there?
Replies
Hey TJ,
A single phase motor of the same HP will be nearly twice the size of the 3Ø motor. You might want to make sure that you have the space in the cabinet.
A 3Ø motor also has no brushes and will last longer with less maintenance. Also a variable frequency drive will allow you to run the 3Ø motor at a infinitely variable speed.
Tom
TJ
I have several 3 phase tools, and I would never swap out a motor on any of them with a single phase one. It's easier to just get a phase converter. Use a rotary, not a static converter. Many available on ebay.
3 phase motors run and operate better than single phase, with less to break down.
Jeff
I've seen big buck variable frequency drives (in the hp range you need) going for very reasonable money on ebay.
Tj,
Tms is correct about the size. I have that same machine in 3 phase. I am pretty sure that if you did find a 3hp or 2hp single phase it would be too bulky, to say noyhing of the huge weight.
He is incorrect about the brushes though-nowadays single phase motors suitable for this application are induction type without brushes.
Is there no chance of your utility providing 3 phase into your house-otherwise you'll have to get a converter as previously mentioned
Check with your local motor repair shop about getting a Variable Frequency Drive to run it on on single phase power.. It will give you soft start. reverse, infinitely variable speed, not to mention being able to double the motors rpm (great for using a router bit) and will cost about the same as changing the motor. That would be far more valuable than a single pahse motor in my opinion.
Single phase motors don't have brushes by the way. There would be no problem with fitting a single phase motor in the shaper.
http://www.deltamachinery.com/index.asp?e=136&p=959
A 5 hp motor is available in single phase as well if you go that route. It will fit in the cabinet of the older machines as well. I worked for a dealer and was a Delta tech. I'd prefer the inverter myself for the extra benefits I mentioned before.
Edited 6/7/2005 3:59 pm ET by rick3ddd
I would call your power company.. They may bring it in if possible... May COST ya' thought... ALOT..
The other post on motor size is TRUE.. May or may not fit! Good luck.. I hope it works out for you..
Chances are the local power company won't be interested in giving you a three phase service to your house (and even if they are it will cost major $$$.) I agree that a good choice for your situation is a variable frequency drive. They can be connected to your regular single phase breaker panel and still put out three phase power to the motor, they are a convenient way to get a soft start / soft stop function, you can vary the motor speed and they are reversible. Also, the price has been coming down quite a bit in recent years.
About the least expensive one I've seen is from Automation Direct, you can buy them online for $325: http://web4.automationdirect.com/adc/Shopping/Catalog/AC_Drives_-z-_Motors/GS2_(115_-z-_230_-z-_460_VAC_V-z-Hz_Control)/GS2-23P0
Thanks for the reply Stuart!With the Variable style phase converters do you loose torque when you vary the speed? Would I still lose 1/3 of my rated power like a standard static converter? I found a 5hp rotary converter for just under $500.00. After reading all the responses I am leaning towards the rotary converter. Down the road I may get another 3 phase unit and this might be the least expensive route in the long run.Tom
The VFD will give full HP unless you try to slow the motor down too much. The idea of doubling the motors speed is a plus for using router bits. This was a common technique on moulders to get a better cut and faster feed.
A rotary will run multiple machines. Go to this site for more technical info. You can make your own rotary with a static and slave motor. Good tech help at phase-amatic. Best place to buy them is http://www.use-enco.com
http://www.phase-a-matic.com/StaticDescription.htm
Full or close to full HP can usually be obtained by running a three-phase motor and PHASE-A-MATIC™ Static Converter combination as shown on the Installation Instructions. When running unloaded, the windings of the motor function as a rotary transformer or generator while consuming very little extra power. The Idler Motor needs to be at least 50% larger than the largest motor that you want to run to accommodate the higher starting current. A good quality 3600 RPM, three phase wye-wound, 220V motor is the best choice. 1800 RPM motors can be used on applications not heavily loaded. Used three-phase motors are inexpensive and readily available.
When using this method, it is possible to run multiple machines as long as the idler motor is large enough to handle the largest load it would ever have at any one time. For instant reversing of the load motor, as in rigid tapping, the idler motor must be a minimum of twice the HP rating of the load motor, and perhaps more.
The Static Converter is sized to the HP of the idler motor, not the load motor(s).
http://www.phaseperfect.com/faqs.htm is the latest for phase converter technlogy.
"With the Variable style phase converters do you loose torque when you vary the speed? Would I still lose 1/3 of my rated power like a standard static converter? I found a 5hp rotary converter for just under $500.00. After reading all the responses I am leaning towards the rotary converter. Down the road I may get another 3 phase unit and this might be the least expensive route in the long run."Variable frequency drives (or VFDs as they are called) can be either constant torque or variable torque; I believe the one I linked to in my earlier message is a constant torque model. The static or rotary phase converters will work, particularly if you can get one for a decent price. They aren't the greatest for continuous use, but for power tools that are run intermittently they can be OK. If you are handy, there are plans floating around out there on the Internet for building your own static phase converter. A buddy of mine has a homebuilt one he uses to run his Bridgeport mill and it seems to work fine.
At 5hp or less, a static phase convertor takes 25% max of your power and that is not an issue as long as you have a motor with a 1.1 to 1.5 service factor, which means it can handle the voltage drop. A 1.0 service factor motor must have its rated power. It is hard to imagine that you would notice 2.25hp rather than 3hp on a bandsaw, table saw or drill press, any tool that operates or starts NOT under load. Loaded machines (air compressors, wide belt sanders, etc) are not good candidates for static phase convertors and should have a rotary rated at twice the HP of the machines motor. Hope this helps.... Aloha, Mike
Mike:That helps, my motor has a 1.1 service factor and it would start with no load being a router. A VFD starts around $800 which is twice what I paid for my machine and I wonder what it would do to the motor running at more than its rated speed. Besides there are pulleys for different speeds I can change if I wish to.A rotary phase converter goes for around $400 to $500 by the time you figure in various components it might be higher. The same machine was sold as a single phase, my brother has one. The same machine is now called an "X5" and that is a single phase machine.
If I was a production shop running full time three phase might be the way to go. But right now I am a weekend warrior, the machine might see heavy use for a day or so then be idle for quite awhile. I can always convert to 3phase at a latter date if I should decide to grow.Thanks for everyone's input, this is the first time I have used this forum. I got more information than I bargined for!
Phase-a-matic makes a static phase convertor for a hundred bucks. Works great and easy to hook up. Aloha, Mike
This forum post is now archived. Commenting has been disabled