I now have a bridgeport vertical mill in my garage waiting to be hooked up. The motor on it says 230 volt 3 phase. I have a 230 volt outlet nearby that is rated at 50 amps. I looked in the ENCO catalog and they have phase converters in there for anywhere from $80 to almost $600. The more expensive ones are the rotary ones and the cheaper are the static ones. Does anyone have any experience with any of these?
thanks
Steve

 

oh yes we do!!!! i had the same problem and being an electrical contractor i really did some homework on this one. and this is what i found out. DO NOT go with a static, or electronic converter. i assume that you are not running a computer or fancy electronics on it, use digitals. go with the rotary!!! the rotarty actually makes 3 phase power. it's not the cleanest, but you only need clean for computers and there are kits that you can add on to clean it up. with a static converter all it does is give the wild leg a kick to get it running then drops out basically single phasing your motor, which cut the power down and also if you want to tap with your mill it's not going to happen. I went with ANDERSON CONVERTERS out of AZ 480-988-2804 www.andersonconverters.com the 5hp converter runns like $400. great folks very easy to get alonge with and they will answerall your questions also. very easy to install. you could even wire a plug to it so you can plug it in you outlet so you would still have your outlet to use for the welder if you wanted. the unit has an on off switch on the top of it. and actually i have mine running my surface grinder, my mill and still need to hook up my lift but it has no problem with running the surface grinder and mill at the same time.

 

why not build your own rotary phase converter it is easy to do email me and I can give you some help and you can save a bunch of money

 

You can get plans online (do a google search) for making a rotary. What you need is a static convertor (the plans will show you how to make one,) and a spare 3 phase motor. The motor needs to be at least as big as the one on the mill. The static convertor starts the spare motor, and the current is directed through it to the mill. 3 phase motors are often pretty cheap used cuz people usually want single phase. I ran a shop on a static convertor; the surface grinder got very hot; everything else ran fine, except only 2/3 the hp. I think it will shorten the life of the motors, tho'.

 

I run my Bridgeport off a VFD variable frequency drive... About $400 on EBAY. Easy to hook up (I am a fabricator not an electrician) no noise, no heat, soft start, auto brake and you can use it to control the speed (I don't, I run mine at 60hz).

 

Wouldn't it just be easier to replace the motor with a single phase 208- 230V capacitor run motor?

 

Yes it would. I do not know if anyone makes a direct replacement single phase motor for it. I did a quick search but only found replacement 3 phase motors for $600.
I may go with the rotary converter and give anderson a call as sparky suggested.
2many-trucks, what is a VFD? Is your mill a 3phase also? Mine is a series one, so it is not the variable speed, it has the pulleys.
Thanks for all the input!
Steve

 

If you can take the motor out and take it to a local motor shop, to see if they can match it up, also look at your machine and see if there is enough room to have a motor with a hump on it, (the location of the capacitor) or if the capacitor will have to be mounted remotely. If you are going with a remote capacitor you will need a steel mounting band and a rubber boot along with the capacitor. If you don't want to take the motor with you, get the make, M/n, S/n, Frame #**, HP, shaft size and keyway size and type. Also you'll need rotation from shaft end, CWSE or CCWSE. ** Very important # !

 

replacing a 3 phase mill motor with a single phase would be like shooting yourself in the foot. plus if you have ever tried to get the motor out of a mill you know what a pain it is. the 3 phase has more start up torque than a single phase even is it's a capasitor start motor. with the rotart converter it will cost you about $475 and take you about an hour or so to get it installed.

as for building your own. hey i'm all in favor of building your own stuff and i do it alot. but when i came to converters the made ons are nice and small and compact.

 

VFD = variable frequency drive

This device takes in power, 1 or 3 phase units are available, and outputs variable frequency power, 1 or 3 phase units are available. This device can output a variable frequency that can give you a variable speed device, within limits, from a normally single speed motor. I'm only somewhat familiar with large industrial units but I believe smaller 1 phase to 3 phase units are available. This may be what 2many-trucks is using.

I would like to hear more details on it. I often build my own stuff, and lately note that it costs more to build a solution than to buy one.

 

I see many freq drives on the industrial laundry equipment I repair, I must say they are the best improvement in machinery since PLC's.

The freq drive can be programmed for "ramp" speed...how fast it speeds up and slows down, also can be programmed for mulitple speeds by making different inputs.

If I was hooking up a mill....I think I would go with the freq drive, but you will need to get it programmed for your application, It is, however, easy to do yourself with the manual included with the freq drive. There are many sizes, be sure to investigate their capacity before you buy.

 

As far as replacing the motor goes- most mills have a strange looking motor that I've never seen anywhere else. The really old B'ports were available in single phase. I agree; 3 ph. have more power, and instant reversing, which I use all the time for tapping.

 

I have two Bridgeport mills that run on Mitsubishi VFDs. One is an Explorer (CNC) and one is a Series 1 with a variable speed head. Both drives are 3hp 3ph drives. They de rate them to about 1 1/2hp when the input voltage is single phase.

My clausing lathe had hydraulic variable that leaked bad. I put new standard sheaves and belts on, bought a drive and $2 potentiometer. It works so well I rarely have to use back gear.

My shop has a 20hp rotary phase converter that I use for my big machines. It works good but the idea of running that motor to generate a third leg of power… seems wasteful.

My bandsaw is next to be converted. I found a $125.00 drive on EBAY… No more changing the belt position (3 speed).

The programing manual can be intimidating... Most of the features are not needed... I figured it out, can't be that hard

 

you are correct converters are wastefull when they are runn'n with no load on them. so can hook up a remote switch to them so they turn on when load is applied. there is a few second delay form the time you turn the machine on till the time it starts. but for those of us with only single phase power it's the price we pay. i have grown up on and around farms that run 3 phase converts for months on end in harvest season and it is cheaper than paying the power company to bring in the 3 phase. and for myself with a small personal shop that i am not using my 3 phase every day it seems to be the best bang for the buck. it was alot cheaper to get a converter than to get 3 phase power or to replace the motors on the equipment. all kinds of things to think about.

 

I think I'm leaning towards the 3hp rotary phase converter from anderson since the mill has a 1hp motor. I thought the hardest part was going to be getting the mill off my truck and into the garage. That was easy compared to figuring out how to hook it up.
I'm going to wait a couple of weeks though because I might be getting a lathe, so I'm sure that would require a bigger converter. If that is the case, I'd like to have just one converter that I could use for both machines, one at a time of course.
Steve