School me on phase converters

[Rixter58]

Got a screaming deal on a 3 phase Enco mill. Would like to move the Phase A Matic static converter from my Wells Index over to it and use the Enco foor awhile to see if I might like it better. Is there a way to determine what goes where on the output side? I cant seem to find markings of any kind.

 

[OccupantRJ]

If there are simply 3 output connections to the motor from the phase convertor, the motor will possibly run backwards. Switching any two of the motor outputs will switch the motor to the opposite direction. Phase a matic website has wiring diagrams.......

 

[rsanter]

If there are simply 3 output connections to the motor from the phase convertor, the motor will possibly run backwards. Switching any two of the motor outputs will switch the motor to the opposite direction. Phase a matic website has wiring diagrams.......

yes.....it is that easy. and be sure you have a good ground

eventually you will want to convert to a VFD

bob

 

[Rixter58]

I wish I had titled this thread "School me on 3 phase". I really dont understand the difference of singe as opposed to 3 phase. Just learned that VFD stands for variable frequency drive so I'm assuming that using one of those adds variable speed to a motor. Do they give you full hp as oppoosed the 1/3 loss of a static converter?

 

[Possum]

First off - enco over wells index????

Secondly, if you have more than one three phase piece of equipment maybe you should think about a rotary phase converter setup to run them both off of. Simple ones are easy to build, self starting ones can be built to from internet plans. I was pull start for a while with my 10hp idler then went the American rotary soft start box route and couldn't be happier. See - http://www.americanrotary.com/

And yes, there are many types of VFD's -by nature they allow you to vary the motor speed and you can get one that has single phase input with three phase output (full hp too).

 

[OccupantRJ]

I wish I had titled this thread "School me on 3 phase". I really dont understand the difference of singe as opposed to 3 phase. Just learned that VFD stands for variable frequency drive so I'm assuming that using one of those adds variable speed to a motor. Do they give you full hp as oppoosed the 1/3 loss of a static converter?

3 phase is 3 hot wires interacting with each other. Single phase is one (120) wire interacting with a neutral, which is acting as a return. 240 volts, which also interacts with each other, is also a form of single phase.
With a VFD, since a 3 phase motor normally runs at 60 cycles a second, by using the VFD to change to 90 cycles, you get a speed increase. A VFD can take single phase and convert it to 3 phase, while also providing speed control.
This is a very simplistic explanation, but further reading will clear things up more for you, or confuse you further.

 

[Rixter58]

Should have clarified that.....the Enco has a smaller footprint and my mill doesnt seem to get used as much more than a glorified drill ppress. R8 is appealing over kwik switch as well.

 

[brucer]

I used a GE vat20 (fm50) vfd for my bridgeport, I wouldnt have it any other way..
you have no power loss and a vfd is cheaper..
plus my bridgeport was an old step pulley mill, now I have pretty much infinite rpm settings..

I also mounted a remote control box with emergency stop that switches off all power to the vfd enclosure, has a rev/off/fwd switch and a spindle stop switch..
works great, updates an old step pulley mill and makes it a little more user friendly.

 

[Possum]

It is cheaper; on one low hp machine. They are the cats pajamas for sure, but if you have several pieces of equipment and they get much over 1-2 hp then buying multiples gets costly. I bought the new American rotary digital start box, a used 10 hp idler, a craigslist three phase panel all for about $400 bucks. Add some conduit and wire and feed it to all your machines. Trying buying a good single to three phase VFD for one 5hp machine with that. It runs a 7.5 hp non clutch style lathe (modern 15" Leblond regal) great. That being said if you only have one three phase machine and its a 2 hp knee mill, the VFD is the way to go. If you have two mills and a penchant for equipment...

 

[Norcal]

VFD's are inexpensive for 3 HP & less after that things change a bunch, w/ 1 HP & less one can get them w/ 120 volts input, 240 volt 3Ø output. Above that, it's 240V 1Ø in & 240V 3Ø out but if one has a 200 or 208V motor most modern VFD's have the option of adjusting the output voltage to 208V.

A static converter just starts a 3Ø motor, but during operation it is single phasing, one loses 1/3 of the rated HP in the process.

 

[OccupantRJ]

Talk about perfect timing for a thread! My wife and I went to my son's house today, and under his carport were 6, yes, 6, Reliance GP2000 VFD's stacked up that his company gave to him on a surplus warehouse cleanup. I of course, ended up with a free one. I already had built my own self start rotary phase converter and had it waiting in the wings, but hey, who turns down a free VFD? I might use it on my 20 inch woodcutting bandsaw, which is so fast it's scary, to tone it down a little.