school me about phase converters
- Thread starter t100
- Start date
Glacial_Speed
Well-known member
Another option is to look into variable frequency drives or VFDs.
How much horsepower are you talking about for these grinders? Because like most everything, more horsepower means more cash.
And are you planning on running several three phase machines at once or just one at a time?
How much horsepower are you talking about for these grinders? Because like most everything, more horsepower means more cash.
And are you planning on running several three phase machines at once or just one at a time?
this beast for $175, 1hp, 3 phase, 230v, 1800RPM, 4.4 amps
another is 480v so that's out of my range.
stonesfan68
Well-known member
These guys are really good. Call up their sales department and they can get you sorted out.
http://www.phaseperfect.com/index.htm
We've used them a couple of times for some 15-20HP conversions and the equipment worked flawlessly.
http://www.phaseperfect.com/index.htm
We've used them a couple of times for some 15-20HP conversions and the equipment worked flawlessly.
Glacial_Speed
Well-known member
I assume you're buying one instead of building a RPC, since some people like building rotary phase converters out of old motors and parts, but that's an interest I don't have.
Rotary phase converters usually make more sense for larger amounts of HP, but a grinder if the grinder is 1 hp I don't think I would go the RPC route. I seem to recall the rule of thumb was 3 hp and over was cheaper RPC, and under 3 was VFD.
There are rotary phase converters and static phase converters. Statics have a bad reputation for putting lots of stress on motors and burning them out, and they can only put out 2/3 the rated power of what you're running since they aren't using all the phases. However you will have people saying that they've had no problems running statics for years.
Rotary phase converters are usually looked upon as a more proper way of doing conversion than statics.
Some people buy larger phase converters and then run several machines off one RPC.
A variable frequency drive in the 1 hp size is about $150 . VFDs are popular with people running mills and drills because of the variable speed control they allow. Several discussions on places like CNC zone or practical machinist on how to use them, and lots of youtube videos.
For a grinder, I'd use a VFD to get the speed control.
They can be found at factorymation and other places, ...gotta run.
Rotary phase converters usually make more sense for larger amounts of HP, but a grinder if the grinder is 1 hp I don't think I would go the RPC route. I seem to recall the rule of thumb was 3 hp and over was cheaper RPC, and under 3 was VFD.
There are rotary phase converters and static phase converters. Statics have a bad reputation for putting lots of stress on motors and burning them out, and they can only put out 2/3 the rated power of what you're running since they aren't using all the phases. However you will have people saying that they've had no problems running statics for years.
Rotary phase converters are usually looked upon as a more proper way of doing conversion than statics.
Some people buy larger phase converters and then run several machines off one RPC.
A variable frequency drive in the 1 hp size is about $150 . VFDs are popular with people running mills and drills because of the variable speed control they allow. Several discussions on places like CNC zone or practical machinist on how to use them, and lots of youtube videos.
For a grinder, I'd use a VFD to get the speed control.
They can be found at factorymation and other places, ...gotta run.
Good write-up. Do you want to build your own RPC? If so then I can direct you to plans that worked for me.
lg
no neat sig line
camarotoolman
Banned
@ woodworking talk foreum they discuss this alot.
badgcoupe
Well-known member
Just for my own knowledge how do you know what size (HP) phase converter to get? Do you just match the power of the converter to thing it's powering? Thanks!
The grinder in the pix would probably work OK with low level (1-3hp) version static converter. I have a very old Index Machine Model 55 mill running on one since about 1987. It's a hobby machine and the converter came with it. I bought a Monarch 12X36 lathe (made in 1941) and it has a 3hp motor, belt drive and I reverse engineered the static converter on the mill and have been running the lathe with it, again as hobby, not any type production since about 1989.
Never had any problems with them.
I've acquired a offshore 3 axis CNC mill and did get a 5hp rotary for it since I was told the computer portion and servo drive would not function with a simple static.
Never had any problems with them.
I've acquired a offshore 3 axis CNC mill and did get a 5hp rotary for it since I was told the computer portion and servo drive would not function with a simple static.
theoldwizard1
Well-known member
I agree 100% !
I would only add, that if you are going to buy a VFD, buy one bigger than you need today. You never know when you are going to tun across a smokin' hot deal on a 3hp mill or lathe !
bsaint
Well-known member
I think some people forget that a VFD is a square wave not a sinusoidal wave. Make sure your motor can handle a square wave.
bad_idea
Well-known member
hey larry,
I am interested in those plans for a rotary. Mind posting up that link? Thanks.
I am interested in those plans for a rotary. Mind posting up that link? Thanks.
jabberwoki
Well-known member
Dude love your new???? grinder.
I`m just finishing up the 3 phase set up for my shop this weekend got most of the bits of craigslist.
Look at phoenix phase converters.
Once you get your set up installed there are so many fantastic old quality 3 phase machines out there for not much $.
I`m just finishing up the 3 phase set up for my shop this weekend got most of the bits of craigslist.
Look at phoenix phase converters.
Once you get your set up installed there are so many fantastic old quality 3 phase machines out there for not much $.
http://www.metalwebnews.com/howto/ph-conv/ph-conv.html
Be aware that on the linked document you have to click on the blue "figure" words to get the picture or schematic to come up. I built the 5hp one 10+ years ago and it is still humming along. I used the caps recommended and the balance was good. I changed the control circuit to 24vdc as I had all the relays in 24vdc.
lg
no neat sig line
Primered Thunder
Banned
Running a late 40's bridgeport mill off a VFD in my home shop ... PM me with any questions.
Strouty
Well-known member
If you go with a VFD, you should be able to control the speed of the motor as well. This would be cool on a grinder, especially a bad boy like the one in the picture.