phase converter for miller cp-300

[CoCowboy30]

This machine produces 300 amperes @ 100% duty cycle.
I need to know what size of converter I need and if anyone has recomendations of manufacurers and best price on phase converters.
thx

[Mike W]

You need to know what the input power spec is. You can built your own rotary type converter with a 3 phase motor hooked to a single phase one. Do a search, the info shouldn't be too hard to find.

[CoCowboy30]

input power specs for this model are as follows:
Three-Phase;200,220,230,380,415,460,520,or 575 voltsAC; 50/60 Hz
I did a search on building my own three phase converter and found a lot of useful info and am considering building one, depending on the cost to just buy one. I seen price ranges from $400-$1500. I need more info as to the size I need and a good brand for the price.
thx

[Fla Jim]

What are the input amps? you need that to size a phase converter.
I Built one for the "Magic Garage". I use it for my South Bend lathe. I used a 5 hp motor for an idler. I'm running a 1hp 230 volt 3 phase motor on the lathe. I sized it large so in the future if I ever get a three phase Bridgeport.

[BSOK]

Here is a Phase converter my brother built for our home shop.
Small motor brings big motor up to speed and then the belt is removed via the small motor is on a hinge. The big motor is connected to a 40amp disconnect switch 220v, providing enough power to keep the motor running. The larger motor creates the third leg of power. Then a 3 phase plug is connected as the output. If you need more info I can explain futher and send more pics. We use it to run a stock feeder on a table saw and a powermatic 24" planer.

Happy holidays.

[Fla Jim]

I start my idler motor with capacitors. I have a time delay relay that energizes a contactor that puts capacitors in the third led for.1 second, long enough to start the idler motor rotating. Then drops out of the circuit. I also put a phase monitor in the control circuit that shuts everything down if I loose a phase. I also balanced my volts and amps between phases with capacitors between a and c phase, and between b and c phase.
This is the outside of the enclosure.

[Fla Jim]

This is the inside with the controls, the big start caps in the back, small run caps in the front.
You need about a 100mfd's per horse power to start a motor. I added a little more for a fudge factor.

[Ed in Ga]

Fla Jim,
I use about the same setup to run a 5hp lathe and a 1.5 hp B/P. Don't remember the total amp draw for the two but I think it is well under the requirements of a 300 amp welder. Most rotary converters are rated for hp motors they can run not amp output. With the price of used 3-phase welders I've wondered about this before but never followed up. Be interesting to hear from someone who has tried this.
Ed

[Fla Jim]

We need to find out the input amps @ 230 volts

[Ed in Ga]

Fla Jim,
CP-302 which should be comparable is 33 amps at 230v 3-phase.
Ed

[Fla Jim]

For 33 amps I think you would need a 10Hp motor for an idler.

[CoCowboy30]

ok here is the info I have.
Input amperes at rated output:
38 A At 200 V,34.5 A At 220 V, 33 A At 230 V,20 A At 380 V, 18.3 A At 415 V, 16.5 A At 460 V, 14.6 A At 520 V, 13.2 a At 575 V.
Also I would like to know about the cost for materials to put this converter together coming off of a 220 V line.
thx

[BSOK]

FLA Jim

Very nice set-up you have constructed. How often do you use your converter? About how much do you have tied up in the parts?

We where lucky to have most of the parts at the house and have about $50.00 in misc materials. We had the small motor from another piece of machinery and where lucky to score the large 3 phase motor from our other brother who works at a golf course. The motor was running an irrigation pump that seized. We where not sure if it would run but after a few hours of cleaning and removing the old pump housing and mounting flange we where surprised. Ours gets used 5 or six times a month and serves us well.

Happy Holidays.

[cutter]

Originally posted by CoCowboy30
ok here is the info I have.
Input amperes at rated output:
38 A At 200 V,34.5 A At 220 V, 33 A At 230 V,20 A At 380 V, 18.3 A At 415 V, 16.5 A At 460 V, 14.6 A At 520 V, 13.2 a At 575 V.
Also I would like to know about the cost for materials to put this converter together coming off of a 220 V line.
thx

Cowboy,

I have been meaning to someday get around to building a rotary converter myself. I did get around to a little research; here is an article I found on the Old WoodWorking Machinery FAQ that might help you, followed by a link to a pdf file with more technical informatin that you likely will need..

[http://home.att.net/~waterfront-wood...econverter.htm

and the data (let me know if you have trouble following all of the math - it will make me feel better .)

http://files.owwm.com/PDF/FAQ/PhaseConverters.pdf

[axehind]

Maybe these will help you figure out what HP rotory phase converter you need.

http://www.roto-master.com/SPECS/index.htm

http://www.gwm4-3phase.com/hieff.htm

axehind