Who makes the best rotary phase converter?

[DF-ENTERPRISES]

I have a American Rotary for my cnc bridgeport and it is not very reliable. Anybody have a RPC that they have good luck with and would reccomend?

Thanks

Derrick

[jdr]

Phase Perfect by American Rotary is still the best.

You might ask American Rotary to help pin down your problems.

[DF-ENTERPRISES]

I was looking at a phase a matic with a voltage stabilizer?
Any comments?

[ckirchen]

What's wrong with your American Rotary?

I have a 10HP and a 40HP. The 10HP is 2.5 years old and has been quite reliable. Voltage balance is good whenever I check it with a voltmeter and it makes no more noise than the day I installed it. The 40HP is less than a month old, but from the install and use so far, it seems just like the 10HP, only larger.

I have recommended them to a few people.

Chris Kirchen

[DF-ENTERPRISES]

Well when I first bought it and installed it there was a large voltage imbalance between the three legs. My cnc Bridgeport would fault out. So I sent it back and they fixed it. Now my voltage is balanced nicely under no load but when I start my machine the voltage drops down to 130 volts between legs t-2 and t-3. and my machine faults out. After that I threw my hands in the air. I need to run parts not diognose voltage problems. Sorry just a little frustrated. I'm running a 5hp RPC by the way.

Thanks.

[ckirchen]

Hmmm. Not exactly sure what could be causing the voltage to drop out like that. Assuming that the RPC is working, there are a few things to check:

How big is the machine? Could the RPC be undersized? My 40HP unit is running a 20HP lathe. The rule of thumb for CNC applications is 2 times the spindle HP.

Also, T3 is usually the manufactured (or wild) leg, it should not be used to power the computer side of the CNC. You might have to trace wires from the machine's input breaker to the computer power supply to be sure.

RPCs work be take single phase power and 'repurposing' (for lack of a better word, I am not an electrician) it into three phase. The RPC cannot create power; if the available single phase power is too low, it will not have enough power to make proper three phase. kVA_in = kVA_out (minus losses).

Attach a clamp ammeter onto one of the single phase input lines. Looking on American Rotary's website, that 5HP unit is rated for 8 amps at 5% voltage balance (that means is your CNC is drawing 8 amps in three phase power, the voltage balance will be within 5%). 8 amps three phase is approximately 14 amps single phase (current_three_phase = 1.73 * current_single_phase), so if you see more than 14 amps on the ammeter, the RPC is becoming unbalanced due to excessive load.

Chris Kirchen

[DF-ENTERPRISES]

I checked voltage on the input lines (L1 & L2) and they were at 243V with no load and dropped to 227V at start up so thats not a big deal. I talked to american rotary today and they suggested running another 5hp RPC paralell with the one I have. I also could run 1 single 10 hp RPC to make sure I have plenty of power under anyload or of course theres Phase perfect but thats a little pricey. Its only a 2hp spindle motor but with a max RPm of 4200 which has a alot more voltage draw. On the mfg plate on the spindle motor shows 7 amps for the max. Anyways I want to get some more input from other manufactures before I dig into my wallet again.

Thanks alot for your input

[lex69]

We got the phase converter for our pump at Temco. http://www.phaseconverter.com/ It helps that the phase converter is more HP than the equioment it is converting for. Our pump is 15HP but the phase converter is 20HP. Good Luck!

[Farmers Machine]

You can hook up 100 5 horsepower units and still only run 3 horsepower. You have to have one unit larger than any motor you are making power for so that it has enough steel in the armeture to generate the electromagnetic force or energy to power the smaller motor. you can hook up all of the little motors you want, the more the better. if you are getting low amperage on the artificial leg add some motor run capicators from either of the single phase lines to the artifical leg. on the converters I build from scratch to use on remote jobsites the rule of thumb is 10 MFD per amp of under balance when loaded. Hook up a line reactor between the rotary and the CNC to protect the CNC control, and you should be off and running.
good luck
the Farmer.

[cnctech101]

I have had phase a matic 10HP and now I use a 30HP unit with stabilizer purchased on ebay like new for 1,300.00 amps idle is 12 amps running cnc mill 3 hp fanuc pulls 16amps super quite I had a friends super loud & pulled way to many amps at start up popped 60amp break
I run phase a matic on same breaker no prob

[ShadeTreeWelder]

I have an Electram 5 Hp unit to run my lathe, bridgeport and surface grinder.

I have been very happy with it, I added a pilot light for a visual confirmation
that it is on 'cause the damn thing is too quiet....

[DF-ENTERPRISES]

Hi guys. Thanks for all the imput. I did end up trading my 5hp American Rotary RPC in for a Remco heavy duty7.5 hp cnc RPC. Check them out at http://phaseconverterspecialist.com/
They actually design and build many different types and they can answer questions about installation and voltages, amps etc...Plus they are a local company in my area. I also installed a single phase buck boost transformer to step down my voltage from 242 to 230.
Now my spindle starts at any rpm with no errors.