Kinetix drives powered by rotary phase converter

Has anyone had experience with powering larger A-B Kinetix drives (or equivalent) from a rotary phase converter? I am building a machine with seven axes of 2198-H040-ERS and 2198-H070-ERS drives. I need to do the build and startup offsite where there is no 3-phase power.

I am hoping the power quality from a phase converter will be good enough to keep the drives happy. I'd hate to invest a couple thousand dollars only to find out it won't work.

Thanks.

A couple thousand should rent a three phase generator of the size you'll need.

I'll be testing and developing over a period of 4 months before delivering the machine so renting probably isn't an option.

Have you actually priced a rotary phase converter, isolation transformer, and line reactor? And considered the cost of the servo amp when you blow up the capacitors hooked to the wild leg? Scares me and I'm fearless...

No. Now you have me scared. I didn't realize there was more at risk than just the possibility of the drives being particular about the power quality and throwing faults. Are you suggesting this is a bad idea and I should just go with a generator?

My strongest suggestion would be to temporarily rent a facility with three phase utility power. Most industrial installations in America will utilize 480v three phase, although I suppose it's possible your customer only has 208v.
In a previous life I worked extensively in agricultural automation and have had nothing but bad experiences with powering drives from generators and phase convertors. Some of that is no doubt due to poor maintenance, but the best results I've seen were extremely reduced service life.
I believe user Bering C. Sparky works on a ship, perhaps he has more relevant experience in a well-maintained generator driven environment.
If each axis is small, you could use single phase servo amps...

Thank you AutoMax. Your advice and experience are exactly what I was hoping for. But it does leave me with a dilemma because I'm in a rural area with few industrial spaces and ever fewer with 3-phase power.
Do you think a few hundred hours of runtime while starting up and testing will be detrimental to the drives, or would that mainly be the case if this was the permanent power source?

Well, I can think of one instance where I had a mean time between failure on a drive of three weeks. It was a center-pivot irrigation system with a generator from the same manufacturer. We kept sending the drives back and the manufacturer kept saying it was lightning damage. Then we hit a multi-week dry spell (no lightning) and the drive failed again. We installed an isolation transformer and line reactor and managed to get the drive to the point it only failed once a season. This went on for a couple years until the client got fed up and we installed a mechanical speed controller and across the line starter.
I'm certain it's possible you can get a generator installation to work, but I'd definitely start with a generator that had all solid state controls (like a Gillette). With a lot of generators the throttle is mechanically controlled by a voltage and (maybe) frequency sensor. As the load increases and decreases you see wild swings in voltage, current, and frequency.
Have you considered using a servo that allows you to directly feed the DC bus? Some Kinetix have that option, and I've done it with Siemens and Yaskawa servos. A generator with a rectifier and solid state voltage control might be the safest.
Maybe you'd be fine using the generator, but it seems like a mighty big risk...

I have renewed my effort to find a rental space with 3-phase power. It seems like I'm better off making a longer drive in order to avoid the problems you describe.

Thank you for your input.

An RPC typically uses a capacitor to smooth out the unbalanced voltages on the manufactured leg when feeding a motor, but as a piece of rotating machinery, the motor actually helps to make that even better. But remember, the other two legs are 180 degrees from each other, not 120 degrees like on a 3 phase system, then the manufactured 3rd phase is somewhere in between two of them.


So when feeding a bridge rectifier, like on the front-end of a VFD or Servo Amplifier, the diode pulsing that takes place in the bridge will not be as evenly balanced and also because diodes fed from capacitors see the capacitor almost as an infinite bus, the net result is that the DC bus on the other side of the rectifier will have considerably more ripple, and that's what's bad for the drive. The DC bus smoothing capacitors will run a lot hotter and the transistors for the output don't like rippled DC feeding them.

So as I see it you have two choices: you can over size the kinetics units to end up with more DC bus capacitors to smooth out that ripple (just as you would if feeding it with single phase power), or instead of a cheaper RPC you actually buy an M-G set, where a single phase motor drives a true 3 phase generator. The output of that will be a true 3 phase sine wave. That's the way I would go itf this is temporary (and especially if you have already bought the Kinetix).

Now if you have already bought the RPC as well, then you may as well try it. I would put a Line reactor ahead of the Kinetix feed to help a little more with balancing the phases, but in Kinetix, if it detects excess DC bus ripple, it will trip off line and indicate a Phase Loss (that's actually how it detects a phase loss). So you will not likely harm the drives, but you may not be able to run them.

Seriously rent a small (whatever size you need) 3 phase genset. Or look for eBay deals. You can actually find so e pretty good deals on eBay for 3ph generators.

I wonder how far you might get with a VFD that will take single phase input? You would definitely want a line reactor to clean things up a bit.
I have a similar situation headed my way in the future.
(No Question that a Gen-Set will be the best solution short of getting 3 phase to begin with )

Seems like motor-generator sets are a lot harder to find. Do any of the rotary phase converter companies offer them? My searches don't find much. Interestingly a couple of the rotary phase converters claim to have true 3-phase output at 120 degrees. Are they doing something special, or is that just a marketing angle?

They may be fine with no load but when you start applying impedance to the system it will suffer from the same problem.