Wide belt phase convertor

[Kevin Jenness]

Rollie, is that correct? I have several customers running entire shops full of 3-phase industrial equipment off static phase converters.

Erik

Yes, that is true. Ok for lightly loaded motors like my 3hp slot mortiser, but it would be self-defeating to run something like a widebelt off a static phase converter.

It's easy to set up a rotary phase converter with a surplus 3 phase motor. I have about $400 in my 10hp rig. It makes sense for multiple machines that don't require adjustable speed. I have vfds on my lathe, edge sander and exhaust fan where the speed control is useful or necessary, but my slider and planer run off the rpc. Large vfds sem to be very expensive relative to rpcs.

[Erik Loza]

It's true. Those machines are running hot and at ~2/3 power.

Maybe I'm confusing Phase Perfect with a static phase converter? Are they different things?

Erik

[Mitch schiffer]

Maybe I'm confusing Phase Perfect with a static phase converter? Are they different things?

Erik

Yes a static phase convertor is different then a phase perfect. The phase perfect is a digital phase convertor that work somewhat similar to a vfd.

[Kevin Jenness]

I guess you could call Phase Perfect products "static" in the sense that they don't rely on a rotating coil to generate three phase power, but what is generally referred to as a static phase converter is basically a box of capacitors and switches to get a 3 phase motor turning over at which point it runs off off single phase power. Very different animals. Phase Perfect supplies well modulated three phase power that meshes well with electronic controls as on a cnc machine. Rpcs work fine with basic machinery.

[Erik Loza]

I guess you could call Phase Perfect products "static" in the sense that they don't rely on a rotating coil to generate three phase power, but what is generally referred to as a static phase converter is basically a box of capacitors and switches to get a 3 phase motor turning over at which point it runs off off single phase power. Very different animals. Phase Perfect supplies well modulated three phase power that meshes well with electronic controls as on a cnc machine. Rpcs work fine with basic machinery.

Ahh, I see. I always lumped anything that was solid-state into "static" but seems like that's not necessarily the case and perhaps I need to be more careful with how I distinguish them. Thanks for the clarification. For the record, anything I said above was strictly relevant to Phase Perfects.

Erik

[Alan Lightstone]

I can't speak to any experience with static phase converters or VFDs as such, but I can highly recommend a Phase Perfect. I have several digital readout 3-phase machines in my shop (Felder planer, Grizzly wide belt sander), and the Phase Perfect just works. Period. No issues whatsoever. Considering the insane cost that my utility quoted me for sending 3-phase to my workshop, I'm thrilled that I bought one. Pricey, but great.

[Jeff Roltgen]

Key difference between "static" and "solid state" AKA "digital phase converter". Simplest way to put it:
Static "phase converter" is not doing anything other than providing a short term, 3rd leg to kick the motor up into rotation, by way of a few capacitors. In a moment or two, the capacitors are discharged, and all that's left are the first two legs keeping it in rotation. You only have power to the third leg to initiate rotation, then it's spent.
This is why you need to very carefully think the process through. I am using a static convertor on a 5HP dust collector, which is technically downrated by 1/3 to about 3.3HP. No big deal, as their is no "load" to speak of, and the beast effortlessly pulls dust chips for hours. However, a planer or sander require full resources be available through the milling processes, and would likely stutter/falter if not given that 3rd leg for the duration of run time/processing.

Kevin - how did you balance out the 3rd leg voltage on a surplus motor? You have experience/knowledge to put the capacitor arrays together? That's a very valuable skill. None of my local electricians wanted to tackle that process.

Had to sell my old 40HP, as it was pumping that 3rd leg out at a hot 270V. Didn't bother my 20hp sander, as it has a pretty unsophisticated set of controls, and is a brute of a machine. However, would have voided the warranty on a new $13k shaper with more sophisticated (sensitive) controls, so I ended up going with the Phase Perfect.

[Kevin Jenness]

Kevin - how did you balance out the 3rd leg voltage on a surplus motor? You have experience/knowledge to put the capacitor arrays together? That's a very valuable skill. None of my local electricians wanted to tackle that process.

I didn't. I have a setup from http://www.wnysupply.com/index.html, basically a static convertor to get the "generator" motor spinning. I did check the third leg voltage when I set it up but have forgotten the value other than it was not grossly different from the other two. I am running an old planer and a sliding table saw off it with simple magnetic controls. In your situation I would need a more balanced three phase supply. My cnc router runs on 110 v single phase so no worries there.

[Erik Loza]

I can't speak to any experience with static phase converters or VFDs as such, but I can highly recommend a Phase Perfect. I have several digital readout 3-phase machines in my shop (Felder planer, Grizzly wide belt sander), and the Phase Perfect just works. Period. No issues whatsoever. Considering the insane cost that my utility quoted me for sending 3-phase to my workshop, I'm thrilled that I bought one. Pricey, but great.

+1 for Phase Perfect. I've got several shops using them and zero issues I hear of. Not cheap, but a lot cheaper than bringing in three-phase. This being said, if the machinery was just old iron without onboard electronics, I would probably go with a rotary like Kay or American, for budget reasons.

Erik

[Scott T Smith]

I purchased a scm wide belt about a year ago now and its been in storage since I picked it up. I had intended on getting 3 phase power in my new shop but the price for the electrical company and my electrician was 114k just to get the panel installed. My next idea was a rotary phase convertor. I called up American rotary and the price for the convertor they recommended was around 8k. I'm now thinking about a large vfd since I have several other vfds in my shop and they work well. The wide belt has a 18hp main motor and 2 separate 1 hp motors for the feed belt and table height adjustment. Has anyone used a vfd for a wide belt or possibly a digital phase convertor like the phase perfect?

Mark, I used to run a 37" EMC WBS off of a Phase-a-matic 30hp RPC. The EMC was around 22hp as I recall. My only problem was that the time it took to spin the WBS up to speed was greater than the current inrush timer, and it would usually spin up around 75% of the way and the timer would kick out - causing the machine to stop.

I solved that problem by keeping my fingers poised over the start switches and hitting them again immediately after the timer kicked out - and before the motor spun all the way back down. Once started it worked fine.

If I'd had a 40hp RPC, I'm sure that this would not have been a problem.

If you have the coin, the Phase Perfect digital system is reputed to be the best option for a phase converter. I run all of my larger equipment off of a generator, and the smaller equipment off of the RPC.

Best of success to you.

Scott