Phase Converters

[downsizingnow48]

The specs say it is good for 2 hp at 240v and that is what I am doing.

 

[Budweiser John]

Here is a picture of my three phase set up. The converter is a RotoPhase listed for 20Hp max but will operate up to 60HP total load.
This setup has been in service for over 30 years and works flawlessly.

 

[Mendonsy]

YES, many work very nicely on single phase, some won't BUT YOU HAVE TO DERATE THEM. Call AC-TECH (Lenze) or A&B support if you don't believe me.

That is true for any drive designed for 3 phase input, but there are also many drives out there designed specifically to be a phase converter. Here are a few of them. phase-converter-drive

 

[Industrial Toys]

I was talking VFDs specifically.

 

[Erik M]

Love the Art Deco disconnects.

 

[downsizingnow48]

My KB Electronics KBAC 27 is a variable frequency drive (VFD). The complete description from the manufacturer is at the link below.

KBAC-27D Black (952) AC Drives, Nema 4x Inverter - KB-Controls.com, Your online Shopping for AC & DC Controls & Drives

In addition to variable speed, it has a jumper that doubles the max output frequency (60 or 120). I use the 120 setting so my 2hp 3ph 1725rpm motor runs at 0-3450rpm approx. That gives a very workable range of belt speeds suited to grinder belts with different grits from 36 to 400.

It requires single phase input.

They make another model, KBAC 29, that requires three phase input. See link below.

KBAC-29 Black (9528) AC Drives, Nema 4x Inverter - KB-Controls.com, Your online Shopping for AC & DC Controls & Drives

 

[GeneV]

I had this debate a few years ago when I moved my shop out of a facility that had 3p. I looked into vfd's but decided rotary phase for a knee mill and toolroom lathe. I went with American Rotary, got their AD20, 20hp converter. It was around $2100 total with their breakers, floor mount kit, and shipping. Then there was subpanels to install and wiring to fan out to the machines.

 

[grsthegreat]

ive installed many phase converters for people over the years. From $50 craigslist used rotary units to $6,000 electronic models used in center pivot systems . The units i see are usually far larger than ever needed to run a HOME shop environment as they came from machine shops and are being used in a home shop "one tool at a time". My biggest issue with rotary units is there so noisy. VFD are so nice and quiet.

Mind you most machine shops are always noisy, but home shops are not. I always place a disconnect next to the drive unit so its easy to shut down when equipment is not in operation. One customer had me locate shut off switches daisy chained to all his equipment for ease of use.

Most units ive installed in the rotary style are so old i cant even find info or schematics on them any wheres. Some from companies that have been out of business for many years. But the things still work great. Very few parts to go out. VFD are very touchy at times. Have to install surge suppression and lightning strike protection at times. Rotary units can be repaired easily at motor shop if necessary...not so with VFD units. there like computers . Kinda throw away if theres a problem.

 

[texasranger556]

YES, many work very nicely on single phase, some won't BUT YOU HAVE TO DERATE THEM. Call AC-TECH (Lenze) or A&B support if you don't believe me.

I might be staying the obvious here, but it is important to differentiate what is being de-rated.

With a static converter you have to derate the motor being driven. With a VFD you have to derate the 3 phase rating of the VFD itself when feeding it single phase power. So you can get full capacity of the 3 phase motor being driven by oversizing the VFD accordingly. For example I have a 10 HP rated VFD running the 5 HP spindle on my mill, which may still be a little undersized but plenty for my needs.

Several years ago when I was looking for a VFD I didn't see many VFDs with a single phase rating once you get over 2 HP. Maybe that has changed.

 

[chriswheeler]

I started out with the capacitor starting phase converter ( phase O mattic ) at first on my 3 phase 2 hp. drive motor. Didn't like it much, didn't do well under full loads or heavy cutting conditions. I bought a electronic VFD phase converter with a soft start and have been happy every since. Not only do I have a true 3 phase power supply from single phase, but every speed on the step pully has a full range of speeds in that range. In the middle of a cut, you can fine tune the RPM to get rid of chatter for a nicer cut and finish. As a cutter gets a little dull. that can be adjusted for as well. Not cheap by any means, best place to buy, eBay. Mine was from a local dealer for $500, not the cheapest thing out there, but a true 3 phase.
Chris