Any such thing as an "inexpensive" Phase Inverter? Gotta be safe too.

I am trying to convert a 7.5hp 3-ph electric motor to a 1-ph application without going broke...

 

yes there is. but they are only part ime units and big $$$$$$$ to run a 7-10 hp motor you will need a big one they run about 900.00 plus shipping. maybe just swap the motor or have it rewound for 1 phase.

 

Try these folks I installed one of their's in my buddy's machine shop.
www.deselectric.com

 

Try one of these for info and a source:
http://www.phaseconverter.com/rotary-converter.sizing/
http://www.metalwebnews.com/electric.html
http://www.andersonconverters.com/

I have the same problem with a 7.5HP lathe motor. I would need at least a 10HP rotary phase converter. The panel runs about $250 from Anderson and I would need to visit an industrial surplus center to get a 3Ø motor but they are relatively cheap used. You need a rotary converter not a static converter.

Rewinding would require new reversing controls etc which can be big $$.

 

a few months back i got a 10HP converter from anderson the complete unit shipped for around $750 if i remeber right. Easy to hook up and runs great.

 

Ha Stoner

I went through this same problem. My electric company will not bring 3PH out to my shop do to location. I am running half of my machines through a Roto-Phase. I have a 7 HP unit that has been in service now 3 years. I had a few problems on start but vendor made it good. They offer a 3 year warranty. Comes with motor and contol panel. Company called Electrophase out of Anderson SC. Cost ran $500.00 with free shipping. Hope this helps.

 

OK, what do ya'll think of this:

http://cgi.ebay.com/1-PHASE-ELECTRIC...QQcmdZViewItem

 

Ahhhh, -no... Get the right design and the right parts in a proven package from someone like Anderson. The amount of power involved in a running a converter is NOT something to play around with and take chances like that. You may end up letting the smoke out of the motor or home built phase converter and burning down your home or shop. That would really ruin your day because the insurance company may just look at it and say "no coverage"... A company like Anderson has insurance to cover them for things like burning down a home or shop.

 

All a rotary converter is is a three phase motor being run on a static converter. The 220 single phase is run through the 3 phase motor, yielding true 3 phase power. I built one and it worked fine; never got hot or seemed to pose any fire hazard. I found plans free online. But any contraption built using substandard materials, shoddy workmanship, and ignoring safety guidelines is a hazard, as Torque1st pointed out.

 

The info that guy is trying to sell on EBay is available on the web for free. Google for phase converter and you will find it. Pick the site you understand the best. If you are not comfortable working with electricity and the instructions don't make sense to you, don't do it, buy one and have it installed.

 

It seems there is a lot of "info" for sale on eBay that is avaialable for free.

I have designed more electrical contraptions than most and built a few but I will still buy the panel from someone like Anderson and hook up my own 3Ø motor to it. That way if the unit burns the house down or electrocutes someone I am covered. Used 3Ø motors are available from electrical equipment salvage companies and it is a lot cheaper to pick one of those up locally than it is to pay for a new motor and ship the heavy beast.

 

Torque 1st - a lot to be said for purchase. Some for the reasons given. Other reason I've run into is, unless I have a good inexpensive source of parts and all the tooling needed to do a neat, professional job it is often cheaper, and almost always quicker to purchase. You are very correct on shipping of the motor.

 

Yes, I know what you mean about parts and tools etc.

Most commercial units have ratings and instructions that can be shown to an inspector or the fire marshal. They also usually have UL or CSA recognition which will help greatly in case of a mishap.

(Rant on) I always look for a CSA (Canadian) listing since I think those standards are MUCH better than UL. I have seen tooooo many things that were UL listed that were a joke tho. UL standards themselves are a joke. Been there done that. (Rant off)

 

I have many three phase machines. Before I got real three phase power in my buildding I bought an Arco 10hp converter off of ebay for $400. If I had it to do over again I would go the cheep route and just use a 10hp three phase motor and a rope. The kits for a 10hp converter can be bought in the $200-$300 range but why bother. All the kits do is to start the three phase idler motor and then balance the voltage between the three legs of the 3ph power once started. Unless you are running sensitive CNC equipment you probably don't need this. Find a three phase motor for the idler. These are cheep. Try a motor shop, auction, or junk yard. Hook up 220v single phase, two lines in to the idler motor and hook up the three legs out to your 3 ph machine and you are in business. Oh yea, you have to get the three phase idler motor spinning. Simple way is to wind a rope around a pulley on the 3ph motor shaft and start it like a lawn mower. Once it's spinning you have three phase power. Some folks use a small 1/2hp or so single phase motor to spin up the three phase idler rather than a rope. The small single phase motor is connected to the 3ph idler with a v belt and then the belt disconnected by pivoting the single phase motor off line, once the idler is running. Simple and cheep. You can get set up for the cost of the 3ph idler motor, $10-$50. My local machinist has been running his shop with this set up for 25+ years, Bridgepost, three laths, bandsaw, ect.