Which Inverter/Converter?

you want one at least 1/2 hp bigger than your motor

i would go for the rotary one they sell ...then its plug and play for every thing you buy, that is three phase .and can run more than one machine at a time.and will be there for future machine buys....they are noisy though.

statics Ive heard can bite you if you have no electrical knowledge

mines an isomatic rotary D4 5.5 hp .........cost me a lot 4 years ago =A3700 ish ......now =A31321..isomatic guys lost the plot I think ...transwaves rotary converter cheaper and has amp gauge on off switch...so wont recommend isomatic to you.

All the best..mark

First check that your motor runs, or can be run, on 220-240v supply. Some 3-phase motors can only be run on 415v - if that's the case with your motor then your choices are limited. If it can be run on 220v then I'd go for a single to 3-phase inverter VFD every time; you get soft start, easy reverse, and variable speed all in the one package. But make sure the inverter is rated for the power of the motor.

On or around Fri, 18 May 2007 07:54:44 -0500, Mr Crane enlightened us thusly:

as an alternative, consider replacing the motor with a single-phase unit. Unless you're going to use the inverter to give you variable speed as well, of course.

In choosing a motor you want one described as "capacitor start/capacitor run" or "high torque" or suchlike.

My student had a cheap low-torque 1.5HP on it, which wasn't up to it. since replaced with a 2HP high-torque and it'll now run at all the speeds - it's a tad down on power (should be a 3HP) but I mostly only do light work with it anyway - if I was doing serious stuff I could have got a 4HP (3KW) for a few more quids.

got the motor from this lot.

IMHO the transwave unit is OK but struggles to give adaquate phase angle, also is not exactly sophisticated. The modern inverters give true phase angle three phase although a square wave output. They have soft start and are variable frequence, with many many other features, and better yet if you need incerased capacity, they can be run with multiple units with one as a master and several slave units. While the plug on the transwave is a goodish idea, a better one would be fittind a socket outlet and control unit so differant equipment can be plugged in and give variable speed and reverse at the machine.

Isn't there a problem with the power differential between the motor on a large lathe and the fractional hp motor on the suds pump when using an inverter.