Replies

1. 
   [email protected] | Mar 14, 2008 05:44am | #1

   Yes they work well, if sized correctly.  They have been around for ages, and the commercial units will deliver what they say. 

   The electrical engineers I work with all say to get a variable frequency drive instead though.  Apparently the new ones are very reliable, and don't have the torque drop off issues the earlier generations did.  Being solid state devices, they are more efficient.  And, you get the bonus of being able to control the speed of the equipment. 

   A word of warning though, if you run a motor under load at reduced speed it may over heat, because the cooling fan is run by the motor so it isn't running fast enough to move enough air for cooling.  The solution to that is to just mount up a fan on the end of the motor to keep the motor cooled down. 

   The difference is the rotary can run a shop full of machines, and a vfd is dedicated to one machine. 

2. 
   chairmannz | Mar 14, 2008 12:21pm | #2

   Hello iannlb,

   I use a rotery converter and have 2 machines running on it no problem.
   I can run up to 5.5 KW.
   Cheerio Bernhard.

3. 
   RickL | Mar 14, 2008 02:49pm | #3

   A rotary converter, VFD, and http://www.phaseperfect.com will give full power to a 5 hp motor.  The other thing to consider is a static will give 2/3's power to a 5 hp and that rings  in at 3 hp which will cut anything you need and was the standard hp you  could only get for years and no one ever lacked power with a 3 hp. There are better balanced static converters available.  http://www.waterfront-woods.com/