vfd accessory - Electrician Talk - Professional Electrical Contractors Forum

garfield · 07-26-2010, 07:51 PM

I was looking at ebay for a drive to use personally and came across this. Can someone explain. I know the vfd manufacturers sell units to go from single phase to 3 phase or sometimes just recommend derating the unit. I am wanting to hook up a 10 hp 3 phase centrifugal pump on a single phase 240 volt service. http://cgi.ebay.com/Single-Three-Pha...item3caf710056

varmit · 07-26-2010, 08:52 PM

What ever this thing is, it is too small for a 10 HP motor. Most manufacturers make single phase input, 3 phase output drives, but usually only up to 3 to 5 HP. A 10 HP 1PH to 3 PH could be made by some company that I am not aware of, but I would think that it would be very pricey. I would never buy a used drive. You have no idea what problems that you are getting.

I looked this device up on the MFR web site: This is an electronic single to three phase converter for up to 7.5 HP. You would need the next larger size phase converter for a 10 HP motor, AND A 10 HP VFD.

mcclary's electrical · 07-26-2010, 08:56 PM

Quote:

Originally Posted by garfield

I was looking at ebay for a drive to use personally and came across this. Can someone explain. I know the vfd manufacturers sell units to go from single phase to 3 phase or sometimes just recommend derating the unit. I am wanting to hook up a 10 hp 3 phase centrifugal pump on a single phase 240 volt service. http://cgi.ebay.com/Single-Three-Pha...item3caf710056

This is not a drive

garfield · 07-26-2010, 11:02 PM

Thanks for the help. Guess I'm back to making a phase converter myself. I thought this may enable me to buy a normal vfd and use it for my application.

nrp3 · 07-27-2010, 06:31 AM

Call AC Tech, they helped me with that situation. They don't have much on their site about single phase to 3 phase. They will help you over the phone. One of the better customer service experiences I've had.

John Valdes · 07-27-2010, 11:33 AM

Go to www.automationdirect.com and look at AC inverters (VFD's). Making your own phase converter? Why? They are cheap and readily available. That is like saying your going to repair your light bulbs. kidding somewhat.

Every VFD on the market can operate three phase motors from single phase. Most good manufacturers list what can be used in this manner without derating. Usually its about 5 HP where the cutoff is. After that usually its one size bigger. In your case it would be 15 HP.

Check these too. You will have to use a distributor, they will not sell direct like the one I mention in the first sentence of this post.

www.baldor.com
www.yaskawa.com
www.wegelectric.com

garfield · 07-27-2010, 01:50 PM

Thanks for the help. I'll chase it with worldwide.