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View Full Version : VFD for Single Phase



RobbieKnobbie
04-09-2008, 07:01 PM
They're a little pricey, but this company is selling VFD's for single phase motors.

Looks like they only go up to 1.5 HP, won't work with cap start motors, and have limited starting torque, but if you're looking for speed control and just can't bring yourself to replace your motor, this may be the ticket...

single phase drives (http://www.anaconsystems.com/text/opti_1.html)

CCWKen
04-09-2008, 08:34 PM
Thanks for the link. It's a nice option but for the money, you can convert to a 3-phase motor AND a VFD to get the benefits of better control and smoother operation. I think they'll have to come down in price to compete.

wierdscience
04-09-2008, 08:57 PM
They would only work with spilt phase motors though.

J Tiers
04-09-2008, 09:32 PM
The ACTUAL company is in the UK. As far as I know, Anacon is basically defunct..... The drive shown is obsolete.

http://www.invertek.co.uk/

I have used their 3phase drives, the 460V/480V version (no surprise, my boss is also a rep for them).

Never used the single-phase drives.

As I understand the single phase, they are really only useful on PSC type motors (the ones with a capacitor but no centrifugal start switch). That type is often used in HVAC for blowers, so the applications make sense.

If you tried to use them on what is typically called a "split phase" motor in the US, the centrifugal start switch would cause trouble for you.

RobbieKnobbie
04-09-2008, 10:33 PM
The web site of the (now defunct?) supplier in the US says the drives should not be used with either split phase or capacitor start motors.

I was touring a facility today that was using their single phase drives on little AC gearmotors. He commented that he liked them because they are small, reliable and inexpensive... which I guess is a relative term.

I brought this up not so much because it looked like a good application for HSM'ers - due mostly to the price, but to suggest what technologies may be around the corner.

J Tiers
04-09-2008, 10:36 PM
The web site of the (now defunct?) supplier in the US says the drives should not be used with either split phase or capacitor start motors.


The "split phase" and capacitor start as those terms are use in the US both have switches. The PSC type has the cap, but no switch. Many gearmotors and fan motors are of the PSC type, and would be candidates.

The shaded pole type fan motors can be speed controlled with a resistor or "variac", and need no VFD.