Originally Posted by
Stustoys
I wonder it you're confusing your motor with "normal" single speed 240V delta motors. While you've connected your motor in Delta (I believe) its series Delta..i.e. its still wired for 415V.* Both your "star connected" and "delta connected" are capable of being supplied with 415V, each equally "no good" for used on a 240V VSD.
In your case......yes, thats what I'm saying.**
If you had a 415V VSD, as you would have full power, you could likely get the speed range you are after with only the one motor speed.
In your case a 415V VSD isnt an option as you cant supply the power to run it. Which is why I suggested running the motor on 240V "as wired" as this limits the power required.
With a 240V VSD you're going to be down 50% on hp to start with, so will have a smaller usable range of speed adjustment with the VSD(mostly downwards according to Bob tests)
As always.... not sure I have made things any clearer :p
Stuart
*Now in theory I believe that you could change series delta to parallel delta then get full power(only on that speed, I cant see you can do anything about the parallel star) which is one of the things I set out to test. Of course this is no good to you as you can't supply full power.
**I've not fully tested a 415V two speed motor on a 240V VSD, and few tests I did seem a little "suss".