Next Generation Motors

Although a motor can usually rotate in both directions, a centrifugal pump cannot. Therefore it is far more efficient as far as the pump's duty as a process fluid mover to make the motor for a centrifugal pump spin in the correct direction only.

i read this single direction motor thread in this forum last year it is efficient than conventional motors but i could not get that link

I JUST have to add this:

When working a company that used hundreds of centrifugal pumps, mostly 3 phase, we'd occasionally get a pump that would only produce about 50% of rated performance.

It had usually been wired by a rookie, who didn't bother to check motor rotation and was running backwards.

How to Search the Internet - Hannon Library

So where did you find this "How to search the internet" thingy?

Its application very much intrigues me!

I wouldn't bother. I don't think it'll ever catch on. At least not here.

I know of no motors that can inherently only rotate in one direction.

A number of OEMs are now using what are called SPM (Surface-mounted Permanent Magnet) or IPM (Internal Permanent Magnet) AC induction motors because they are more efficient than Squirrel Cage Induction Motors. Although not absolutely necessary, these new PM motors are often combined with VFDs because they are maximizing efficiency in every way possible. In a few cases, the motor suppliers are building the VFDs into the motor end bell itself. If this is for an OEM pump application, I can see the OEM disabling the ability to have the VFD run in the wrong direction, because as was said, pumps don't work running backward.

So all I can think of is that you may be seeing a PURPOSEFUL disabling of that capability, but it is not inherent. If you want to use an SPM or IPM motor that needs to run in reverse, just buy a standard one, not one custom made for a pump OEM.

Sometime back I can remember reading that researchers have found that making motor lamination & slot in a certain pattern will produce more efficient motor but in one direction only. As all the machines do not reverse it is sufficient for common use.

tanq Mr panaban, if u remember in this forum same topic was there one year before i could not get that thread .....i an still searching

Sorry I cannot remember,but if I come across it ,I will.