"Written pole" single phase vs VFD and 3 phase motor

[ccjersey]

Anyone ever seen the inside of the large single phase "written pole" motors being sold by precise power for 30-75 hp loads?

http://www.precisepwr.com/Products.asp?bhcp=1

It's an interesting idea and I wonder how the expense of one of these patented motors and it's control would compare to an oversized VFD and an off-the-shelf VFD rated 3 phase motor? I know the usual single phase supply 3 phase VFD's are usually in the small <3hp range, but surely the same principles that allow this application in small VFD's apply to large ones as well?

 

[jraef]

What's the cost of your down time? A single supplier in the entire world poses a significant risk for anyone who is not within a 4 hour drive of their nearest warehouse. That makes it an issue for anyone not between Orlando and Naples, Florida.

If it's OK to be down for a few days, or you can afford to stock one spare of every size motor you have, it might be worth considering. I have yet to work at a place like that...

"If I had eight hours to chop down a tree, I'd spend six sharpening my axe." -- Abraham Lincoln
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[electricpete]

Anyone ever seen the inside

You can see a little bit of it on the video between 1 minute and 2 minutes

http://www.precisepwr.com/single_phase_motors.asp?bhcp=1

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(2B)+(2B)' ?