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Old 10-01-2016, 05:25 PM
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Silverback Silverback is offline
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Join Date: Jul 2004
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Ironman, I totally missed this post and just noticed it:

Quote:
Originally Posted by Ironman View Post
Rod, I'd agree with you at that rpm. I have never had a unit at less than 1000rpm
The quincy I have is 1200, the the triple one before it was 1400, and I have a huge Rand that is rated 98cfm output at 1100rpm.

But some of the larger single cylinder ones are down at 800 I am told.
Just looked up the Kellog and they said the pump needs 800 - 1000 rpm to generate the rated cfm, so I would run at 1000. just my way of thinking.

I found a manual here and the pump charts are worth a look. For this situation, 5hp limits the output to about half the max and between 700-800 rpm. I see a jackshaft in Mark's future.
I think this partially answers my question, you think 5hp will be limited to about 800rpm? Why? How did you do that math? Are you calculating off of the no load or some approximated loaded speed?

I was debating between 2 sets of pulleys and about to order but one would put me at 966rpm or 940rpm (no load, I was guessing in the mid/high 800's loaded) which now you have me wondering if that's ambitious for the motors I have available.

I REALLY don't want to run (or build) a jackshaft...
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