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From the Q&A

With Russell Kincaid


soft motor start

Question:

I put this 5 hp motor on my table saw. It works like a miracle, but it jerks the arbor (saw blade) out of alignment. Is there a device or method to make this 230 volt, 3,450 rpm motor take more time — like maybe a whole second — to come up to speed?

— Chuck Larson


Answer:

The start winding on your motor draws a lot of current in order to give high torque to a heavy load, like an air compressor. Your application is essentially a no load start, so you don’t need that high of current. I suggest that you change the starting capacitor to a smaller value, perhaps 1/4 as much as is now being used.

PS: Feedback from Chuck — my guess of 1/4 was just right.


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