On Wed, 18 Jul 2018 19:36:47 -0700, Jeff Liebermann
wrote:

On Wed, 18 Jul 2018 13:18:42 -0700, wrote:

Any reason for not disclosing the motor model number? Yes, I know
it's 40 years old and Granger can't find it.

There are two caps in most such motors. One is the "starting
capacitor". The other is the "run capacitor".
https://www.youtube.com/watch?v=qsuzfz5qcIE
https://www.youtube.com/watch?v=OMd9QkinXz4
I'm fairly sure they should NOT be wired in parallel.

For 220VAC, the starting cap should be about 30 to 50uF/kW.
3HP(mechanical) = 2.2kW so try about 90uF.

The run cap is usually about 5 - 20uF.

For the starting capacitor calculations, see:
https://www.electricneutron.com/electric-motor/single-phase-capacitor-sizing/
https://www.quora.com/How-do-I-calculate-capacitor-value-for-single-phase-motor
Mo
https://www.google.com/search?q=calculate+motor+starting+capacitor

I couldn't find anything on calculating the run capacitor.
Looking again I see that there are TWO model numbers on the motor
nameplate. The top one is 5K483-D, which is a good number as I found
it on the Grianger website. The other model number is on the bottom of
the ID plate and it says Motor Model Number whereas the top model
number just says Model. I have never seen this before. Anyway, I
called Grainger because the cap(s) weren't listed. The guy at Grainger
had to pull a file but he did find the caps and there are two. Both
caps are 485-582 MFD and are wired in parallel. They are both start
caps and the motor has no run cap. I have two cap coming tomorrow but
they are 540-685 MFD. Will them maybe be a problem? In the meantime I
will try to get the proper caps.
Thanks,
Eric