On Fri, 3 Feb 2017 19:34:45 +0000 (UTC), Massoud
wrote:

wrote in :

Hey All,
I have an old Baldor bench grinder. Probably 70 years old or older.
The motor is the type that uses a capacitor for starting and running.
There is no centrifugal starting switch. I know this type of phase
making scheme provides lower torque for starting so that the motor
takes longer to come up to speed. But this grinder takes 5 seconds to
reach operating speed, 3400 rpm. I replaced the bearings in the motor
and it now spins very easily. There is a 3/4 wide 6 inch grinding
wheel on one side and a light weight 6 inch diamond wheel on the other
side. The cap in the thing might be the original cap. It is a large
round tinned metal can with solder lugs. 330 volts and 400mfd. Could
it be that it needs a new cap? I don't know what kind of cap it is.
Oil filled I imagine but from the high mfd campared to all my other
run caps could it be an electrolytic cap? There is no sign of leaking
and there are two places on the top of the cap where it looks like
holes were sealed with solder.
Thanks,
Eric

You have a good start up, so no need to replace the cap.

5 seconds seems like too long. My other two Baldor grinders spin up to
full speed in 2 seconds. These grinders don't have a centrifugal
starting switch either so I assume they are wired just like my older
grinder. I'm concerned the long starting time might lead to
overheating the windings after many starts.
Eric