"Dan Lenski" writes:

Charles Schuler wrote:
Was that graphite grease? How much did you get on the motor/electrical
contacts? Seems a bit strange!

It was white lithium grease. Not conductive. I use it on bearings in
bicycles and lab equipment all the time, so I figured it would work
fine on the garage door pivots and the bearings in the motor.

When I sprayed it inside the motor housing, I tried to carefully aim it
only at the mechanical bearings, and NOT at the electrical contacts.

I agree that it's very strange, but the coincidence seems very
unlikely. Although the capacitor was evidently nearing the end of its
service life in any case (16k cycles).

I'm not convinced that it's a coincidence. If you really sprayed grease
inside the motor, you may have gotten it on the contacts of the centrifugal
switch that is supposed to interrupt the circuit to the start cap once the
motor gets up to speed. If the start cap remains energized for more than
the time needed to start, it will do exactly what you describe quite quickly.

So, at the very least, you should check the AC voltage on the start cap
using a meter that reads only AC (not the DC omponent). It should go to
0 VAC once the motor is turning at normal speed. If not, you'll have to
disassemble the motor and determine what's going on. And have your safety
goggles on while doing it!

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