"NSM" writes:

"Sam Goldwasser" wrote in message
...

| | I have a bench grinder that seems to have such a fault. I have
eliminated
| | mechanical causes as best I can and it still intermittently stops and
| | hums loudly when the rotor gets hot.
|
| Bearings?
|
| That's what I thought originally but I couldn't find any problems.

If it's a cap run motor maybe the cap is shorting, otherwise a shorted turn
in the motor I think.

Could be though the effect seems to depend on the position (angle) of the
rotor. It's a split phase motor.

Also should note that if the rotor gets up to speed before it heats up,
the motor runs fine. Once it gets into funky mode, though, it can't
be spun up by hand unless it's done with power off.

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