Adrian Tuddenham <adr...@poppyrecords.invalid.invalid> wrote:
> Peter Jason <
p...@jostle.com> wrote:
>
> > 4-pole 3Ph squirrel -cage motor noisy.
> >
> > A loud buzzing noise has developed over the past
> > 12 months. The motor is not overheating, nor are
> > the bearings.
> >
> > Is this serious?
>
> If it has a phase-shift capacitor, that has probably changed value ...
My apologies, I didn't spot that you had said it was 3Ph.
It could be one phase disconnected, although that probably would make
more of a hum than a buzz. Laminations could be working loose in the
rotor or the windings working loose in the stator; the former will be
more likely to change on load or pulsate at slip frequency.