Capacitors on induction motor tools

[mike]

I've had two tools die on me in the last fortnight. The first was a cement mixer and the second a table saw. Both had induction motors and in both cases it was the capacitor that supplies the starting torque that failed... an acrid smell followed by a humming and a failure to rotate, cured by a shove to the blade or barrel.

Both tools were under guarantee and the manufacturers were happy to put spare capacitors in the post but since I generally take care of tools and don't recall overloading either of them, I was wondering what put the kibosh on the capacitors in the first place?

The mixer manufacturer said that the capacitor should cope with a full load from a standing start even though they recommend starting the drum empty.

Is capacitor failure a general problem with induction motors?

Mike

[Ian Stirling]

Were you at the time starting them frequently? The capacitor is not rated for the continuous starting current, just intermittent.

They can also dry out over time.

[G&M]

No. Are you running them from mains or a generator. If the latter suspect this isn't performing to spec.

[geoff]

In message , mike writes

Yes

[mike]

Thanks for the reply.

Yes, they'd been started fairly frequently at the time. The table saw is a cheapie but I'd have expected the mixer to be made of sterner stuff.

[mike]

Thanks for the reply. They're both being run from the mains.