My bench grinder let out the magic smoke

[RobCoxParticipant @robcox]

Saturday, as I was grinding some HSS toobits for a boring job I needed to do, my bench grinder got very hot on the case. Can't do without it, so I carried on. A short while later there was a small pop! followed by a puff of smoke.

I turned it off pronto, thinking how long was it going to take me to get a new grinder if the motor windings had cooked. I dismantled it from the stand and took the base off to look for problems and there it was..

The windings looked ok through the cable hole in the base of the case, so I guessed it was just the cap that had popped. I had a 2uF motor run cap handy, so I wired that in, and the grinder started up, albeit slowly, enabling me to finish the job.

The cap had let go so the value on the case had conveniently been erased by the goo that leaked out, so I emailed Warco, in hope rather than expectation, as to what value cap is fitted.

Hats off to them! Got a reply back on Tuesday. 10uF 450V. Have acquired one for RS, now fitted with a shiny new bracket rather than a bendy p-clip. The grinder starts as before the incident.

Rob

[RobCoxParticipant @robcox]

[Kiwi BlokeParticipant @kiwibloke62605]

It's often worth scouring dumps to look for discarded appliances which need only a replacement capacitor to be restored to health. The suppression caps across the mains, especially if paper dielectric, often let go too.

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