Thread: Tripping circuit breakers

Hi there,
Quite a few weeks ago my bandsaw started blowing circuit breakers, not only on the shed sub-board, but also the main one in the house. Sometimes this happened during use, but eventually as soon as I tried turning it on.
I haven't got much time to look into things seriously in the shed so I just ignored it, thinking that sooner or later I'll have to get the motor checked out or replaced...like next year. But today I really needed to use it, ripping some 100x90 treated hardwood for the extension house deck. Really hard stuff, and I just couldn't will my arm to swing on the handsaw any more! So I wasted some valuable time doing maintenance instead of production...spent an hour and a half pulling the bandsaw apart.
I thought maybe it'll be some moving part putting excess friction on the drive, but no, everything was OK. So I unscrewed every cover or plate associated with the electrics: capacitor, junction box, on-off switch/relays, motor shroud. And every one of them was completely stuffed with sawdust!! 20yrs of accumulated dust was blasted out with the compressor...and Hey Presto! the beast worked again. Changed the blade, replaced a guide bearing, lubed the tension slides and tuned the thing up, and its a different machine. Made easy and accurate work of the ripping I had to do, not a hint that it would trip the breaker.
Although not really surprised at the cause of this problem, I'm just curious about the physics. I thought wood in itself is an insulator, so why would it allow a short circuit to flow? Maybe its a function of the humidity, as in the saw dust absorbing moisture and becoming conductive?

Cheers,