i couldn't see anything there and seeing as I only cut polystyrene with it I would expect that any chippings would do it. I was also only cutting air when it happened.

any way the earth lead could short it out as that the only thing I noticed was a little dodgy.

the only other thing I was doing at the time was flushing the spindle coolant with warm water to flush out all the gunk from being sat for 6mth. ( not next time drain it before I go away)