re: Danger of sawdust combustion?

As Jeff said, BARE wire is a proper ground wire. Even inside the hose it must be bare copper wire. No jacket no plastic, and grounded to the actual ground wire. Then the devise itself, the bare wire must be attacked to the metal on the frame. Most don’t have that luxury tho as they have machines on wheels cause space is at a premium and tools are on wheels. However any stationary tool can and should be grounded besides the ground on the cord. That’s what I do. My dust collection is only a shop vac, for now. But I have plans for a plenum fan, and, a hose system. They will have overkill grounding too. But then again my carrier as a fire trainer and qualifications as an electrical engineer have made me zealous as a proponent of fire safety.