Sounds like you are NOT operating a commercial/industrial system judging from the use of PVC pipes. Unless you are operating with very fine dust particles at high velocities and high mass flow, I wouldn't worry about grounding. In other words, if your dust collector is less than 7.5hp (and probably much higher) , there is just not enough energy to cause any problems.
Most likely, some people will disagree, but if you do the calculations it will prove that point. BTW there was an article in one of the trade magazine a while back that did not find any hazard existed by NOT grounding small scale dust collection pipe systems.
PS My dust collection in my home shop is 6" SD platic pipe running on 7.5 hp and it is not grounded.
Cheers,
Bernhard |