I am designing a dust collection system and I need to ground/bond the metal ductwork that can carry a potential charge. I have read the pertinent sections of the NEC, NESC, and NFPA 70B, but I am not completely sure what size conductor to use for the bonding between the two flanges. The NESC states that for bonding between electrodes, a copper wire of no less than 6 AWG shall be used. Should I also use this standard for metal ductwork? What is the best way to actually attach the grounding/bonding conductor to the metal ductwork? The duct would be galvanized steel. Any help would be greatly appreciated. Thank you!
References - NFPA 70 (Article 250), NFPA 70E, NFPA 70B, NESC (Section 9, 2006), and NFPA 664 22.214.171.124.1.8 (2017)