Duct work non-metallic separation

[Gategator37]

I know that through the furnace equipment grounding conductor that it attaches to the ductwork so therefore is "bonded", but what if there is a non-metallic separation? Does this need to be "jumpered" or only if it is likely to become energized?

 

[jumper]

I know that through the furnace equipment grounding conductor that it attaches to the ductwork so therefore is "bonded", but what if there is a non-metallic separation? Does this need to be "jumpered" or only if it is likely to become energized?

I bond around rubber HVAC collars.

Is it code? IDK. I just do it.

 

[Dennis Alwon]

I have never done any extra bonding for the duct work however I often wondered about it. I don't know where in the NEC it requires duct work to be bonded. I see metal piping, structural metal, water pipes, but nothing on duct bonding.