Bonding vs Grounding
Bonding vs Grounding
(OP)
Disclosure, I'm an architect (yes I know, that says it all...
I noticed in the NEC that bonding jumpers are required between the *metal* boxes, raceways, etc to provide GF continuity. I've also noticed them on some jobs, but not all. I can't figure out if this secondary GF path is always required or just necessary when using a metal system... For example, not required if PVC conduit/boxes are used. Perhaps they are only req'd for certain Bldg Types?
One thought is that the bare copper wire found in most elec cable somehow preclude this jumper system since it seems integral w/ the entire grounding system (and does not seem to be coverd in the NEC. But that's only an "aesthetic" observation.
Can anyone clarify this for me please?
Thx
Dennis
I noticed in the NEC that bonding jumpers are required between the *metal* boxes, raceways, etc to provide GF continuity. I've also noticed them on some jobs, but not all. I can't figure out if this secondary GF path is always required or just necessary when using a metal system... For example, not required if PVC conduit/boxes are used. Perhaps they are only req'd for certain Bldg Types?
One thought is that the bare copper wire found in most elec cable somehow preclude this jumper system since it seems integral w/ the entire grounding system (and does not seem to be coverd in the NEC. But that's only an "aesthetic" observation.
Can anyone clarify this for me please?
Thx
Dennis





RE: Bonding vs Grounding
Besides, we intentionally make it complicated for job security.
Anything metal that might become energized has to be grounded for safety reasons.
RE: Bonding vs Grounding
But it seems like if there is/was a bare copper wire in addition to neutral in a 3or4 wire cable bundle, it'd be acting as the GF path to ground anyway. Are these bare grounding wires not used in some cases for some reasons?
/D
RE: Bonding vs Grounding
Steve Wagner
RE: Bonding vs Grounding
DCP/Steve
Thx, I reread NEC 250 and found it interestg that so much of the 2005 is devoted to this subj and so little clarifies use of non metallic raceways. But I see now why the bare wire is used or not used and of course the importance of the GF path when a potential fault might occur w/ metal. I haven't seen a lot of PVC/non-metal on commercial proj but was curious.
Thx again for the clarification.
/Dennis