Matt Donovan
Member
- Location
- United States
I have an equipment rack on a rooftop which holds an 800A panelboard and a few pieces of equipment fed from that panelboard. The rack is made of unistrut, and is bolted to the roof with OMG anchors, but not bolted to the building steel (so, not electrically connected to the building structure). Do I need a bonding jumper from the panelboard to the equipment rack? If so, what size does that jumper need to be?
What everyone tells me is that I need the jumper if the rack is "likely to become energized". I can't imagine it becoming energized, since there's no exposed wiring on it - wiring is all in conduit. How do most AHJs interpret this?
In terms of sizing, it seems "obvious" to size the jumper for the size of the feeder equipment ground. I have a #3/0 feeder EGC. Do I really need a #3/0 bonding jumper landing on the unistrut rack? Usually I see #6 for this stuff, but don't know what the justification is for that sizing.
What everyone tells me is that I need the jumper if the rack is "likely to become energized". I can't imagine it becoming energized, since there's no exposed wiring on it - wiring is all in conduit. How do most AHJs interpret this?
In terms of sizing, it seems "obvious" to size the jumper for the size of the feeder equipment ground. I have a #3/0 feeder EGC. Do I really need a #3/0 bonding jumper landing on the unistrut rack? Usually I see #6 for this stuff, but don't know what the justification is for that sizing.
