Bonding - Seperate Structure

[sii]

I have a small wooden garage at our plant that formerly housed an air compressor. The compressor was fed by a non-fused disconnect which was in turn fed from a 3-pole breaker in panel in a separate building.

I wish to remove the disconnect, install a small 480V, 3-phase, 4-wire panel in this garage and move a couple hydraulic pumps inside. There is no water service to the garage, only sprinkler piping and compressed air, both of which will remain. Am I required to bond the sprinkler and compressed air piping to ground at the garage panel?

 

[kwired]

I have a small wooden garage at our plant that formerly housed an air compressor. The compressor was fed by a non-fused disconnect which was in turn fed from a 3-pole breaker in panel in a separate building.

I wish to remove the disconnect, install a small 480V, 3-phase, 4-wire panel in this garage and move a couple hydraulic pumps inside. There is no water service to the garage, only sprinkler piping and compressed air, both of which will remain. Am I required to bond the sprinkler and compressed air piping to ground at the garage panel?

Unless they also are a qualifying grounding electrode, I'd say they need to only be bonded to the EGC of the branch circuit that is likely to energize them, and if not likely to become energized they may not need bonded at all.

 

[infinity]

I have a small wooden garage at our plant that formerly housed an air compressor. The compressor was fed by a non-fused disconnect which was in turn fed from a 3-pole breaker in panel in a separate building.

I wish to remove the disconnect, install a small 480V, 3-phase, 4-wire panel in this garage and move a couple hydraulic pumps inside. There is no water service to the garage, only sprinkler piping and compressed air, both of which will remain. Am I required to bond the sprinkler and compressed air piping to ground at the garage panel?

You'll need to add a GES. Could be as simple as two ground rods and a piece of #6 copper.

 

[sii]

Unless they also are a qualifying grounding electrode, I'd say they need to only be bonded to the EGC of the branch circuit that is likely to energize them, and if not likely to become energized they may not need bonded at all.

Neither are likely to become energized. Knew I needed rods, just wasn't sure if I needed to bond the other piping.

 

[kwired]

Neither are likely to become energized. Knew I needed rods, just wasn't sure if I needed to bond the other piping.

250.104 is what addresses this. The air line definitely falls under "other metal piping" but the sprinkler may or may not be considered water piping. I think most would call it other metal piping though.

A metal water pipe has to be bonded according to 250.104(A).

Edit: A metal water piping system has to be bonded, can open a new can of worms when determining if the system is metal or not if there is some nonmetallic piping involved.