Do you have to bond the disconnect and the cabinet grounding?

[Cjmccarthy]

The power and cabinet is located outside on the side of the highway, we bring 600v and go through a disconnect and stepdown transformer. At the disconnect, it is bounded to a ground rod >5 ohms. At this particular site we have no lightning protection, just a ground array for the cabinet >5 ohms. My question is, does the disconnect have to be bounded to the cabinet ground array? The cabinet is within 5 feet of the disconnect.

 

[Barney B]

1. Item 12 on your drawing qualifies as a service disconnect and thus the enclosure for this switch, unless it is non-conductive, must be bonded to your grounding electrode system.
2. Terminal X₀ on your transformer must also be bonded to your grounding electrode system, but that connection is permitted to be either in the transformer enclosure or in the enclosure containing your service overcurrent protection device(s).

 

[Cjmccarthy]

1. Item 12 on your drawing qualifies as a service disconnect and thus the enclosure for this switch, unless it is non-conductive, must be bonded to your grounding electrode system.
2. Terminal X₀ on your transformer must also be bonded to your grounding electrode system, but that connection is permitted to be either in the transformer enclosure or in the enclosure containing your service overcurrent protection device(s).

Thank you, that I understand. I read somewhere in the NEC that the disconnect has to be bounded to the lightning protection, we do not have lighting protection at this site, but the cabinet and devices has a separate ground system, I didn't know if that needs to be bounded to the disconnect ground making it a single ground.

 

[Cjmccarthy]

Thank you, that I understand. I read somewhere in the NEC that the disconnect has to be bounded to the lightning protection, we do not have lighting protection at this site, but the cabinet and devices has a separate ground system, I didn't know if that needs to be bounded to the disconnect ground making it a single ground.

Maybe I am using the wrong terminology when I say "Bonded", should the ground rod for the disconnect be tied in with the ground rod of the cabinet?

 

[Barney B]

Yes. All grounding electrodes on a premises must be bonded together.