Main Bonding Jumper

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SMB

SMB

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Is it legal to install a green screw (manufacturer provided) through the neutral bus into the back plate of a service entrance disconnect and not route a physical conductor between the neutral bus and ground bus to make the N-G bond? The ground bus is also connected to the back plate with a screw. Looks like 250.28(B) allows this.

Thanks for any and all responses.
 
Very common installation practice. That is the reason that the green screw is included with the disconnect.

Chris
 
Government facilities I have dealt with have required a physical conductor between the two to ensure the bond exists by simply inspecting. Some dont trust the "screw" method....even though it is spelled out in the code.

Thanks for your replies.
 
I agree with everyone however I want to make sure of one thing. Are you adding an equipment grounding bar and connecting neutrals to it? In that case the screw is not enough to meet code--I would have to hunt that article down but that may be what the facility people are talking about.
 
Dennis Alwon said:
I agree with everyone however I want to make sure of one thing. Are you adding an equipment grounding bar and connecting neutrals to it? In that case the screw is not enough to meet code--I would have to hunt that article down but that may be what the facility people are talking about.
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Dennis are you referring to 200.2(B)?

Chris
 
For clarity, the the screw connects the neutral bus to the back of the box. The ground bus is separate of the neutral bus and is also connected to the box by a screw and connects a driven ground rod. This does not seem to violate 200.2(B) as the grounded conductors on both the supply and load side connect to this neutral bus.
 
SMB said:
Government facilities I have dealt with have required a physical conductor between the two to ensure the bond exists by simply inspecting. Some dont trust the "screw" method....even though it is spelled out in the code.
Click to expand...
It sounds like they don't trust the enclosure metal being part of the bonding pathway.
 
SMB said:
For clarity, the the screw connects the neutral bus to the back of the box. The ground bus is separate of the neutral bus and is also connected to the box by a screw and connects a driven ground rod. This does not seem to violate 200.2(B) as the grounded conductors on both the supply and load side connect to this neutral bus.
Click to expand...

Correct, 200.2(B) would only apply if you were connecting neutral conductors to an equipment grounding bus at the service equipment that relied on the enclosure for continuity of the neutral conductor.

Chris
 
SMB said:
For clarity, the the screw connects the neutral bus to the back of the box. The ground bus is separate of the neutral bus and is also connected to the box by a screw and connects a driven ground rod. This does not seem to violate 200.2(B) as the grounded conductors on both the supply and load side connect to this neutral bus.
Click to expand...
If the driven ground rod is the service grounding electrode, it is not permitted to connect the the ground bus. It must directly connect to the neutral bus where the main bonding jumper is a screw.
 
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