Service rated switchboard

[hhsting]

Attached sketch shows service rated switchboard fed from local electric utility conductors.

The switch has two main service disconnects in compartment #1 and compartment #2.

I have plans that show each compartment #1 and #2 has neutral to ground bond i.e main bonding jumper.

It is one ul listed assembly switchboard. I find this odd because usually they comply with 250.24(B) exception 1 you have one main bonding jumper for the whole assembly.

Has anyone seem something like below? Can below be done and be compliant with code?

 

[electrofelon]

I would trust what the manufacturer did and move on.

 

[don_resqcapt19]

There is no prohibition on multiple points of connection between the neutral and ground on the line side of the service disconnect or within the equipment that contains the service disconnect.

 

[hhsting]

There is no prohibition on multiple points of connection between the neutral and ground on the line side of the service disconnect or within the equipment that contains the service disconnect.

The plans also show two grounding electrode conductors. One from compartment #1 and second from compartment #2. Now those grounding electrodes are by the engineer. Can you have two or one would be enough?

 

[don_resqcapt19]

The plans also show two grounding electrode conductors. One from compartment #1 and second from compartment #2. Now those grounding electrodes are by the engineer. Can you have two or one would be enough?

That is a design choice and not a violation and there is no need for you to look at it.

 

[hhsting]

That is a design choice and not a violation and there is no need for you to look at it.

I think designer maybe getting confused with 250.64(D)(1) because those two grounding electrode conductors one from compartment #1 and another from compartment #2 go to ground bus which then bond all grounding electrode at the bus. He even has each disconnect with main bonding jumpers from each compartment as if they are from two separate enclosures supplied by one service and mentioned in 250.64(D)(1).

This is all in one list assembly switchboard with separate vertical section its MLO with two main breakers. Sure they are in two separate vertical enclosures but i dont see how 250.64(D)(1) apply here. Would 250.64(D)(1) even apply to this?

 

[don_resqcapt19]

I think designer maybe getting confused with 250.64(D)(1) because those two grounding electrode conductors one from compartment #1 and another from compartment #2 go to ground bus which then bond all grounding electrode at the bus. He even has each disconnect with main bonding jumpers from each compartment as if they are from two separate enclosures supplied by one service and mentioned in 250.64(D)(1).

This is all in one list assembly switchboard with separate vertical section its MLO with two main breakers. Sure they are in two separate vertical enclosures but i dont see how 250.64(D)(1) apply here. Would 250.64(D)(1) even apply to this?

There is no code violation, the design is code compliant. There is no restriction on how many GECs are brought to the equipment. It is a design issue and not a code issue...nothing for you to look at.

 

[LadyDi]

Think of the entire metal enclosure (compartments 1 & 2 including screws) as an equipment grounding conductor to the main bonding jumper and grounding electrode system.

At a main service, is the referenced design different than installing a grounding electrode conductor to a metal water pipe and another conductor from the service to a concrete encased electrode?