Relocation of residential grounding electrode conductors

[thisisausername]

I will be inserting a transfer switch between my home's meter base and load center. The transfer switch will take over main breaker duty and function as the service disconnect, with the load center acting only as a sub panel. The load center and transfer switch will be in the same structure and room.

In this scenario, must I relocate the two grounding electrode conductors (200A service) from the load center (now a sub panel) to the transfer switch's (now the service disconnect's) ground bar? The load center will of course no longer have neutral bonded while the transfer switch will, and the load center's ground bar will be connected to the transfer switch's ground bar. Physically, it seems almost the same to me whether the GECs are relocated or not, with the only difference being that the service disconnect's (now transfer switch's) ground bar has one physical path to those two electrodes instead of two.

The transfer switch's installation manual does not mention this at all, but my instinct is that I would need to relocate the GECs. Section 250 is quite long and is taking some time for me to break down and decipher. All I've been able to find via Google is this PDF from a state in which I don't live, and its answer implies that whoever wrote it doesn't even understand that neutral shouldn't be bonded at the sub panel.

 

[infinity]

I've approved your thread but you'll need to update your actual occupation and change your location. It doesn't need to be any more granular then the state you're in.

 

[roger]

All I've been able to find via Google is this PDF from a state in which I don't live, and its answer implies that whoever wrote it doesn't even understand that neutral shouldn't be bonded at the sub panel.

I don't know how you read the PDF but it states

Therefore, section 250.24(A) requires the grounding electrode conductor be removed from the subpanel and connected to the neutral service conductor as described in 250.24(A)(1), which includes the neutral terminal bar in the transfer switch.

 

[thisisausername]

Maybe a picture will help.

I don't know how you read the PDF but it states

As for the linked document from NC (which I know doesn't reference NEC 2023, but it's the only opinion I could find), its opinion states:

...requires the grounding electrode conductor be connected to the grounded service conductor (neutral in most installations).

Which it would be in B).

...Once the transfer switch is installed as the new service disconnect making the existing main panel a subpanel, the existing grounding electrode conductor connected to the neutral in the former main panel is no longer connected to the neutral service conductor at the service disconnecting means.

In B), GEC would not be connected to neutral in the subpanel as their opinion states. Or does this not fly because that intermediary ground bar counts as a splice for the GEC?

 

[roger]

Can you tell us what you're retired from?

 

[roger]

The forum rules do not allow us to assist with DIY projects, you can try diychatroom.com