Common grounding electrode

[nrselect]

250.58 Common Grounding Electrode. Where an ac system
is connected to a grounding electrode in or at a building
or structure, the same electrode shall be used to ground
conductor enclosures and equipment in or on that building or
structure. Where separate services, feeders, or branch circuits
supply a building and are required to be connected to a
grounding electrode(s), the same grounding electrode(s) shall
be used.
Two or more grounding electrodes that are bonded together
shall be considered as a single grounding electrode
system in this sense.

Hello, I am installing a new meter base and service equipment in a multiple occupancy building. My question is if I need to run my ground all the way to where the grounding electrode of the building is or could I just drive down a ground rod near my new panel. Thanks.

 

[Dennis Alwon]

You need to be more specific. There is equipment grounding conductor and grounding electrode conductor . If you add a new meter then you will need to connect to either existing ground rods or add new ones if none exist.

The grounding electrode conductor gets connected either in the meter base, if power company allows, or in the first disconnect. The grounding electrode conductor to the water pipes or other electrodes also gets connected back to the main panel or meter.

 

[infinity]

The new service needs to connect to the existing building GES. 250.58 is typically used in high rise buildings as a way to bring a grounding riser up to allow multiple connections, usually for transformer GEC's.