Supplemental Grounding Conductor

[JJSS]

I have the following problem the electrical designer specified a ground ring #4/0 around a new expansion area of an existing industrial building. The drawings indicates that this ground ring should be connected to the existing ground ring. The problem is that it can not be found. The new ground ring is going to be use only for security to connect a supplemental ground. The circuit comming from the existing MCC an electrical equipment ground.

The question is can I have this ground ring with out a connection to the existing ground ring? Article 250-54 states that a grounding electrode shall be permitted, but it can not be used as a sole equipment grounding conductor.

 

[wbalsam1]

The existing ground ring should be tailed out to the service equipment...right? The grounding electrode conductor should be sized as per the largest grounding electrode conductor required throughout all the electrodes connected to it. See 250.64(F) code changes from 1999 to 2002 & 2002 to 2005.