Although I stated that I would go into the 2014 NEC changes, I feel it would be more productive to address common problems found out in the field. This past week I had two different buildings that where undergoing services changes that had a common problem when I went to inspect. Both buildings had multiple services installed on them, but each service had a separate Grounding Electrodes. When I asked the contractors to fix it they had told they had never had to do this before. Each building had a 120/208 volt Y three phase service and a 277/480 volt Y three phase service installed next to each other both sporting two brand new Grounding Electrodes. I ask them to bond them together and was questioned as to what Code section they had violated. The following is the section from the NEC 2011.
Till next week, be safe.