Grounding in More than One Location?

[slushin]

So here's the situation: I have 5 generators paralleled to a paralleling switchgear. The generators are installed outdoors and the switchgear is indoors. The installer grounded the neutral of each generator and also grounded the neutral of the paralleling gear. When I discussed this with the installer, I told him that he needs to break the ground connection at either the generators or paralleling gear so that both are not grounded at the same time. His reply was that the generators, being outdoors are similar to a transformer being installed outdoors which, per NEC 250.24(A)(2) would require grounding at both the source and service panel. Does anyone have an opinion or code reference for this argument either way?

 

[dpc]

240.24 is for services. Your generators are a separately derived service. See 240.30. Grounding at both the generators and the switchgear can cause problems for ground fault relaying. Your grounding method needs to consider the impact on your ground fault sensors and relaying.