- Washington Ga USA
- Licensed Electrical Contractor and Building Official for local City/ County
Forgive me for the length of this thread. I am looking into an issue at a broiler farm. 4 enclosures 75 wide by 750 long. Since they were commissioned they have all had trouble with burning up computer control boards, not in the same enclosure every time, and not the same board every time. Very random when it happens, but mostly after a thunderstorm. The service(s) are identical but fed from different pad mount transformers. From xformer 2 sets of 350 al conductors one each into a pair of 400 amp disconnects. I know this is light but that is the POCO wire so they put in what they want. From the disco there are parallel two 4/0 AL one 2/0 AL and one 6awg copper ground into each of 2 400 amp automatic transfer switches. Also out of each disco is a #2 copper going out to a ground rod. From each ATS is the same 4 wire configuration going into a 400 amp distribution panel. Out of this panel two feeders each from a 200 amp breaker go to one panel in each of 2 enclosures. Neutrals and grounds are separated in each of these panels and each panel has a #4 copper going outside to its own ground rod. This is one side, the second side mirrors it. All the equipment in the service is bonded together and to all six ground rods. The rods are 30 feet apart at a maximum an at minimum 6 feet apart. The ground rods at the enclosures are not bonded together except at the service equipment, same with the rods from the disconnects. I first thought it was a grounding/ bonding issue, but now I do not know. Any ideas would be appreciated.