In a large industrial facility where you have transformers through-out the buildings, is each transformer considered separately derived? These would be a typical 45-100 KVA, with 480 primary and 110/208 secondary. The only place you bond the nuetral and ground would be at the main service. All panels after that, the nuetal bars and equipment grounds would be separate, right? An engineer wanted UPS panels treated like Main panels, and I was telling him that you have to treat them like sub panels. Just because a UPS feeds a panel, it's not the same as a separately derived system. It would be great if some one could clarify this. These transformers would all be in the same building. Thanks
