Around here (Detroit), industrial customers often have medium voltage services. In the newer areas, the utility distribution is 13.2. My understanding is that this is a wye service. From what I observe on the pole, the utility is giving customers 3 phase wires with a concentric neutral. This makes sense to me as far as grounding/ bonding go. Essentially, this is no different than a 480/277 utility service. The concentric neutral would be the fault clearing path back to the center of the utilities wye. The customer owned medium voltage gear would be bonded to the grounded conductor like a CT cabinet in a 480/277 service. Am I thinking correct so far?
In the legacy areas, customers get 4800 volt services. I understand this to be a Delta configuration. I don't understand how the grounded conductor works on these systems. Is a system like this typically corner grounded? Ungrounded? Where would the main bonding jumper be installed? I don't get it.
In the legacy areas, customers get 4800 volt services. I understand this to be a Delta configuration. I don't understand how the grounded conductor works on these systems. Is a system like this typically corner grounded? Ungrounded? Where would the main bonding jumper be installed? I don't get it.
