Guys,
Have a question as to when ground detectors are required based on 250.21(B) in the 2008 NEC. In a situation where there is a 277/480V 3-phase, 4-wire (three phases and neutral) main panel with 3-phase, 3-wire (no neutral) branch circuits from it to a transformer or sub-panel, are ground detectors required on the branch circuits? Assuming that the main panel is grounded (bonded to water pipe, building steel, etc.), I would consider this to be a grounded system, but I'm not sure if the code is telling me that despite this, ground detectors are required on the branch circuits due to the lack of a neutral with them.
Thanks,
Creig
Have a question as to when ground detectors are required based on 250.21(B) in the 2008 NEC. In a situation where there is a 277/480V 3-phase, 4-wire (three phases and neutral) main panel with 3-phase, 3-wire (no neutral) branch circuits from it to a transformer or sub-panel, are ground detectors required on the branch circuits? Assuming that the main panel is grounded (bonded to water pipe, building steel, etc.), I would consider this to be a grounded system, but I'm not sure if the code is telling me that despite this, ground detectors are required on the branch circuits due to the lack of a neutral with them.
Thanks,
Creig
