Practically Speaking: When Are Barriers Required for Feeder Terminations?
Section 215.15 was a new requirement for the 2023 Code — meant to increase safety in certain power distribution equipment where feeder conductors terminate. The requirement is one long sentence, so I’ll try to break it down piece by piece. It requires barriers to be installed to minimize the risk of accidental contact with energized, uninsulated, ungrounded terminals or busbars. This rule only applies to panelboards, switchboards, switchgear, and motor control centers. It does not apply to any other equipment where feeder wires are terminated. However, it does not apply to all feeders either. It only applies to equipment fed by transformer secondary conductors or feeder tap conductors.
Unfortunately, the requirement does not seem to apply to transformer secondary conductors and tap conductors equally. Let’s start with tap conductors first. If the panelboard in the photo is being fed from feeder tap conductors, the requirement for barrier installation applies to the line side terminals of the 100A main breaker when this breaker is in the “off” or “opened” position. Barriers would not be required on any load side busbars or load terminals of the other circuit breakers in the panelboard because they would not be energized if the main breaker was off. Ironically, barriers are apparently not required when the 100A main breaker is “on.” That’s a little weird!
I think that needs some clarification. If this panelboard was fed from transformer secondary conductors, the requirement for barriers to be installed seems to apply whether the 100A main breaker is either “on” or “off” because there is no mention of the disconnecting device for transformer secondary conductors. That could be problematic. Does this mean the line side terminals of the 100A main breaker (along with the busbars and all the load terminals of all the other breakers in this panel) would need insulating barriers too? Apparently, yes! However, I don’t believe that is the intent of this new rule. Like many new rules, the wording may take a few Code revision cycles to iron out all the wrinkles.
What if this was a main lug panelboard protected by a 100A fusible disconnect ahead of it? Would any barriers be required in either the fusible disconnect or the main lug panelboard? Nope. And, in this case, it wouldn’t matter if the fusible disconnect was fed by feeder tap conductors or transformer secondary conductors. In either scenario, barriers would not be required. Hopefully, the 2026 Code will provide some clarity on these requirements.
