With the 2014 NEC, the rules for feeder identification [215.12] are greatly expanded. That’s because the 2014 NEC adds rules for ungrounded feeder conductors supplied by DC systems [215.12(C)(2)]. These rules will probably change with the 2017 NEC, because they are new and because solar continues to grow.
Regardless of source, two rules haven’t changed:
- Identify the grounded conductor per Sec. 200.6. Remember, this is the grounded, not grounding, conductor. Typically, it’s the neutral.
- Identify the grounding conductor per Sec. 250.119.
Each of these (200.6 and 250.119) is about a full page of requirements depending on conductor size and/or type. For example, there are eight methods permitted for identifying the grounded conductor if it’s 6 AWG or smaller, but only four if it’s 4 AWG or larger.
For ungrounded feeder conductors supplied by AC systems, the rules have barely changed. If the ungrounded conductors are supplied from the same nominal voltage system, you don’t have to identify them.
Otherwise, you must identify each ungrounded conductor at each termination, connection, and splice point. You can do this by any approved means, including color coding or tagging. But you must document the method in a manner that is readily available, or permanently post documentation of the method (e.g., a sign or legend) at each feeder panelboard or similar feeder distribution equipment.
