Mike Dolt Enterprises
Mike Dolt Enterprises
User: Akten, Location: New York
Asked on: Tuesday, February 4, 2025 at 2:16 pm EST
Answered on: Thursday, March 6, 2025 at 8:14 am EST
Question: Hi,I am trying to interpret 240..21(C). Transformer secondary conductors can be installed without overcurrent protection at secondary, as specified in 240.21(C)(1) through(C)(6).My question is, do we just have to meet any one of the 6 conditions in 240.21(C) or do we have to meet all 6, in order to have transformer secondary conductor without secondary overcurrent protection?
You only need to meet one of the conditions in 240.21(C)(1) through (C)(6) to allow transformer secondary conductors to be installed without overcurrent protection at the secondary.The code explicitly lays out these conditions as alternatives. Each numbered paragraph presents a specific scenario where secondary overcurrent protection is permitted to be omitted if the stated conditions are met. They are not cumulative; you don't have to satisfy all of them.Think of it this way: The NEC presents a set of safe alternatives. If any of the specified alternatives are met, the secondary conductors are considered adequately protected.Therefore, carefully review each condition in 240.21(C)(1) through (C)(6) to determine which one, if any, applies to your specific installation. Flag for review