What must be the basis for sizing the supply-side bonding jumper if the feeder is on the line side?

The appropriate basis for sizing the supply-side bonding jumper, particularly when the feeder is on the line side, is grounded in the requirements outlined in Section 250.102(C) of the National Electrical Code (NEC). This section provides explicit guidelines concerning the sizing of bonding jumpers based on the size and configuration of the service conductors or feeders. It emphasizes the importance of ensuring that these bonding jumpers are sufficiently sized to handle potential fault currents, thereby enhancing electrical safety and system reliability.

Choosing this option recognizes the authoritative nature of the NEC as a regulatory framework that governs electrical installations, promoting standardized practices for the bonding and grounding of electrical systems. Understanding these codes is crucial for ensuring compliance and safety in electrical work. Other options, such as local regulations or manufacturer guidelines, may influence practice but do not specifically address the sizing of supply-side bonding jumpers in the context provided by the NEC. Thus, referencing Section 250.102(C) provides a clear and enforceable standard.