Question

What's the smallest size copper equipment (bonding jumper) for a system that supplies Class 1-3 circuits and is derived from a transformer?

Answer 1

The smallest size bonding jumper for a system supplying Class 1-3 circuits derived from a transformer is determined by the National Electrical Code (NEC). According to NEC Table 250.66, the minimum size for copper conductors is 6 AWG for Class 1 circuits and 8 AWG for Class 2 and 3 circuits.

Step-by-step explanation:

The smallest size copper equipment, or bonding jumper, for a system supplying Class 1-3 circuits and derived from a transformer is determined by the National Electrical Code (NEC). According to NEC Table 250.66, the minimum size of the bonding jumper should be based on the size of the circuit conductors. For copper conductors, a minimum size of 6 AWG is typically required for Class 1 circuits, while a minimum size of 8 AWG is required for Class 2 and 3 circuits.