The smallest branch circuit conductors that can be installed between the circuit breaker and the motor for a 120/240-volt, 3Ø, 4-wire panelboard are how many AWG?

For a 120/240-volt, three-phase, four-wire system, the minimum size of branch circuit conductors is determined by the load that the circuit must support, but there are also specific requirements in the National Electrical Code (NEC) that guide conductor sizing.

In this context, for motor circuits, the NEC generally requires that the conductors be sized to handle the full-load current of the motor. For most typical applications in residential or light commercial settings, 14 AWG conductors are permitted for branch circuits that don't exceed a certain ampacity under specific conditions. This capacity aligns with typical circuit requirements for motors at lower loads.

Choosing 12 AWG, for instance, while it meets the requirements for higher current loads, is not the smallest permissible size for a circuit that is not expected to exceed 15 amps, making it an inappropriate choice in this case. Similarly, 10 AWG or 16 AWG conductors would either be too large for lightweight applications or too small for safety and efficiency, as 16 AWG is frequently not accepted for branch circuits feeding motors due to its limitations in current capacity.

Thus, the choice of 14 AWG represents the smallest size conductor that meets the NEC guidelines while providing adequate performance