In Scenario 230.26, the smallest branch circuit conductors that can be installed between the 1-pole circuit breaker and the motor are which AWG?

In Scenario 230.26, the smallest branch circuit conductors that can be installed between the 1-pole circuit breaker and the motor are which AWG?

• A. 12
• B. 10
• C. 8
• D. 6

Answer: (C)

Sizing motor branch-circuit conductors centers on making sure the wiring can carry both the running current and the startup surge without overheating, while matching the protection device that guards the circuit. For a motor fed from a single-pole breaker, the conductors must have an ampacity not less than the motor’s full-load current (with an allowance for startup, typically approximated by using a higher ampacity requirement). When you work through that allowance and choose the next standard conductor size that meets it, 8 AWG copper emerges as the smallest size that will safely carry the motor current in this scenario. Smaller conductors would be undersized for the motor’s running and startup demands, while larger sizes would still work but aren’t the minimum required. Hence, 8 AWG is the correct minimum.

Sizing motor branch-circuit conductors centers on making sure the wiring can carry both the running current and the startup surge without overheating, while matching the protection device that guards the circuit. For a motor fed from a single-pole breaker, the conductors must have an ampacity not less than the motor’s full-load current (with an allowance for startup, typically approximated by using a higher ampacity requirement). When you work through that allowance and choose the next standard conductor size that meets it, 8 AWG copper emerges as the smallest size that will safely carry the motor current in this scenario.

Smaller conductors would be undersized for the motor’s running and startup demands, while larger sizes would still work but aren’t the minimum required. Hence, 8 AWG is the correct minimum.