What is the largest 1-pole breaker allowed for a 12 AWG copper Type SJO flexible cord?

What is the largest 1-pole breaker allowed for a 12 AWG copper Type SJO flexible cord?

• A. 25
• B. 20
• C. 15
• D. 30

Answer: (A)

Ampacity and overcurrent protection for flexible cords depend on the insulation’s temperature rating. For a 12 AWG copper conductor in a Type SJO flexible cord, the insulation is rated at 90°C, which gives an ampacity of 25 A under NEC guidelines. That means the overcurrent protective device (the breaker) can’t exceed 25 A for a single-pole protection. A 25 A breaker is the largest that can be used with this cord; a 20 A breaker would be permitted but not the maximum, and a 30 A breaker would exceed the cord’s capacity.

Ampacity and overcurrent protection for flexible cords depend on the insulation’s temperature rating. For a 12 AWG copper conductor in a Type SJO flexible cord, the insulation is rated at 90°C, which gives an ampacity of 25 A under NEC guidelines. That means the overcurrent protective device (the breaker) can’t exceed 25 A for a single-pole protection. A 25 A breaker is the largest that can be used with this cord; a 20 A breaker would be permitted but not the maximum, and a 30 A breaker would exceed the cord’s capacity.