For a motor with a supply from a 120/240-V 3-ph panel, the minimum size circuit conductors are ___ AWG.

For a motor with a supply from a 120/240-V 3-ph panel, the minimum size circuit conductors are ___ AWG.

• A. 10
• B. 6
• C. 8
• D. 14

Answer: (A)

In determining the minimum size circuit conductors for a motor supplied from a 120/240-V three-phase panel, the National Electrical Code (NEC) provides guidelines to ensure safety and efficiency in electrical installations. The correct answer of 10 AWG is derived from the NEC requirements for motor circuits, which take into consideration factors such as load current, motor horsepower, and permissible voltage drop. For a three-phase motor operating at 240 volts, the NEC recommends using conductors sized according to the full load current of the motor. Generally, for small to medium-sized motors, the full load current can be calculated based on the horsepower rating. After calculating the full load current, the appropriate conductor size can then be selected based on NEC tables, which specify minimum conductor sizes depending on the amperage demand. When sized correctly, 10 AWG conductors are suitable for many motors where the full load current does not exceed the safe carrying capacity, ensuring that the circuit can handle the electrical load without overheating or causing a voltage drop that could affect motor performance. This choice aligns with safe practices described in the NEC for minimizing potential risks associated with undersized conductors. In contrast, other gauge options such as 6 or 8 AWG may be unnecessarily large

In determining the minimum size circuit conductors for a motor supplied from a 120/240-V three-phase panel, the National Electrical Code (NEC) provides guidelines to ensure safety and efficiency in electrical installations. The correct answer of 10 AWG is derived from the NEC requirements for motor circuits, which take into consideration factors such as load current, motor horsepower, and permissible voltage drop.

For a three-phase motor operating at 240 volts, the NEC recommends using conductors sized according to the full load current of the motor. Generally, for small to medium-sized motors, the full load current can be calculated based on the horsepower rating. After calculating the full load current, the appropriate conductor size can then be selected based on NEC tables, which specify minimum conductor sizes depending on the amperage demand.

When sized correctly, 10 AWG conductors are suitable for many motors where the full load current does not exceed the safe carrying capacity, ensuring that the circuit can handle the electrical load without overheating or causing a voltage drop that could affect motor performance. This choice aligns with safe practices described in the NEC for minimizing potential risks associated with undersized conductors.

In contrast, other gauge options such as 6 or 8 AWG may be unnecessarily large