Which NEC article governs motors for refrigeration compressors when using conventional (nonhermetic) motors?

• A. NEC Article 431
• B. NEC Article 438
• C. NEC Article 440
• D. NEC Article 430

Answer: (D)

This question tests knowing how the NEC organizes requirements for different kinds of motors and refrigeration equipment. When you have a conventional, nonhermetic motor driving a refrigeration compressor (the motor is separate from the compressor and not enclosed inside it), the rules you follow come from the part of the NEC that covers motors, motor circuits, and their controllers. That article sets how conductors are sized, how overcurrent protection is chosen, how the disconnect is located, and how starting and protection devices are arranged for motors.

The refrigeration equipment article, in contrast, is used when you’re dealing with equipment where the motor and compressor are integrated in a hermetic or semi-hermetic unit. Since the question specifies a conventional nonhermetic motor, you apply the motor-focused article, not the refrigeration equipment article.