Code Quiz: Article 430, Part 5
Based on the 2020 NEC
Questions and answers written by
Mark Lamendola, who has worked as a master electrician, electrical
inspector, and design engineer. Mark is an IEEE Senior Member, and the
Code article author for Codebookcity.com. Since 1996, he has been writing National Electrical Code articles for electrical trade magazines and has an extensive portfolio of hundreds of NEC articles.
Article 430 provides the requirements for motors, including the hermetic motors that also have additional requirements covered in Article 440. Many other articles also may apply to a given motor installation. Article 430 is the largest article in the NEC.
Part V specifies protective devices intended to protect motor feeder conductors from what? And what do they not protect against, that OCPDs for non-motor feeders and branch circuits protect against?
- A feeder supplying a specific motor load and consisting of conductor sizes based on 430.24 must have a OCPD with a rating or setting that is X of/than the largest rating or setting of the branch circuit OCPD. What is X?
b. Greater than.
c. Less than.
- If the feeder conductors have an ampacity greater than that required by 430.24, can you base the feeder OCPD on the ampacity of the feeder conductors regardless of the size of the branch circuit OCPD?
- Those three quantities are:
1. For a single motor, the rating permitted by 430.52.
2. For a single hermetic refrigerant compressor motor, the rating permitted by 440.22.
3. For two or more motors, the rating permitted by 430.62.
- Yes, there is an exception. Use the provisions of 430.94 when the feeder OCPD provides the overcurrent protection for a motor control center.