A breaker with two "hot" conductors under one screw is considered what?

A breaker with two "hot" conductors under one screw can be permissible in certain circumstances, which is why it is categorized as "not a defect if listed correctly." This means that if the breaker is designed and listed to accept two conductors simultaneously, it complies with electrical standards and requirements. This type of installation typically enhances the capacity of the circuit and allows for more efficient use of space in the breaker panel.

However, it is essential that the breaker label explicitly states that it is suitable for two conductors. The National Electrical Code (NEC) provides guidelines on this practice, ensuring safety and proper functioning. When two conductors are secured under one terminal, they should both be of the same gauge and type, ensuring that they do not create an overload condition or a potential safety hazard.

In contrast, if a breaker is not designed for multiple conductors and they are installed together, this could lead to issues such as overheating or circuit failure, which would render the installation as a defect or a violation of codes. Therefore, the correct answer emphasizes the importance of proper listing and installation practices in electrical work.