What is one requirement for electrical modifications as noted in Article 110.21?

The requirement that electrical modifications must not violate safety or performance requirements is crucial in maintaining the integrity and reliability of electrical systems. Article 110.21 emphasizes that any changes made to existing electrical installations should comply with the established safety standards and performance criteria set forth in the National Electrical Code. This ensures that the modifications do not compromise the safety of the electrical system, which could lead to hazardous situations such as electrical fires, equipment failure, or shocks.

Prioritizing safety and performance is paramount; therefore, electrical work must be carried out by qualified individuals who understand these codes and their implications, ensuring not only compliance but also the safety of end-users and their environment.