Which of the following is a rule for coaxial cable installations under Article 820?

The requirement that the outer shield of the coaxial cable must be grounded close to its point of entry into the building is crucial for safety and performance. Grounding the outer shield helps to protect both the equipment and the individuals using it from electrical surges or lightning strikes. This grounding provides a path for any excess voltage to dissipate safely into the ground, reducing the risk of damage to the cable and connected devices.

Moreover, proper grounding of coaxial cables is essential to minimize interference and maintain signal quality. By grounding the shield, it prevents electromagnetic interference from affecting the signals carried through the cable. This requirement is specifically outlined in Article 820 of the National Electrical Code, which governs the installation of coaxial cables for communication purposes.

Understanding this rule is vital for ensuring that installations meet safety standards and function effectively within a residential environment.