According to the National Fire Alarm Code (NFPA 72), what is required of fire alarm equipment?

The requirement that fire alarm equipment must be listed is crucial for ensuring safety and reliability. A listed fire alarm device means it has undergone rigorous testing and meets specific safety standards established by authorized testing laboratories. This listing guarantees that the equipment has been evaluated for its performance under a variety of conditions, thereby minimizing risks associated with fire alarms, such as false alarms or failures to alert occupants in case of an emergency.

The listing not only confirms that the device complies with the National Fire Alarm Code, but also that it has been manufactured according to recognized standards of quality and safety. This is essential for the integration of fire alarm systems into buildings, as having listed equipment helps ensure compliance with local codes and regulations, and provides peace of mind to both installers and occupants regarding the reliability of the alarm system.

While the other options such as installation by certified professionals, being hardwired, or battery-operated devices may pertain to specific situations or types of installations, they do not encompass the fundamental requirement for fire alarm equipment to be tested and approved for safety and effectiveness, which is what being "listed" signifies.