What is the required minimum capacity for a secondary power supply to operate a fire alarm system under non-alarm conditions?

The correct choice regarding the required minimum capacity for a secondary power supply to operate a fire alarm system under non-alarm conditions is rooted in the National Fire Protection Association (NFPA) standards, particularly NFPA 72, which governs the installation and use of fire alarm systems. Under these standards, secondary power supplies must be capable of providing power for a minimum of 24 hours during normal (non-alarm) conditions.

This requirement ensures that the fire alarm system remains functional and can effectively monitor conditions even after the primary power source fails. The inclusion of a time period slightly over 24 hours reflects the need for extra capacity that appreciates various factors such as maintenance and unexpected circumstances that could affect system performance.

Choosing this option acknowledges the necessity for preparedness and resilience in fire safety protocols. It also emphasizes the importance of having robust backup systems to support fire safety infrastructure in an array of scenarios, ensuring consistent operation.