The secondary supply must be capable of operating a fire alarm system for how many hours under maximum normal load?

The requirement for the secondary supply in a fire alarm system is to ensure that it can operate effectively during a power outage or failure. This is crucial for maintaining the safety of the occupants and ensuring that the fire alarm system remains functional in emergencies. According to industry standards and regulations, the secondary supply must be capable of sustaining the fire alarm system under maximum normal load for 24 hours. This duration allows the system to remain operational during extended periods without main power, thereby providing sufficient time for response and intervention in case of a fire event.

In fire alarm systems, the secondary supply, often in the form of backup batteries or a generator, is designed to kick in when the main power is disrupted. A requirement of 24 hours reflects a common standard aimed at ensuring reliability in various emergency scenarios. Maintaining operations over this specified time frame helps ensure that alarms will be sounded and that any monitoring functions can continue without interruption, thus safeguarding lives and property.