What is required from a secondary power supply in terms of power transfer during a primary power failure?

The requirement for a secondary power supply to ensure uninterrupted power transfer during a primary power failure is to maintain service without significant delay. This is critical for systems that demand reliability, such as fire alarms, security systems, and essential life safety applications. The stipulation of uninterrupted power transfer within 30 seconds is designed to provide a reasonable balance between operational efficiency and the practical limitations of transfer systems.

This timeframe allows for the secondary power source to engage and start delivering power seamlessly, minimizing the risk of disruption during an outage. Transfer times longer than this could expose sensitive equipment to potential downtime or operational inconsistencies, which could jeopardize safety and functionality. Thus, the specification for 30 seconds reflects industry standards aimed at ensuring continuous operation during power disruptions.