What is the maximum duration for which an emergency generator should provide power?

The maximum duration for which an emergency generator should provide power is typically eight hours. This duration is in accordance with many building codes and standards, including those set by the National Fire Protection Association (NFPA) and the International Building Code (IBC). The eight-hour timeframe is designed to ensure that emergency power systems can sustain critical functions for a sufficient period during an emergency situation, such as evacuations or during the restoration of main power supplies.

Emergency generators are crucial for maintaining essential services and safety systems—such as fire alarms, emergency lighting, and communication systems—when normal power is lost. While some generators can run longer under ideal circumstances, they should ideally be tested and expected to perform adequately for at least eight hours, balancing operational needs with the limits of fuel, maintenance, and system reliability.

This duration allows not only for immediate response actions but also provides a reasonable buffer before connection to an alternate power source or the restoration of regular power. Understanding this requirement is essential for ensuring that all safety protocols are met during emergencies in high-rise buildings.