What is the function of Phase I in elevator operation during emergencies?

The function of Phase I in elevator operation during emergencies is to call elevators to a pre-determined level, usually the ground floor or a designated safe area for evacuation. This is a critical safety feature designed to prevent elevators from becoming traps in a fire or emergency situation. By moving the elevators to a specified location, emergency personnel can ensure that they are available for use only when it is safe to do so, managing the risk to occupants and responders.

When Phase I is activated, it typically involves the elevators being controlled by the fire alarm system, which overrides normal operations to prioritize safety. This prevents the elevators from being used by building occupants who may be in danger and ensures that emergency responders can access the building safely.

In contrast, other options focus on functions that do not specifically align with the primary purpose of Phase I. For example, opening all elevator doors would present safety risks; engaging fire alarms is part of the broader emergency response system rather than specific elevator operations; and activating emergency lighting serves a different purpose related to visibility and safe evacuation routes during an emergency.