Where there is only one elevator, within how many seconds must it automatically transfer to standby power after normal power failure?

The correct response indicates that, in the event of a normal power failure, an elevator must automatically transfer to standby power within 60 seconds. This requirement is critical for ensuring safety and accessibility in commercial buildings.

Elevators serve as essential components in multi-story buildings, providing convenience and accessibility, particularly for individuals with disabilities or those transporting goods. In the event of a power failure, it is crucial that the elevator does not remain inoperable for an extended period. Transferring to standby power swiftly, within 60 seconds, ensures that any individuals trapped inside the elevator can be safely evacuated or that normal operations can resume as soon as power is restored.

This timeframe reflects industry standards aimed at minimizing disruption and ensuring a quick response during emergencies. Standards set forth by codes such as ASME A17.1 (Safety Code for Elevators and Escalators) guide these requirements, highlighting the importance of maintaining operational elevators for building safety and functionality during unexpected power outages.

In contrast, the other mentioned time frames—15, 30, and 90 seconds—do not meet the established safety and operational standards, which prioritize a balance between prompt action and the technological capabilities of the systems in place.