Must support signaling for 1 hour, conversation for 4 hours during power loss.

• A. Emergency Power Duration
• B. Winding Drums
• C. Restriction Sign
• D. Angle of Inclination

Answer: (A)

The main idea here is emergency power duration—how long the escalator or moving walk’s essential functions must run on emergency power when the main supply fails. In a power outage, it's critical that certain systems keep working: signaling to warn passengers and staff, and a means of communication so people can coordinate a safe evacuation. The requirement stating signaling must be supported for one hour and usable intercommunication for four hours defines the minimum time those critical functions must be powered. That’s why this option is the best fit.

Winding drums are part of the drive and rope/chain mechanics, not about maintaining functions during a power outage. A restriction sign conveys warnings or prohibitions, not the duration of emergency power support. The angle of inclination deals with the physical slope and isn’t about emergency power duration either.