Which system must have standby power capable of operating for 24 hours during normal operation?

The requirement for standby power capable of operating for 24 hours during normal operation is applicable to all types of systems listed. This is often a critical specification in fire alarm and emergency communication systems to ensure continuous operation in the event of a power failure.

Each system—whether it's a local system, household system, or remote station system—must maintain functionality to ensure safety and compliance with code requirements. For instance, a local system utilized in commercial buildings must remain operational to alert occupants in case of an emergency. Likewise, household systems serve individual residences, requiring reliability for family safety, and remote station systems ensure that operations are maintained even when they are not directly monitored onsite.

Having standby power for at least 24 hours ensures that these systems can provide alerts or notifications in emergency scenarios, which is particularly essential for life safety systems. This standard demonstrates a commitment to safety and reliability across various applications.