Can a smoke alarm be connected to a switched outlet?

Connecting a smoke alarm to a switched outlet is permissible, but it comes with an important stipulation: the smoke alarm must not lose primary power. This is crucial because smoke alarms are life safety devices that need to operate at all times, particularly during an emergency. If the outlet is controlled by a switch, there is a risk that someone may inadvertently turn off the alarm or the outlet, disabling the smoke alarm when it's needed the most.

The requirement that a smoke alarm must maintain power ensures that it is always operational, particularly during times when a fire might occur, such as at night. By adhering to this guidance, you help ensure the reliability of the smoke alarm system, enhancing the safety of the occupants in the building.

The other options reference conditions that are either impractical or inherently unsafe, highlighting the importance of always having smoke alarms operating without the interference or risk of being turned off.