UL 217

These requirements cover electrically operated single and multiple station smoke alarms intended for open area protection in indoor locations of re sidential units in accordance with the National Fire Alarm Code, NFPA 72, smoke alarms intended for use in recreational vehicles in accordance with the Standard fo r Recreational Vehicles, NFPA 501C, and portable smoke alarms used as “travel” alarms.

A single station smoke alarm, as defined by these requirements , is a self-contained fire alarm device that consists of an assembly of electrical components including a smoke chamber, alarm sounding appliance, and provision for connection to a power supply source, either by splice leads or a cord and plug arrangement or containing integral batteries. Possible accessories include a supplemental heat detector, terminals for connection to a remote audible signaling appliance or accessory, and an integral transmitter to energize a remote audible signaling appliance.

Multiple station units are single station smoke alarms that are either interconnected for common alarm annunciation or connected to remote thermostats.