The National Fire Alarm and Signaling Code,NFPA 72-2019,is a lengthy handbook that specifies the “application, installation, location, performance, inspection, testing, and maintenance of fire alarm systems” as well as emergency and fire warning equipment and their components. It has been adopted by federal, state, and local authorities throughout the U.S. as a standard required for the enforcement of fire code regulations, usually with amendments to suit a particular state or city.
A supplement to the Fire Alarm Code explains how fire alarm systems interface with elevator controls. This interfacing is vital to ensure that both are fully coordinated for maximum efficacy. It is also vital to maintain safety by minimizing the possibility of people getting trapped in elevator cars and possibly ending up on the floor where the fire is.
The Code also discusses firefighters’ recall, which was first included in NFPA 72A, Installation, Maintenance and Use of Local Protective Signaling Systems in a section titled Elevator Recall for Firefighters’ Service that, like the Safety Code for Elevators & Escalators, required smoke detectors used to initiate firefighters’ recall to be located in elevator lobbies and machine rooms. The belief was that as long as elevators weren’t in danger from fire – which was determined by the smoke detectors – they could continue to operate and be used by occupants of the building.
Elevator recall design at that time required the smoke detector in the designated lobby to actuate the first circuit and the smoke detectors in other lobbies and the machine room to actuate the second circuit. The two circuits were designed to differentiate signals coming from the different areas of the building to help detect where the fire was.
NFPA 72 has changed a lot over the decades, with regular revisions every three years.
There have been substantial, ongoing changes that relate to smoke detection and smoke alarms, which is clearly vital for elevator recall design.
There have also been changes and additions that relate to circuit and pathway performance designations, general wiring requirements, emergency communication systems, and emergency recall operations.
Emergency recall operations are detailed in Chapter 21, Emergency Control Function Interfaces, and, amongst other things, require all the fire alarm initiating devices used to initiate elevator Phase I emergency recall operations to be connected to required building fire alarm system.
New York Engineers has considerable experience in elevator recall design and our team of professionals constantly updates their knowledge to ensure designs are compliant and technologically advanced.