NIST Time|NIST Home|About NIST|Contact NIST

HomeAll Years:AuthorKeywordTitle2005-2010:AuthorKeywordTitle

Elevator Controls.


pdf icon Elevator Controls. (31585 K)
Bukowski, R. W.; Fleming, R. P.; Tubbs, J.; Marrion, C.; Dirksen, J.; Duke, C.; Prince, D.; Richardson, L. F.; Beste, D.; Stanlaske, D.

NFPA Journal, Vol. 100, No. 2, 42-57, March/April 2006.

Keywords:

elevators (lifts); escalators; rescue; building design; fire departments; ASME A17; NFPA 13; fire codes; high rise buildings; evacuation; sprinklers; smoke control; hositways; design applications; pumps; doors; emergencies; training

Abstract:

It is important that all parties, from rescue personnel to building designers understand the intent of the fire service operation provisions of ASME A17.1, Safety Code for Elevators and Escalators. The development of the passenger elevator is tied directly to the emergence of tall buildings. While various types of freight lifts were found in warehouses and factories before the advent of the high-rise, these were considered too dangerous to move people. In 1854, however, Elisha Graves Otis demonstrated an automatic safety brake that changed the landscape. Within a few years, his steam elevators had eliminated one of the major limits to building height. But, while elevators proved to be one of the safest forms of transportation, there were instances where people were killed while using elevators during building fires. Heat sometimes activated call buttons bringing cars to the fire floor where smoke prevented the doors from closing (light beams are in modern day elevators to detect people in the doorway) and water in the shaft sometimes shorted out electrical safety devices or may have caused failure of braking systems. Thus, the use of elevators for occupant egress or fire department access was discouraged. In 1973, the elevator industry developed a system that recalls elevators and takes them out of service if smoke is detected in the lobbies, machine room, or hoistway. Mandated in the American Society of Mechanical Engineers (ASME) A17.1, Safety Code for Elevators and Escalators,1 for all automatic passenger elevators, this system involves two distinct phases of emergency operation.