The Impact of Fire on Elevators in Tall Buildings: Protocols and Safety Measures

In the event of a fire, elevators in tall buildings play a critical role in ensuring the safety of occupants. These systems are designed with advanced protocols to prevent further complications and ensure that they can be used correctly by emergency personnel. Understanding how elevators behave during a fire is crucial for both building managers and residents.

Understanding Fire Service Elevators

Elevators are required to have ldquo;Fire Service.rdquo; Depending on the type of building and the jurisdiction, there are typically two phases of operation: Phase I and Phase II. Phase I is specifically designed to recall the elevator to the main egress floor or an alternate floor when the elevator's smoke detectors are triggered. This ensures that the elevator is in a safe zone where it can be used by emergency personnel.

Phase I: Smoke Detection and Recall

During a fire, if the elevator enters Phase I, the system will recall all elevators to the main egress floor or an alternate floor. This is typically the ground floor or the floor immediately below if higher elevators need to be used for quick access. Once the elevators are recalled, they can no longer be used by occupants unless they are equipped with a ldquo;fireman lock-out key.rdquo; This is a special key that allows emergency personnel to take control of the elevator.

"h2>Phase II: Emergency Use by Fire Department After the Phase I recall, a special key is required to switch the elevator to Phase II. In this mode, the elevator can be used by the fire department for emergency operations. To close the elevator doors, the button must be held in. If the button is released, the doors will reopen. The system requires the door close button to be held until a full closing is achieved to ensure that the doors close properly. Once the doors are fully closed, the elevator can move to the desired floor. For the safety of passengers, the doors will remain closed. If the door open button is pressed and held, the doors will open fully at the destination floor. The doors must be held open to ensure complete opening. If the button is released, the doors will close immediately. No other buttons can be used to call the elevator to a different floor from outside the elevator. This ensures that the elevator can be used by emergency personnel without interference.

There is an additional safety feature known as ldquo;shunt trip.rdquo; Shunt trip is activated by heat sensors in the elevator machine room. If the machine room gets heated up to a certain point, the elevator is sent down to the egress floor, the doors open, and the shunt trip trips the main line disconnect, removing power from the unit. This is a crucial safety requirement if there are fire sprinklers in the machine room.

Control and Safety During a Fire

In most high-rise buildings during fire, elevators are placed under the control of the fire department using a special key. Building managers or maintenance personnel will usually have the key. This ensures that emergency personnel can use the elevators safely and efficiently.

It is worth noting that Michael's explanation is correct with one exception: a fireman elevator may not stop completely but rather keep moving to keep the passengers safe and provide clear pathways for emergency personnel. This is in line with ensuring that the fire department has the necessary tools and clear access to perform their duties without delays.

Understanding these protocols is essential for building occupants and emergency personnel. Proper operation of fire service elevators can be a lifesaver in the critical moments of a fire emergency.