Lerch Bates Inc. Building Insight

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Elevator Emergency Operations

I frequently encounter misunderstandings regarding the various emergency operations that an elevator can, and in some cases, is required to perform. The most commonly confused operations are Firefighters’ Service and Emergency Power operations. Let me explain the differences.

First, note that Firefighters’ Service and Emergency Power operation are completely independent of each other, though it is not impossible for both of them to be in use in an emergency situation. In most instances when Firefighters’ Service is activated, full electrical service is available to the elevator systems. Emergency Power operation is only activated by a loss of normal electrical service to the elevator systems.

Firefighters’ Service is required on virtually all elevators.  When I first entered the elevator business I remember referring to this as Commandeering operation.  I mention this because that is exactly what Firefighters’ Service Phase II is as complete control is turned over to the operator. On Phase II operation an emergency personnel user can enter a call or cancel a call to any floor level served by the elevator.  Any call entered can be cancelled immediately by pushing the call cancel button.  This allows for redirection to another location at a moment’s notice.  The user also has complete control of the doors, which will not open unless the Open Door button is held down with continuous pressure.  If the button is released before fully open, the doors automatically close.  This way, if a fire is discovered in the elevator lobby, simply releasing pressure from the door close button will cause the doors to close.  Likewise, the doors will not close until the door close button is held continuously and the door is completely closed.  So if the firefighter needs to get back out at the floor, the doors will automatically reopen when the door close button is released if the doors are not fully closed.

But before Phase II can be activated, Firefighters’ Service Phase I must be activated.  Phase I is initiated by either, A) a key switch located in the elevator lobby or in the Fire Command Center (frequently referred to as the FCC Room), or B) by a smoke sensor in an elevator lobby, in the elevator machine room, or in the elevator shaft, if a detector is present.  Activation of Phase I operation returns all cars immediately to the primary floor, unless the detector at the primary floor is the one that activated Phase I operation.  If this detector is activated, the elevators return to the alternate floor, typically the next most logical floor for firefighters’ access.

Emergency Power operation is normally only required in a high-rise buildings, though it can be provided on any elevator, and requires that power be provided with power to serve every floor of the building for access by emergency personnel.  However, most elevator systems provide the necessary control and circuitry to allow any elevator in the building to operate on emergency power.  The elevator control system receives a signal that tells it that it is no longer operating on normal full power but that only limited amount of power is available.  The control system then determines an order in which the elevators return to the main floor and take themselves out of service.  This evacuates any passengers that might be on the cars.  When all cars have returned to the main floor, one car remains in service.

In both Firefighters’ Service and Emergency Power operations, all cars are typically returned to the main floor, but the similarities end there.  Both operations can be in affect if the necessary conditions are present.  However, in Firefighters’ Service, any or all cars can be operated on Phase II if full electrical power is available.  If Emergency Power operation is activated when the elevators are on Firefighters’ Service operation, only one car is capable of running since limited electrical power is available.

While both operations are necessary, you can see that they provide different functions for different scenarios.