By Richard E. Avallone
Photos by Dennis Walus
During the 30+ years that I’ve been teaching elevator safety to firefighters and first responders, I am asked certain questions on a somewhat regular basis. One of these questions concerns the subject of elevator power supply. A question generally asked is, “Will the emergency stop switch located in the elevator car or the stop switch in the pit area or on the elevator car top area shut off the power to the elevator?” The answer is NO. These switches open a circuit, but they do not disconnect power from the elevator, and there is no guarantee that an elevator could not move suddenly and without warning. These switches are for use of the elevator repairman or the elevator inspector. They are not designated nor are they engineered or designed to remove power from the elevator. The only designated location to remove electrical power from an elevator is the main line disconnect switch, which is located in the elevator machine room. The main line disconnect switch, once placed in the “OFF” position, should also be locked out and tagged out on all responses to elevator incidents (photo 1). There are no acceptable shortcuts or exceptions to this practice.
(1) The main line disconnect for an elevator (left) is in the “OFF” position to prevent the elevator from moving. The switch on the right controls lights and ventilation fan for elevator car. It can remain on for the occupant’s comfort.
Why do firefighters attempt to cut power to an elevator by operating car top or pit switches (photos 2, 3)? Because they think it’s faster and easier than gaining access to a machine room to operate a mainline disconnect. Firefighters must not allow laziness, complacency, or dangerous past practices jeopardize their safety and the safety of occupants trapped in a stalled elevator. Shutting down the main disconnect in an elevator machine room is the only way to be positively certain that the power is off; anything else is a gamble. Removing the power supply at the main disconnect switch is consistent with acceptable operational procedures throughout the fire service and elevator industries.
Scenario: You, the company officer, and your engine company respond to a reported house fire. You arrive on scene and discover a smoke condition in the kitchen, clearly caused by the fluorescent light fixture located on the kitchen ceiling. The ballast in the fixture has melted and caused some burning and discoloration of the ceiling materials. The homeowner advises you that he has shut off power to the house at the main circuit breakers. You investigate further and discover that there is no further threat of fire from the electrical system of the house. Which response would be your next course of action regarding the house and the homeowner?
A) Restore power to the home and instruct the homeowner not to turn on the light switch to the florescent fixture in the kitchen so the homeowner can use the kitchen appliances.
B) Restore power to the house and leave the circuit breaker, which provides power to the entire kitchen, in the “OFF” position.
C) Call for an electrical inspector to verify your assessment of the electrical system and to determine a safe course of action regarding power supply to the house.
If you, as the company officer, were to select answer A, then you would be operating in a consistent manner with a person that would rely on an elevator pit “stop switch” or car top “stop” switch for the safety of your personnel or—in the scenario above—the safety and well-being of the homeowner and family. For the scenario, this would be the wrong decision and course of action for any company officer. However, the comparison of the power removal example is accurate. Why would you want to rely on a “stop switch” located anywhere on an elevator for yours and your personnel’s safety? These switches may not be as reliable or constructed as well as a typical household light switch, and this applies to all types and styles of elevator stop switches. On average, approximately 10 percent of these “stop switches” fail on inspection, and when they fail, they fail in the run position (bypassed awaiting replacement), which means they will not stop an elevator from running unexpectedly, causing injury, loss of limbs, or lives.
(2) The car top switch (3) The car and pit switches. They are not are not substitutes for shutting off power at the main disconnect.
Opening elevator shaft way doors without turning off the power is another area of risk for firefighters. The use of elevator shaft door release keys with the mainline disconnect switch in the “ON” position can result in an extremely painful hand injury. Remember that shaft way doors open and close under the power of elevator car doors that are driven by an electric motor which operate levers, pulleys, and/or a sprocket assembly. If the elevator car floor is located within 18 inches of a hall floor landing, there is a good chance that a mechanism on the door assembly, known as a clutch, will engage the shaft doors and open the car and shaft doors in unison, as they normally should. If you respond to a report of someone trapped in a stalled elevator and you fail to shut off power to the elevator, when you insert and operate the shaft door release key and begin pulling the shaft doors open, the elevator is most likely going to respond by opening the car doors, which in turn opens the shaft doors. Now consider that your fingers are on that shaft way key; the doors can open so fast and unexpectedly that you may not have time or the presence of mind to let go of the key before your fingers are crushed between the key and the door frame of the hallway floor landing (photo 4).
(4) Doors that open unexpectedly can crush fingers between a shaft way door key and the floor landing door frame.
Elevators are one of the safest modes of transportation, but they have the power to inflict serious injury if their power is not properly disconnected. Remember, switches and devices that open safety circuits are not failsafe; they have and will malfunction and may be the reason why the fire department is called to release occupants from a stalled elevator. Fire service and elevator Industry professionals know that there are no acceptable shortcuts or exceptions to shutting off power at an elevator’s main disconnect.
Richard Avallone is a 30-year fire service veteran serving as a firefighter and training officer for the Pompano Beach (FL) Fire Department. He began his career in the elevator industry as a repair and installation technician in New York City, where he worked for 10 years. He continued installing and servicing elevators in Florida in 1985. Avallone conducts elevator safety and rescue training programs throughout North America.