What Happens to Elevators After A Power Failure?


Electric energy changes into mechanical energy and your elevator cabs move up or down based on your command. With no power, your elevator equipment is of no use. From extreme weather conditions to technical grid and distribution problems – many factors attribute to a sudden power failure. Premier Elevator Cabs explains what happens when your power supply goes off suddenly, damages it can cause, and ways to avoid them.

Things You Experience

#1. Convenience

In normal condition, power failure gives a small jerk to the elevator cab and it comes to a standstill, but when the elevator cab is in between two floors, it doesn’t stop there. Its momentum pushes it to the next floor where the door opens, and you can easily walk out. Elevator cab companies engineer the movement and break mechanisms in a manner to ensure maximum convenience during any sudden power failure.

#2. Safety

There is a small power backup that comes to your rescue when there is an abrupt power failure. Intercom, alarm bell, lighting bulbs and fans inside the cab keep working to ensure your safety. Contact the maintenance department or helpdesk of your building to seek support if the elevator’s power is not restored and your life is at risk.

Things That Happen Behind The Scene

#1. Elevator SMPS Senses the Power Failure Early

The SMPS (Switch mode power supply) unit converts the 110/230 AC input into 24V,12V, or 5V units as per the requirements of different components of the elevator equipment. Since it’s directly connected to the main power supply, it detects the outage first.

Frequent power failure affects the functioning and efficiency of SMPS. Keeping an electricity backup system can be helpful. It ensures durability and reliability of the hardware and maximum convenience and safety for travelers. SMPS performs a critical role by handling the main power supply and it must be in a good condition. If you happen to notice any problem, you must report it to the elevator service company.

#2. Power Failure Signal Passes on To the Controller System


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The elevator controller accepts the inputs provided and produces intended outputs. It coordinates all the components and their functionalities related to the elevator movement (acceleration and deceleration), speed, door opening speed and delay, lighting, fan, and alarm system. As soon as the SMPS detects the power failure, the same is conveyed to the controller system. It brings the elevator into the power-saving mode and ensures continuity of the essential services like hoisting, light, and alarm systems for passenger’s convenience and safety till the cab reaches a specific floor.

Common Elevator Malfunctioning Due to Frequent Power Failure

Though elevator SMPSs, controllers, and other components are equipped with circuit protection fuses and circuit breakers to handle power fluctuation or flickering, the intermittent issues can cause damage to them and may compromise the safety and convenience of passengers. This can be avoided by having an agile power backup system.

Excessive power inputs also referred to as power surges, can trip out protection features and damage the elevator equipment. To avoid this, you must have a strong earthing system to absorb the extra voltages and electricity.

In extreme conditions after a power failure, if you notice that the elevator is not starting up automatically, do not panic. Confirm whether you have got full power across all 3 phases. If it’s okay, then turn off and on the elevator. The restart works most of the time. If you still don’t get any success, then raise a complaint with the elevator engineering services company.