Elevator Surge Protection

Elevator Surge Protection

Created by: Glen Zhu | Updated Date: September 28th, 2023

Surge Protection for Elevator

Today’s increased reliance on very sensitive electronics makes surge protection an important topic for Elevators, Dumbwaiters, Escalators, Moving Walks, Platforms Lifts and Stairway Chair Lifts.

Do Elevators need Surge Protection?

A high-rise building with elevators should I inquire about surge protection? Elevator manufacturers and service companies on the planet and they tell us unequivocally it’s a good idea to have extra surge protection

Everyone knows the fear of being stuck in an elevator. The right surge protective devices (SPDs) can help to prevent VFD and control board failures so that elevators keep running during storms and surges. Preventing elevator failure – especially for high-rise buildings – keeps everyone at ease.

How to protect your Elevator System and all the associates components like Electrical Panelboard, Elevator Controls, Motors, Variable Frequency Drive (VFD), Safety Interlocks, Charge Controllers, Fire Curtains and other sensitive electronics.

Surge protection is a cost-effective solution to prevent downtime, improve system and data reliability and elimination of equipment damage due to transients and surges for both power and signal lines. It is suitable for any facility or load (1000 volts and below).

Surge protection considerations during elevator modernisation

Advances in elevator technology have been critical facilitators of the high-rise structures that define our urban skylines. However, upgrades in elevator safety, robustness, quality, space efficiency, and performance are needed to support infrastructure development and meet societal needs. So it is importance of opting for the right Surge Protection Device (SPD) to reduce unnecessary down-time.

Elevator modernisation can feel like an expensive and time-consuming undertaking. Before embarking on a modernisation project, a thorough survey is undertaken to assess the current performance of the system. Once armed with this information, an assessment of whether a modernisation is necessary and, crucially, whether it makes business sense can begin.

One of the most important considerations should of course be the safety of the passengers, maintenance personnel and the lift system. A more modern, safer elevator that complies with the latest standards and offers improved reliability is clearly the desired outcome. However, an important safety consideration, that is often overlooked, is the effectiveness of the system’s SPD.

Reducing down-time and maintenance costs

Elevators typically have service lives of over 20 years, but during this time their performance can decline, leading to increased maintenance costs, increased energy usage and the risk of down-time.

Modernisation can make elevators more energy-efficient and reduce energy costs by feeding otherwise wasted energy back into the building whenever the elevator is travelling in an out of balance direction, rather than releasing it in the form of heat through braking resistors.

However, as the hardware and software used in elevator applications has advanced, this has brought about an entirely new set of problems and maintenance considerations.

While this hardware and software is more reliable than ever before, it is also highly sensitive to fluctuations in power surges.

High voltage surges are normally covered by surge protectors. However, traditional SPDs do not account for low level transient surges that can occur countless times a day, exaggerated by VSD usage. Don’t let the name fool you – these transient surges in the sine wave are very damaging to electrical equipment, as the additional peaks and troughs in the sine wave cause confusion to sensitive devices and machines.

This can cause recurring random failures, lockups and deprogramming, such as those experienced by Human Machine Interfaces (HMIs) used in Destination Despatch systems on each floor. So, to protect the electrical control system, the VSD and lift controller from transients, a more sophisticated transient protection system is needed. Downtime and maintenance can be eliminated if the right surge protection such as LSP is in place.

Are Elevators Susceptible to Power Surges?

Power surges are not common but they do happen on occasion and they can affect commercial and residential elevators.

Power surges often occur when the line voltage rises above regular voltage. Surges can also occur in conjunction with power outages, even though surges are basically spikes in electrical currents. However, surges often have a greater tendency to trip out protection features more so than brown-outs or power fluctuations.

Typically, elevators will restart after power surges or power outages, but there are factors that can keep the power restarting.

If the power goes off then goes back on within a few seconds, the elevator power should go back on as well.

The type of elevator can also determine how the elevator responds to a power surge. Some older elevators have less components, which are less sensitive to power variations. The older elevators also tend to have less power production features. This means it make take a larger power outage than a typical power surge to shut down the elevator.

Newer elevator systems are a little different in that they often offer more power protection. Most newer-model traditional elevators feature motor drives equipped with minimum and maximum input voltage detection. This means at a certain percent variance, the motor drive will trip out to protect the elevator and the motor.

Many newer elevators will include other safety features like emergency battery-powered lowering systems, emergency automatic interior cab lighting, emergency alarms and emergency start and stop buttons. All commercial elevators should also have working intercom systems.

Surge Protection for Lifts

Lifts are used to transport people and goods in private and commercial buildings.

Hydraulic lifts are frequently used for low lifting heights instead of counterbalanced cable lifts. The speed of passenger lifts starts at about 1 m/s and increases de- pending on the building (medium-sized buildings / multi-story buildings up to 8 m/s and skyscrapers up to 17 m/s). Goods lifts have transportation capacities of up to 5 tonnes.

Lifts fulfill several functions such as:

  • Smooth starting and stopping controlled by a frequency converter
  • Traffic optimization measures (e.g. no stop in case of full load, priority rides, behavior of lifts in case of fire)
  • Energy-saving functions that switch off the cabin lighting and ventilator when the lift is empty or immobile
  • Power input function (the kinetic energy generated by goods transport to the ground floor and empty rides to the top floors is fed into the grid)

These functions require highly sensitive electronic systems.

Lift manufacturers take various measures to reduce injection into the lift cabling/technology to an acceptable level.

However, whether a metal and, therefore, shielding distribution board, the type of cable or the way cables are routed, these measures cannot prevent conducted transient over-voltages from damaging the lift.

The peripheral units of lifts such as floor panels or floor displays are connected to prewired plug-in connecting cables.

Thus, surge protective devices are only required for the mains connection, the telephone line, and if there is one, the fire alarm system (Figure 1).

Figure 1 – Surge protective circuit for a lift

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Reliability in surge protection!

LSP’s reliable surge protection devices (SPDs) are designed to meet the protection needs of installations against lightning and surges. Contact our Experts!

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