Page 18 - Energize March 2021

NEWS

Surge protection considerations during elevator modernisation

dvances in elevator technology to any existing AC drive to produce substantial energy savings — savings which can be easily
have been critical facilitators of calculated using the company’s online Energy Savings Calculator tool.
Athe high-rise structures that define However, as the hardware and software used in elevator applications has advanced, this
our urban skylines. However, upgrades in has brought about an entirely new set of problems and maintenance considerations. While this
elevator safety, robustness, quality, space hardware and software is more reliable than ever before, it is also highly sensitive to fluctuations
efficiency and performance are needed to in power surges.
support infrastructure development and High voltage surges are normally covered by surge protectors. However, traditional SPDs do
meet societal needs. not account for low level transient surges which can occur countless times a day, exaggerated by
Elevator modernisation can feel VSD usage. Transient surges in the sine wave are very damaging to electrical equipment, as the
like an expensive and time-consuming additional peaks and troughs in the sine wave cause confusion to sensitive devices and machines.
undertaking. Before embarking on a This can cause recurring random failures, lockups, and deprogramming, such as those
modernisation project, a thorough survey experienced by human machine interfaces (HMIs) used in destination despatch systems on each
is undertaken to assess the current floor. So, to protect the electrical control system, the VSD and lift controller from transients, a
performance of the system. Once armed more sophisticated transient protection system is needed. Downtime and maintenance can be
with this information, an assessment of eliminated if the right surge protection such as the company’s SineTamer is in place.
whether a modernisation is necessary and, Crucially, SineTamer’s frequency attenuation network monitors the frequency, not just the
crucially, whether it makes business sense, voltage. The engineered transient disturbance filter is designed to monitor all 360 degrees of
can begin. the sine wave, making it capable of detecting rapid changes in frequency. This vigilance in turn
One of the most important prevents issues caused by false zero crossings of the sine wave.
considerations should of course be the When approached carefully, modernisation — whether that’s partial or a complete
safety of the passengers, maintenance replacement — can lower repair costs, reduce faults and increase energy savings while improving
personnel and the lift system. A more comfort, efficiency, safety and aesthetics. However, it’s important that facilities’ managers do not
modern, safer elevator that complies overlook the importance of protecting this sensitive equipment from harmful power surges. n
with the latest standards and offers
improved reliability is clearly the desired Contact John Mitchell, CP Automation, john.mitchell@cpaltd.net
outcome. However, an important safety
consideration, that is often overlooked, is
the effectiveness of the system’s SPD.
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 downtime.
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.
For example, CP Automation’s
Magnetek range of elevator products
include drives with in-built regenerative
technology and separate regenerative
“bolt-on” modules which can be retro-fitted

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