for user update on Elevators

1. TECHNOLOGY
Elevator Modernization
The pros and cons of new technology in multi-level condos.
By Ray Eleid, PEng, MBA
Typically, elevator companies are not early technology adapters. They have traditionally
chosen robust and proven technologies in lieu of fads and cutting-edge systems because
elevators are required to operate for a long time and technological mistakes are costly –
both in terms of maintenance and of customer relations. This is a good approach for both
contractors and condominium corporations. While technology is changing at a rapid pace,
its benefits must always outweigh its façade and hype.
There are three main operational areas where the benefits of new technologies should be
considered: repair, modernization and maintenance.
Repairs or Minor Upgrades
Elevator contractors often suggest repairs or minor upgrades to reduce liabilities or
improve the performance or reliability of your elevator equipment. When initiating these
upgrades, consider newer technologies that will add benefit to your equipment and
passengers.
Old Technology
Mechanical safety edges. Elevator technicians are often surprised to see mechanical
safety edges in buildings today because of the potential liability these edges cause. The
mechanical safety edge must make contact with an object before retracting the door and,
depending on the object (person or obstacles), the damage to the door equipment can be
significant, decreasing its reliability and increasing maintenance costs.
Door operators. Most door operators installed in buildings today are based on open-loop
systems. This means that door operator controls are blind to what the door is doing or
how well it is operating. The door control is equipped with switches that dictate door
behaviour. Once the door switch is activated, the door motor slows down or speeds up.
New Technology
Infrared door detectors. These detectors can “see” obstacles to door movement before
the door operates and can also increase the performance of the elevators. Infrared door
detectors come in two-dimensional and three-dimensional designs. Two-dimensional
detectors allow for horizontal and vertical detection and three-dimensional systems also
allow for depth, detecting objects near the door.
Closed-loop door operators. True closed-loop systems are fed information on a constant
basis. The door controls speed up or force the door to close depending on the feedback
from door behaviour. The benefit of such systems is increased reliability, especially in
situations when there is dirt in the track or there is a stack effect in a building on cold
days. Since elevator door problems account for roughly 80 percent of callbacks, this
smart technology upgrade is a worthy one to employ.
Modernizations
The elevators in many older condominiums are approaching the end of their life cycles
and modernization will soon be required. As such, making use of advances in technology

2. is prudent and cost-effective. Not all modern equipment is effective, however. Buyers
should beware. Purchasing less expensive equipment may actually cost you more over
the life of the equipment in maintenance costs and a shorter life span.
Old Technology
Relay logic controls. These controls use electromechanical relays to dispatch elevators
and to perform the logic required to move them efficiently and effectively in a building.
However, the electrical contacts and relays in an electromechanical system can wear
rapidly, become dirty or misaligned, affecting the reliability and consistency of the
elevator performance. Good maintenance programs can reduce problems with these
systems but when problems do occur, they can be intermittent and difficult to isolate. As
Murphy’ Law dictates, consistent problems arise at the most inconvenient time.
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Motor generator drive. Many older highrise elevator control systems have an open loop
system, equipped with a Ward Leonard, variable-voltage, direct-current type of drive,
with no positive position or feedback controls. This very popular system affords
acceptable car speed control. However, compared to modern elevator control systems,
this type of drive is both antiquated and extremely inefficient in terms of energy
consumption and general maintenance.
Two speed controls. This active-current (AC) motor system relies on the high-speed and
low-speed windings on the motor to control the speed of the elevator. A bank of resistors
is then used to somewhat soften the transition speed and improve the quality of the drive.
This system is very popular in lowrise, slow-speed buildings.
Single-speed controls. This AC motor relies heavily on the brakes to stop the elevator.
There is no variable speed in this system and, as such, the stopping is rough and the
levelling accuracy is very difficult to achieve.
Zone dispatching. Most condominiums with older vintages of equipment are supplied
with elevators that service a zone, a group of floors served by the same elevator. For
example, a 12-storey building may have Zone 1 servicing the P1 and G levels, Zone 2
servicing floors 2 to 6 and Zone 3 servicing floors 7 to 11. As long as one elevator is in a
zone, other elevators usually do not respond to hall calls in that zone. As such, passengers
in the lobby sometimes get frustrated when they see an elevator on the third floor that is
not responding to their hall call because there is an elevator on the P1 level.
New Technology
Microprocessor logic. These systems use computer circuits and logic to operate the
elevator effectively. A huge benefit to using microprocessor logic-driven systems is that
they are virtually maintenance-free and remain reliable if the equipment supplied is
proven and installed properly. Elevator passengers benefit from reliability as well as
better performance and more consistency in the behaviour of the elevator.
Closed-loop VVVF. Variable voltage variable frequency (VVVF) drives for AC motors
have been around for a long time and the technology has improved greatly over the years.
The most recent high-tech products are dubbed “vector control systems,” designed for
induction motors or permanent magnet synchronous motors, a type of brushless direct-
current (DC) motor system. If these motor options don’ seem attractive, designing an AC
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motor as a “bolt-on” replacement for the DC machine on an existing gearbox is relatively
simple on a lower-speed elevator. This option is much lower in cost and risk.

3. An open-loop system does not take advantage of readily available technology that tells
the elevator controls what the elevator motor and cab are doing. This means the elevator
drive creates an acceleration and speed profile pattern but does not know exactly what the
motor or the cab are doing. Hence, the drive cannot adjust for variables such as
temperature, slip, over voltage and wear. What does that mean? Closed-loop systems
mean more accurate stopping and ride comfort all the time. Also, the cost benefit of such
systems is very attractive.
Bidding, wait time and artificial intelligence dispatching. These different technologies
and strategies for dispatching are superior to older systems. They can judge potential wait
time that passengers may experience and dispatch elevators in an effort to reduce the
maximum wait time. Other systems memorize the dispatching algorithms and learn to
predict future calls. For example, if at 10 a.m. a high number of calls are placed on the
third floor three days in a row, the elevators will be waiting on the floor in anticipation of
calls on the fourth day. This obviously results in shorter wait times and happier
passengers.
Maintenance
The Internet has created new possibilities with regard to maintenance. Condominium
owners and managers can benefit greatly from computerized maintenance records,
available 24/7 online. This information has always been available to elevator contractors
in the past and was requested by clients on an ongoing basis. However, dedicated Internet
sites now allow the property manager to see what the elevator contractors see and share
the information and common goal of improving the elevator service. These systems have
inspired openness and access in the customer-client relationship.
While property managers have implemented their own systems to manage client needs,
these elevator maintenance systems can also be made available to condominium
directors, providing information related to elevator efficiency and availability,
maintenance performed, call-back details and maintenance history.
In summary, technology is changing all around us. Regardless of a condominium’ needs
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and the age of its elevators, technology can help property managers and directors achieve
their goals to create greater elevator efficiencies and reliability.
Ray Eleid, PEng, MBA, is the director of strategic development at Solucore Inc., an
independent elevator consulting firm located in Toronto and Mississauga.
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CM Condominium Manager Magazine - Fall 2003