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Industrial drives bring hydraulic
elevators into the next level –
Faster comissioning, lower energy costs and noise emissions
By integrating a SINAMICS S120 drive to the hydraulic system the Italian elevator specialist Omarlift Srl.,
­supported by the Solution Partner Telmotor S.p.A., developed a plug-and-play elevator system, which reduces
installation time, noise and energy consumption. The energy costs are reduced by up to 50 percent – simply
because the motor only runs when hydraulic power is actually needed, making also the system quieter, more
precise and eliminating the necessity of installing a cooling system.
Experts recommend drive-based hydraulic systems
A simple principle opens new possibilities
Ongoing demographic change and an increasing quality
of life is driving the need for barrier-free and sustainable
­living space – and therefore for intelligent elevator solutions
to upgrade existing buildings. A good example for this
occurred close to Milan, Italy, when the owner of a fivestory multi-unit apartment building decided to add an ele­
vator to his building. A small gap on the outside, without
enough space for a machine room directly below or above
the shaft, was the only suitable place to install the lift.
The reason for this recommendation is clear. In a valvecontrolled hydraulic system, the motor runs continuously
at high speed – regardless of the actual requirements.
Its energy consumption, noise level, and heating up are
­cor­­­­­res­pondingly high. Furthermore, this heat must be
removed by an energy-intensive and noisy cooling system.
By adding a frequency converter these problems are solved,
now the pump turns only as much as re­­quired. This is a
simple, but highly effective principle. If the elevator travels
at partial speed, the pump turns at partial speed, if the
­elevator stops, the pump stops, if the elevator descends,
the pump reverses. The capa­bility to reverse the pump
opens new possibilities for feeding back energy into the
grid or for storing it and eliminate power peaks. “It is up
to the market to say if and when it wants this f­ eatures”,
adds Marco Fadini, ­Operation Manager at Omarlift.
The company MAS Srl was hired to install the elevator, and
Mr. Fabio Imprenti, the head engineer, recommended that
a hydraulic elevator be installed. His recommendation was
based on the infrastructural limitations, lower in­­stalla­­­tion
and maintenance costs.
Mr. Mordini, president and sales manager of Omarlift, an
Italian elevator hydraulics specialist, recommended MAS to
use a drive-based hydraulic system to make its s­ ystem as
precise, quiet and energy efficient as possible.
Shaft
Outside
Elevator
cabin
Mneeded
nneeded
Machine room
Building walls
Machine room
Mestimated
nestimated
Shaft
Elevator
cabin
nconstant
Cooling system
Pipes, radiator and noise are eliminated
A further advantage of this solution is that it can do more
with less “Instead of a 11 kW motor, all we need is a 7.5 kW
one,” says Imprenti. “This reduces the price and size.”
­Additionally, the system does not require a cooling system,
which significantly reduces the noise level, investment and
operating costs. The cooling system is made of an additional pump, pipes and a radiator, which is often placed
outside of the building. “The noise difference between a
valve-controlled (64 dB) and a drive-based solution (60 dB)
might seem not so big, but taking into consideration that
the radiator’s noise is generated outside the building –
often near bedroom windows – the difference is clear”
adds Fadini. This solution is therefore highly recommendable for residential areas, hotels, hospitals, offices, airports
and shopping centers.
Energy consumption per up and down travel (two floors)
Energy consumption [kJ]
350
300
250
200
150
100
50
0
-10
10
30
50
70
90
110
130
150
170
Consecutive travels
Valve based
(cooling OFF)
Siemens AG
Digital Factory
P.O. 31 80
91050 Erlangen
Germany
Valve based
(cooling ON)
Drive based
(no cooling needed)
Plug-and-Play elevator due to free-programmability
The heart of the solution is a SINAMICS S120 drive that
­controls the pump. The Drive Control Chart program was
developed with the support of T
­ elmotor S.p.A. and has two
main functionalities: the first one is to control the car’s
­position, speed and acceleration, taking the load and oil
temperature into consideration – maximizing accuracy and
comfort and the second one is to auto-tune the elevator by
moving it, making measurements, calculating and setting
the ideal parameters automatically. Fadini describes the
system: “The auto-tune ­functionality makes our system
­easier and faster to install on-site, it is a plug-and-play solution.” He adds; “The principle of using frequency converters
in our hydraulic systems is not new for us. However with
other suppliers it was not possible to implement, and protect, such complex programs” A further advantage of the
SINAMICS S120 is its integrated and freely programmable
Webserver which allows remote diagnostics of the drive.
50 percent less energy consumption
Omarlift’s engineers thoroughly tested the energy consumption of the system. The results are impressive: By
using the drive-based solution, and being able to eliminate
the cooling system, the energy demand was reduced by
approximately 50 percent compared to the valve-controlled
one. “Not only is this an enormous step forward ecologic­
ally,” Fadini adds, “it also offers clear economic benefits.
This technology makes hydraulic elevators more attractive
than traction elevators in buildings up to five stories high,
due to lower investment, operating, and maintenance
costs. In most cases, the additional cost of the frequency
converters is covered from the very beginning by the downsizing of the motor, elimination of soft starter, expensive
control valves, cooling system and installation of pipes.”
Subject to change without prior notice
Article No: E20001-XXXX-XXXX
Dispo 21500
SCHÖ/1000022620 V6.MKAPPL.WES
SB 0915X.X
Printed in Germany
© Siemens AG 2015
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