Liquid-Cooled Sinamics S120 Units; General; Design Of The Liquid-Cooled Sinamics S120 Units - Siemens SINAMICS G130 Engineering Manual

Fundamental Principles and System Description
Engineering Information

1.16 Liquid-cooled SINAMICS S120 units

1.16.1

General

The devices of the SINAMICS S120 modular drive system are available in an air-cooled or a liquid-cooled version.
This applies to both, SINAMICS S120 units in Chassis format and Cabinet Modules format.
The fundamental principles of liquid cooling and the liquid-cooled units in Chassis format are discussed in further
detail in this section. The liquid-cooled cabinet units in Cabinet Modules format that are based on the liquid-cooled
units in Chassis format are described in chapter "General Information about Modular Cabinet Units SINAMICS S120
Cabinet Modules".
Liquid cooling allows much more efficient heat dissipation than air cooling. Therefore, liquid-cooled units are more
compact than comparable air-cooled units with the same output power rating. Since the power losses occurring in the
devices are almost fully dissipated via the coolant (see table below), no cabinet fans or only very small fans need to
be installed in the cabinets in which the liquid-cooled equipment is installed (depending on the degree of protection of
the cabinet) in order to dissipate the losses from the converter electronics, busbars, fuses and air-cooled components
such as reactors and filters at the input and output ends. Consequently, the units are very quiet. Due to their
compactness and their very low cooling air requirement, the use of liquid-cooled units is recommended where space
is constrained and/or harsh environmental conditions prevail. Even completely enclosed control cabinets with degree
of protection IP55 can be realized as liquid-cooled systems. With completely enclosed control cabinets with degree of
protection IP55, the heat loss from the electronic circuitry that is transferred to the air (see table below) as well as the
heat loss from busbars, fuses and air-cooled components at the input and output ends such as reactors and filters
must be transferred to the coolant by additional fans installed in the control cabinet that work in combination with air-
to-water heat exchangers.
1.16.2

Design of the liquid-cooled SINAMICS S120 units

Liquid-cooled SINAMICS S120 units in Chassis format are characterized by a high power density and a footprint-
optimised design. They come with degree of protection IP00. The electric power connections for the DC link are
brought out at the top on all units. The line supply connections are brought out at the top on Basic Line Modules
(BLM) and at the bottom on Active Line Modules (ALM). The motor connections of the Motor Modules are on the
bottom of the module. The connections for the coolant (inflow and return flow lines) are located on the bottom of all
units and feature 3/4" glands.
Liquid-cooled SINAMICS S120 units in Chassis format:
Example of a Basic Line Module, an Active Line Module and a Motor Module, and power losses which are dissipated
directly to the coolant. Please refer to catalog D 21.3 for the individual, unit-specific values.
Liquid-cooled SINAMICS S120 units in Chassis format with low output ratings (AC/AC Power Modules in frame
sizes FL and GL, Active Line Modules in frame size GXL, and Motor Modules in frame sizes FXL and GXL) feature a
heat sink with integrated stainless-steel heat exchanger. The requirements of these units with respect to cooling
circuit and coolant properties tend to be low which means that they can be cooled by either a closed or an open
cooling circuit.
Liquid-cooled SINAMICS S120 units in Chassis format with high output ratings (Basic Line Modules in frame
sizes FBL and GBL, Active Line Modules in frame sizes HXL and JXL, Active Interface Modules in frame size JIL and
Motor Modules in frame sizes HXL and JXL) have an aluminum heat sink through which the coolant flows directly.
This design ensures the most effective heat transfer possible between the heat sink and the coolant. However, the
aluminum construction tends to place high demands on the cooling circuit and the coolant properties which means
that units of this kind must be cooled by a closed cooling circuit.
SINAMICS Engineering Manual – November 2015
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Ó Siemens AG
Power losses dissipated directly to the coolant
referred to the total power losses of the unit in %
(refer to catalog 21.3 for individual, unit-specific information)
Liquid-cooled
SINAMICS S120 unit
AC / AC unit
Basic Line Module (BLM)
Active Line Module (ALM)
Motor Module (MoMo)
Voltage range
380 V – 480 V 3AC
510 V – 720 V DC
≈ 97,5 %
≈ 91,5 % FBL: ≈ 86 % / GBL: ≈ 91 %
≈ 94,5 % - 96,5 %
≈ 94,5 % - 96,5 %
Voltage range
500 V – 690 V 3AC
675 V – 1035 V DC
≈ 97,0 %
≈ 95,0 % - 97,0 %
≈ 95,0 % - 97,0 %