Information About The Cooling Circuit And The Cooling Circuit Configuration; Design Of The Liquid-Cooled Cabinet Modules; Required Converter-Side Deionized Water Circuit - Siemens SINAMICS G130 Engineering Manual

7.3.4 Information about the cooling circuit and the cooling circuit configuration

7.3.4.1

Design of the liquid-cooled Cabinet Modules

General information
The liquid-cooled SINAMICS S120 Cabinet Modules are based on the liquid-cooled SINAMICS S120 built-in units in
Chassis format. For this reason, the information in section "Liquid-cooled SINAMICS S120 units" of chapter
"Fundamental Principles and System Description" relating to liquid-cooled Chassis units is also valid for SINAMICS
S120 Cabinet Modules. This applies in particular to the cooling circuit and the coolant requirements. S120 Cabinet
Modules in degree of protection IP55 are subject to some minor restrictions with respect to maximum permissible
coolant temperatures.
The built-in units in Chassis format (Basic Line Modules in frame sizes FBL and GBL, Active Line Modules in frame
sizes HXL and JXL, and Motor Modules in frame sizes HXL and JXL) installed in liquid-cooled SINAMICS S120
Cabinet Modules 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 tends to place high
demands on the cooling circuit.
For this reason, it is essential that liquid-cooled SINAMICS S120 Cabinet Modules are operated with a closed cooling
circuit. This closed cooling circuit is made possible by the use of a Heat Exchanger Module which supplies the
converter-side closed deionized water circuit and separates it from the plant-side raw water circuit. The converter-
side closed deionized water circuit must be filled with a coolant that meets the requirements for aluminum heat sinks
(see section below).
7.3.4.2

Required converter-side deionized water circuit

In order to prevent corrosive, electro-chemical processes in the converter-side closed deionized water circuit, or at
least inhibit them to an absolute minimum and so ensure problem-free operation of the cooling circuit for many years,
the following materials are used:
- The piping in the Cabinet Modules is made of corrosion-resistant plastic (PP-R)
- The components in the Cabinet Modules are connected by means of insulating EPDM hoses
- The pump in the Heat Exchanger Module is made of corrosion-resistant stainless steel
- The heat exchanger in the Heat Exchanger Module is made of corrosion-resistant stainless steel
The coolant required for the converter-side, closed deionized water circuit is a mixture of water and anti-freeze. The
water must meet the quality requirements specified below for devices with aluminum heat sink.
Coolant specification for SINAMICS S120 Cabinet Modules with aluminum heat sink
Deionized water with the following properties as defined by ISO 3696 / grade 3, combined with an anti-freeze
according to the specifications on the following page:
·
pH value at 25°C
·
Electrical conductivity at 25°C
·
Components that can be oxidized as oxygen content
·
Residue after vaporization and drying at 110 °C
Anti-freezes prevent the coolant from freezing at temperatures below zero and contain inhibitors and biocides to
ensure a continuous and stable chemical balance in closed cooling circuits. The agents specified in the table must be
used as anti-freeze for the converter-side deionized water circuit in liquid-cooled SINAMICS S120 Cabinet Modules.
Used in very low concentrations, anti-freeze has a corrosive effect. Very high concentrations of anti-freeze prevent
effective heat dissipation. For these reasons, it is vital to observe the minimum and maximum concentrations
specified in the table. It must also be noted that the addition of anti-freezes increases the kinematic viscosity of the
coolant, making corresponding adjustment of the pressure conditions necessary.
SINAMICS S120 Cabinet Modules
Engineering Information
SINAMICS Engineering Manual – November 2015
5.0 to 7.5
< 5 mS/cm
< 0.4 mg/l
< 2 mg/kg
455/528
Ó Siemens AG