Cooling Circuit And Coolant Properties; Cooling Circuits - Siemens SINAMICS S120 Equipment Manual

Cooling circuit and coolant properties

Warning
The equipment must be safely disconnected from the supply before any installation or
service work is carried out on cooling circuit components.
The cooling circuit must always be designed and installed by an appropriately trained
engineer.
Note
The contact addresses for companies named in this section are available on request for your
local Siemens sales office.
8.1

Cooling circuits

General information
The type of heatsink materials used requires two distinctly different recooling concepts.
Different materials are used to guide the coolant into the cooling plates of the SINAMICS
S120 Liquid Cooled units, providing the user with a range of different options for the design
of the cooling circuit.
The electrochemical processes that take place in a cooling system must be minimized by
choosing the right materials. For this reason, mixed installations (i.e. a combination of
different materials, such as copper, brass, iron, or halogenated plastic (PVC hoses and
seals)) should not be used or limited to the absolutely essential minimum.
Please read the following definitions for clarification:
1. Closed cooling circuit
The pressure compensator is closed (no ingress of oxygen) and is fitted with a pressure-
relief valve (6 bar); it is always connected on the suction side of the pump! The coolant is
guided only through the SINAMICS units, the recooling components and possibly to a
motor (for example, see Fig. 8-1). The materials used in the cooling circuit comply with
the recommendations in Section 8.3.
2. Open cooling circuit
The coolant is guided through the SINAMICS units and the recooling components, as well
as through components external to the cooling circuit. The materials used comply with the
minimum requirements stipulated in Section 8.3.
3. Semi-open cooling circuit
Oxygen can be transferred to the coolant only via the pressure compensator, otherwise
as for 1.
Chassis Power Units Liquid Cooled
SINAMICS S120 Equipment Manual, Edition 12/2007, 6SL3097-2AM00-0BP4
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8-1