Cooling System Requirements - Siemens Sinamics S120 Manual

Cooling circuit and coolant properties
13.1 Cooling circuit requirements
13.1.2

Cooling system requirements

Open cooling systems must never be used for liquid-cooled power units. A closed cooling
circuit with a membrane expansion tank, safety valve, and heat exchanger is recommended,
which connects the cooling circuit to an external cooler (refer also to Chapter Using heat
exchangers (Page 808)).
Requirements
● A particle filter (particle size < 100 µm) must be installed in the cooling circuit to prevent
foreign particles from being washed in.
● Mixed installations should be avoided wherever possible.
● The permissible pressures in the cooling system must be observed.
● Cavitation must be prevented in the cooling system.
● Equipotential bonding must be provided between the components in the cooling system.
● The customer must take measures to protect the devices against condensation.
● An anti-corrosion agent and, if necessary, a biocide should be mixed into the coolant.
● If there is a risk of frost, preventive measures must be taken during operation, storage,
and transportation (e.g. emptying and blowing out with air, additional heating).
● The requirements of the coolant in terms of its properties (temperature, chemical
characteristics, etc.) must be observed.
Recommendations
● To ensure mechanical decoupling, the devices should be connected by means of hoses.
● To prevent blockages and corrosion, you are advised to install a flushback filter in the
circuit (so that residues can be rinsed out when the system is running).
● The power units should be connected to the cooling circuit by means of shut-off fittings so
that they can be disconnected from the cooling circuit for servicing or repair without
having to empty the entire cooling system. A cooling water hose (EPDM) can be used to
connect the shut-off fitting to the power unit. The coolant connections must never be
closed if cooling liquid is still present in the device. Reason: If the cooling fluid expands
due to heat, the pressure can build up beyond permissible levels and cause the heat sink
to burst.
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Booksize Power Units
Manual, (GH2), 04/2014, 6SL3097-4AC00-0BP6