Cooling Circuit Configuring Information - Siemens Sinamics S120 Manual

9.1.4

Cooling circuit configuring information

The operating pressure must be set according to the flow conditions in the supply and return
lines of the cooling circuit. The required coolant flow rate per time unit must be set according
to the technical data of the relevant devices. The devices are normalized to a rated pressure
of 70 kPa (for coolant type H
If a mixture of antifreeze and H
calculated according to the mixing ratio.
The maximum permissible pressure to atmosphere in the heat sink and thus in the cooling
circuit must not exceed 6 bar. If the pump used can reach a maximum pressure in excess of
this value, appropriate measures (safety valve p ≤ 6 bar, pressure control or similar) must be
implemented by the customer to ensure that the maximum pressure limit is not exceeded.
The lowest possible differential pressure between the coolant in the supply and return lines
should be selected to allow use of pumps with a flat characteristic.
The maximum differential pressure across a heat sink is 200 kPa; higher differential
pressures significantly increase the risk of cavitation and abrasion.
Figure 9-4 Pressure drop as a function of volumetric flow
Liquid-cooled chassis power units
Manual, (GH7), 11/2016, 6SL3097-4AM00-0BP7
Cooling circuit, coolant properties and protection against condensation
O) via an orifice.
2
O is used as a coolant, the rated pressure must be
2
9.1 Cooling circuits
317