Selecting An External Heat Sink - Bosch rexroth EFC 610 Series Operating Instructions Manual

Rexroth Frequency Converter EFC x610
Series

7.5.5 Selecting an External Heat Sink

The heat transfer principle from the cold plate to the heat sink ambient air is
shown as below:
Fig. 7-15: Thermal equivalent circuit
Temperature around the cold plate must be not more than 45 °C.
●
Temperature of the cold plate must be not more than 70 °C.
●
The formula to calculate the maximum thermal resistance of the heat sink is as
follows:
Fig. 7-16: Calculation formula of thermal resistance
CP : Cold plate loss [W]
Loss
T : Maximum cold plate temperature [°C]
CPmax
R : Equivalent thermal resistance of cold plate [°C/W]
CP
R : Thermal resistance of external heat sink [°C/W]
HSmax
T : External heat sink ambient temperature [°C]
AMB
R : Thermal resistance between cold plate and external heat sink [°C/W]
COMP
The thermal resistance between the cold plate and the external heat sink can be
calculated by:
Frequency Converter Mounting
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