›› OPTIMUM COOLING BY AIR OR LIQUID
Resistors are designed to convert electrical energy into heat, which is why heating of the exhaust air and adjacent housing parts is unavoidable. Temperature management is therefore of particular importance for braking resistors. Indeed, in many cases, the products are used in the most confined environments. Products of different types or several braking resistors inevitably influence each other in this case. A first step is therefore to check the substrate on which the braking resistor has been installed regarding its heat-conducting properties. Poor thermal conductivity leads to a higher operating temperature of the resistor. This can be remedied by mounting the resistor directly on a heat sink or cooling surface, which significantly increases the continuous power of the resistor, or reduces the surface temperature. Depending on the type and size of the cooling surface or heat sink, the power can be increased by a factor of 1.5 up to 4. For the highest possible safety there is the possibility to monitor the temperature of the resistor with a temperature switch. When a nominal temperature is exceeded, the temperature switch opens and triggers a signal contact. For this purpose, the temperature switch is provided with two stranded wires ready for connection.
If the installation conditions are not optimal due to the compact construction or due to protective devices against environmental influences, so that a supply and exhaust air can not be achieved as well as a sufficient heat dissipation via cooling surfaces, liquid cooled systems from REO can be used.