- Overtemperature (heat sink) due to overload of device
- Ambient temperature too high. Specified performance data is valid up to an ambient temperature of 40 °C
- Heat sink of device is dirty
- Convection is prevented by other components or mounting position in control cabinet
- Device-internal blower failed
- Failure of air conditioning for control cabinet
- Incorrect dimensioning of control cabinet with regard to heat dissipation
- For liquid-cooled devices: No cooling system connected
- For liquid-cooled devices: Error in cooling system, e.g. coolant pump defective or filter clogged; thereby flow rate too small / inlet temperature of coolant too high