In case of abnormal heating or overtemperature warnings and faults, the following should be checked first and foremost:
- Cooling pumps are running. The inverters should be cooled even when switched off if they are connected to a DC link. The permanent magnet machines generate a power loss when in rotation, even when the machine is unloaded, and thus must always be cooled when the shaft is rotating.
- Cooling flow is sufficient. The required flow rates, pressures, and temperatures must be as stated in the data sheets of each device and machine model. The cooling circuit should be inspected for possible air bubbles.
- Connections are alright. The cooling circuit connections should be checked for any leaks.