Thermal Mounting Considerations

SOMANET Circulo is designed to be integrated into a robot or machine.

To reach the specifications of SOMANET Circulo, thermal aspects have to be considered during this integration. The following instructions shall be followed:

  1. The air surrounding the SOMANET Circulo must be no hotter than 60 °C. This typically refers to the air inside the robot housing or inside the machine.

  2. SOMANET Circulo must be mounted to a mounting structure that is no hotter than 70 °C (“mounting temperature”). This mounting structure:

    1. must be made of metal, preferably aluminum

    2. have a surface quality of Rz16 or better

    3. can be the robot or machine structure, the motor housing or other parts.

  3. Mounting of Circulo must be done using all mounting screws. The entire thermal interface surface (highlighted in the drawing below) must touch the mounting structure. In operating cases that are very close to the thermal limits, we recommend using a very thin layer of electrically conductive thermal paste.



This interface is also used for connecting Functional Earth. For details, please refer to our application note on earthing.

Current as a function of mounting temperature

Operation with mounting temperature cooler than specified above can increase the technically possible maximum continuous current and related performance specifications, as shown in the figure below.

Operation with mounting temperature hotter than specified is possible in a limited extent. However, the maximum continuous current and related performance specifications derate heavily in that case - see figure below.

Circulo 7Circulo 9Circulo 7
Circulo 9

* Extended continuous operating range. Values have been reached in tests but can not be ensured. Use at own risk.

** Please refer to the load cycle


Using this extended temperature/current range is at your own risk. All tests, qualifications and certifications are done up to nominal mounting temperature only. Your own extensive testing and qualification inside your specific application is mandatory in this context.

Ambient air

Operation in ambient air temperature cooler than specified above is no appropriate measure to increase the specifications of the device, neither in power nor in current. Operation in ambient air temperature hotter than specified above is not allowed.


If Circulo is mounted directly to a motor, it must be considered that motors can reach significantly higher temperatures if continuously being operated at their max. continuous current. In such a case, the full continuous torque spec of the motor cannot be used continuously. This must be considered during design - in doubt, a motor model with higher max. continuous torque should be used to keep the motor temperature lower, thus maintain the mounting temperature requirements.