Thermal Operation Characteristics

The actuator can be continuously operated within the rated operation limits. The figure shows the rated operation limit as blue shaded area. Up to these limits, the actuator temperature will reside below the maximum admissible temperature t_max (red dashed line).

The actuator can be intermittently overloaded up to the peak operation limits indicated by the red shaded area. During this intermittent operation, the actuator temperature will rise towards the maximum admissible temperature and eventually exceed it. For a given generated torque, the blue graph in \fig{fig:thermalChar} illustrates the time it takes the motor to heat up from ambient temperature (25 °C) to t_max. If the actuator heats up beyond this temperature, thermal wear to the windings must be expected.

Note that the characteristics displayed in the figure above must not be considered sharp boundaries. They are theoretical values considering the thermal resistances and time constants in the parameter table. Those parameters are obtained from a standardized experiment where the actuator without active cooling is mounted in free air against a plastic flange. The true thermal characteristics for a given application depends on many other parameters, such as the actuator operation history (actual winding temperature), true ambient temperature, humidity, the actual mounting and potential cooling of the motor.