The standstill monitor detects standstill of a motor after shutdown and then permits access to the danger areas. No additional sensors are required: the standstill monitor measures the induced voltage of the decelerating motor at the terminals of the stator winding. If this voltage approaches zero, the device detects motor standstill and actuates, for example, the protective door interlock. The voltage threshold Uan and a downstream delay timer can be set by the user according to requirement.

Two safety functions in one unit

The speed monitor performs continuous standstill and speed monitoring functions in machines and plants. Simple parameterization and constant diagnosis via the display enable faults to be rectified quickly every time - often before they lead to a plant standstill.