Electrode level relay ST/NR

July 2011

Conductive level relay


The electrode level relay ST/NR can be operated with single-pole electrodes when using an earth electrode or with two-pole electrodes.
If the level of the liquid reaches the upper electrode a start command is issued to the pump. As soon as the liquid level drops below the electrode a stop command is issued to the pump.
Alternating voltage is utilised to prevent electrolytic degradation.
That limits the length of cable between the electrode and the device.
The response sensitivity can be set via the integrated potentiometer.
LEDs indicate the actual control state of the relay.


    The relay is mainly used in applications in which containers are automatically filled and drained. In addition, it is also utilised as protection against containers overfilling or running dry.