Ziehl Control relay Level relay NS 20

Use with 3 electrodes as a Min/Max control for filling or emptying a container, with 2 electrodes for overflow or dry run protection. The AC measurement path is completely free of direct current. This prevents electrolytic decomposition of the electrodes and the formation of explosive gas. Isolated conductors can be used as electrodes. In conductive containers, the container wall serves as the base electrode.