The relay is delivered in 2 variants - depending on how the voltage levels are set and monitored.

HRN-41 has a "hysteresis" function, i.e. only the upper level (Umax) is set and the lower level (Umin) is set in % of the upper level. Therefore, the lower level changes automatically as soon as the upper level changes.

HRN-42 has a "window" function, i.e. the upper level (Umax) and the lower level (Umin) are set individually in % of the monitored voltage. Both types have a "MEMORY" function. If the relay enters the fault state, the setting is stored until the reset button is pressed. DIP switch no. 3 is used to set whether the relays should switch independently for each level or in parallel if the voltage level is exceeded or not reached. DIP switch no. 4 is used for hysteresis setting, which takes effect when resetting from fault state to normal state. The relay is protected against reverse polarity of the DC voltage or wrong AC/DC input voltage. This is indicated by simultaneous blinking of both LEDs (LED <U and LED >U).