Most pumps in the aquaristic branche are sensible against running-dry - especially high-value energy saving pumps should be protected against running-dry. If a circulation pump sucks air damages may occur.
The level switch of the BasiTechTM unit is mounted at minimum water level, for example in the filter tank. The circulation pump that pumps the water out of this tank is connected with the BasiTechTM unit. After putting the unit into operation and the water level in the tank is over the minimum level the pump will start (green and yellow LEDs are flushing). If the water level falls below the lower level switch position the pump is shut-off by the BasiTechTM unit. A restart is only possible if the control is dissconnected from the mains for some seconds.
Tip! Check the function of the unit regularly. Especially the float of the level switch has to be checked if it is jammed.