A float switch is a device used to sense the level of liquid within a tank. The switch may actuate a pump, an indicator, an alarm, or other device. It can be easily converted from normally open to normally close by invertin the float. Black line is common,The red line is to control the upper ball valve (threaded down);The yellow line is to control the lower ball valve (threaded down) Note: because the current that the switch can carry is much little(0.5A), you must use a relay or contactor when it is connected by a load, relay and contactor are not included here.
