Tutorial about float switches by MAC3. A quick, step-by-step tutorial on installing the MAC3 float switch for submersible and electric the float reaches a certain position, it activates or deactivates an electrical contact, thus allowing the water pump to start or stop based on the liquid level. 0:00 Mac3 Float Switches 0:17 Counterweight assembly 0:33 Electrical wiring 0:59 How it works MAC3 float switches (such as the Key, Small, or Mac5 models) are renowned for their reliability in level control across a wide range of liquids: from clear and drinking water to wastewater, greywater, and turbulent liquids with suspended solids.