Generic P31 Small Float Level Control Switch Plastic Float Switch - NC Type

NO (Normally Open) means the switch contacts are open when the float is in its resting position and close when activated. NC (Normally Closed) means the contacts are closed at rest and open when activated. The P31 is a Normally Closed (NC) type float switch. This design is often used for fail-safe applications, such as turning off a pump when a tank is full, as the circuit will open and stop power if the float rises.

The P31 float switch is rated for a maximum switching voltage of 220V AC or DC and a maximum switching current of 0.5 Amps. It can carry a continuous current of up to 1 Amp. It is crucial not to exceed these ratings to prevent switch failure, arcing, or safety hazards. For higher loads, always use the switch to control a relay or contactor.

The switch housing and float are constructed from Polypropylene (PP), which is resistant to many water-based solutions, mild chemicals, and oils. It is not suitable for strong acids, solvents, or fuels that may degrade PP. The operational temperature range is from -10°C to 60°C, defining the environmental conditions for both the liquid and the surrounding air.

Installation is straightforward. Mount the switch vertically in the tank using its threaded boss or a suitable bracket, ensuring the float can move freely. Connect the two wires from the integrated 35cm cable in series with your load (e.g., pump, alarm, relay coil) and power source. Since it's an NC switch, the circuit is complete when the float is down. The circuit will open and interrupt power when the liquid level rises and lifts the float.