Cable Length: The defining feature is the 5-meter (approx. 16.4 feet) long cable. This provides significant flexibility in installation depth and placement.
Switch Type: Most common models use a reed switch activated by a magnet inside the float, or a mercury switch (less common now due to environmental concerns). Reed switches are reliable and sealed from the liquid.
Operation Type:
Normally Open (NO): The circuit is open (off) when the float is down and closes (on) when the float is up.
Normally Closed (NC): The circuit is closed (on) when the float is down and opens (off) when the float is up.
Some models offer a combination of both NO and NC contacts within a single switch.
Electrical Rating: The maximum voltage and current the switch can handle (e.g., 250VAC, 10A). It is critical to match this with the pump or load it controls. Never exceed the switch's electrical rating.
Material: The float and cable are typically made from materials resistant to corrosion and chemicals, such as:
Float: Polypropylene (PP), Nylon, or PVC for water, sewage, and mild chemicals.
Cable: PVC jacketing, often with a stainless steel weight on the cable to keep it hanging straight and prevent tangling.
Temperature and Chemical Resistance: The specific material grade determines the liquids it can handle and the operating temperature range (e.g., 0°C to 80°C is common)