Float switch

What is a Float Switch Cable?

A float switch cable, or cable-type float switch, is designed to measure and control liquid levels in tanks or wells. It provides level warnings through relays or sends signals that function as switches to connect with PLC systems for operational control. Suitable for various applications such as chemicals and high-temperature liquids, expert engineering teams are available for consultation and custom production according to customer needs.

Structure and Operation of Float Switch Cable

Structure of Float Switch Cable

The exterior of a float switch cable is typically seen as a plastic buoy made from Polypropylene (PP) connected to wires. The crucial mechanism inside the buoy includes:

• Metal Ball: Moves along with gravity.
• Microswitch: Receives pressure from the metal ball.

Operation of Float Switch Cable

When water levels change, the buoy floats up or down, causing the internal metal ball to press against or release from the switch stem. This automatically closes or opens the electrical circuit.

Lever Arm Control for Level Adjustment (Counterweight)

The unique feature of this type of switch is a counterweight attached to the cable that acts as a pivot point, determining the depth at which the switch operates:

Short distance: The pump cycles more frequently (small water level changes).

Long distance: The pump runs longer (larger water level changes).

Wiring Functions of Float Switch Cable

A float switch cable typically comes with 3 wires (Common, NO, NC) to choose from two main functions:

Emptying/Drainage Function:

• NO (Normally Open): When the tank is full (buoy floats up), the switch activates the pump to drain water (preventing overflow).

Filling Function:

• NC (Normally Closed): When the tank is empty (buoy sinks down), the switch activates the pump to fill water (preventing dry run or low level).

View our Float Switch Cable Catalog here