Electromechanical level switch SOBA S

floatfor waterfor pump control

Presentation
The SOBA S (SPEED) is a vertical-acting level controller designed for confined spaces where conventional tilt floats cannot operate. Intended for automatic pump control in clear water and wastewater applications, it allows flexible installation so that minimum and maximum trigger levels are defined by the float position.

Benefits and applications
The SOBA S operates reliably in media containing solids or deposits that can block magnetic controllers. It detects liquid level with only 10 cm immersion. Typical uses include high/low level alarm, overflow protection and dry-run protection. A high-resistance version (SOBA S HR HY) is available for aggressive liquids. Designed and manufactured in France.

Operating principle
The regulator moves with the liquid level. When the float reaches the set point it tips and the mechanical switch opens or closes depending on the selected mode. The unit is supplied with a 3-conductor cable (COM, NO, NC) for use in drain or fill modes.

Operating modes

• Drain mode: the level switch controls pump start/stop to prevent overflow and cuts power when the tank is empty (dry-run protection).
• Fill mode: the circuit closes in the low position (NC) to start the pump and fill the tank.

Adjustment and installation
The position of the weight on the cable adjusts the switching angle and the difference between trigger levels. Increasing the distance between the weight and the float increases the level differential and switching angle. The weight (clip or resin) unclips and repositions easily to set the trigger height. Electrical connections must be sealed and isolated in a hermetic box outside the tank. The cable and capillary can be extended; ATMI supplies adapted cable lengths.

Technical features / specifications

• Operating angle: +/- 110°
• Admissible fluid densities: 0.70 to 1.15 kg/dm³
• Maximum service pressure: 3.5 bar
• Maximum service temperature: 85 °C
• Ingress protection: IP 68
• Biconical housing: copolymer polypropylene
• Cable (3 conductors 1 mm²): neoprene (standard), HR HY (high-resistance available)
• Float weight without cable: 105 g
• Weight (ballast): 175 - 250 g resin loaded
• Standard cable lengths: 3 m, 5 m, 6 m, 10 m, 20 m
• Minimum detection immersion: 10 cm
• Electrical characteristics (indicative, depend on load): typical ratings on datasheet: VAC 250 V resistive 20 A; VAC 250 V inductive 8 A; other common voltages: 48 V, 24 V with currents adapted to load (see datasheet for detailed correspondences).