Float level switch AT 120 HR HY

submergedfor corrosive liquidsfor wastewater

Overview
The AT 120 HR HY is a float level switch for automatic level control in aggressive or agitated liquids. Its HR HY press‑vulcanised biconical housing provides double waterproofing and chemical resistance suitable for industrial and wastewater applications.

Operating principle
The unit operates by the free pivoting of the float as liquid level rises and falls. At a preset angle the float actuates an internal mechanical switch (selectable NO/NC) via the three‑core cable (COM, NO, NC). When used in pairs, it enables reliable minimum/maximum level regulation of tanks and sumps.

Modes

• Drain mode: closes the circuit at high level to start the pump (overfill protection); opens when the tank is emptied to stop the pump.
• Fill mode: closes the circuit at low level to start the pump for refilling.

Notes
Not recommended for very slow filling applications; for such cases prefer the SOBA HR HY level regulator. For installations in explosive atmospheres, select the ATEX certified SOBA EX model. Designed and manufactured in France.

Technical specifications

• Switching angle: +/- 120°
• Allowed fluid density: 0.70 to 1.15 kg/dm³
• Maximum operating pressure: 4 bar
• Maximum temperature: 90 °C
• Ingress protection: IP68
• Housing: HR HY press‑vulcanised biconical body (HR HY + copolymer polypropylene components)
• Cable: 3 x 1 mm² HR HY
• Weight (float without cable): 295 g
• Ballast: 175–250 g (filled resin)
• Standard cable lengths: 3 m, 5 m, 6 m, 10 m, 13 m, 15 m, 20 m, 25 m, 30 m
• Electrical examples: 250 V AC resistive 20 A; 250 V AC inductive 8 A; 250 V DC resistive 1 A; 48 V DC 1.5 A