Positive opening for safety circuits
The 3SE5122-0CH01 uses snap-action contacts with a positive opening mechanism, meaning the NC contacts are mechanically forced open when the actuator is operated — this is the feature that qualifies it for use in safety circuits where a welded contact must not go undetected. The roller lever actuator (metal lever, 27 mm long, 9 mm step, plastic roller 19 mm) follows EN 50041 design A, so it mates with standard actuator heads on guards and gates.
Sealed for washdown, repeatable for positioning
IP66/IP67 protection class means the metal enclosure (cathodic dip coated) keeps washdown water and dust out — suitable for food processing, packaging, or outdoor conveyor lines where a hose-down is part of the shift cycle. The 0.05 mm repeat accuracy gives you a consistent trip point for position sensing, so a gate or diverter that cycles thousands of times a day doesn't drift.
Wiring and mounting constraints
Screw terminals accept 1x (0.5... 1.5 mm²) solid or 2x (0.5... 0.75 mm²) solid, with AWG equivalents 1x (20...16) solid and 1x (20...16) stranded. Three M20 x 1.5 cable entries give you room for separate power and signal runs — one entry for the incoming supply, one for the safety circuit, one spare for a future add-on. Mounting position is any orientation, screw fixing, block-wide housing (56 mm wide, 127.5 mm long). The supplied basic switch is 3SE5122-0CA00 and the operating lever is 3SE5000-0AA01 — if the lever gets damaged in service, you order the lever separately without replacing the whole switch.
Current ratings across voltage bands
Thermal current (Ith) is 10 A, but the switching current depends on the voltage and load type: at 240 V AC it switches 6 A, at 24 V DC it switches 3 A, at 125 V AC 0.55 A, at 250 V DC 0.27 A, at 400 V DC 0.12 A. The 400 V insulation voltage rating covers most 3-phase control circuits up to that line-to-line level.