The Siemens 3SE5112-0LD02 is a SIRIUS mechanical position switch in a metal block-narrow housing with a roller plunger actuator — a standard EN 50041 design C head. It's built for positive-opening snap-action contacts, meaning the normally-closed circuit physically breaks open even if the contacts weld, which is what earns it a place in safety circuits guarding access points on conveyor zones, machine enclosures, or palletizers. Rated IP66/IP67, the metal housing with cathodic dip coating handles washdown environments and outdoor installation without corrosion issues — common on sorting lines or packaging machines where hoses are the cleaning tool.
Thermal current Ith is 10 A, but the real switching limits depend on voltage and load type: at 240 V AC it's rated 6 A, at 24 V DC it's 3 A, and at 400 V AC it drops to 0.12 A. That 400 V figure is the insulation voltage rating — the switch is designed for 400 V systems, but the contact rating at that voltage is low, so it's a signal-level or low-power interlock at line voltage, not a motor-load switch. Repeat accuracy of 0.05 mm means the switch trips at nearly the same actuator position every cycle — important for precision cam tracks or registration-based diverters where consistent timing avoids product jams. Shock resistance per IEC 60068-2-27 is 30 g for 11 ms — that covers most conveyor impact and vibration without false trips.
Wiring and mounting details
Screw-type terminals accept 1x (0.5 to 1.5 mm²) solid or 2x (0.5 to 0.75 mm²) solid; AWG equivalents are 1x (20 to 16) solid and 2x (20 to 18) stranded. Single M20 x 1.5 cable entry — plan your conduit or gland accordingly. Mounting position is any orientation; fastening is by screw fixing through the 40 mm wide, 116.3 mm long metal body. The roller plunger uses a high-grade steel roller, so it holds up against steel cams or hardened actuator dogs without galling.
For BOM compliance, the switch carries a substance prohibitance date of 07/01/2006, aligning with RoHS and REACH substance restrictions. No UL or CSA listing appears in the spec record, so verify with your local Siemens rep if a specific agency mark is required for your panel certification.