Siemens 3SE03-AT3 Limit Switch Push Roller Spring Return

Siemens 3SE03-AT3 is a limit switch with a roller-top plunger and spring-return action, configured as 1 NO and 1 NC contact. The AT3 variant specifies a roller top actuator and momentary (spring-return) operation, designed for end-of-travel and position sensing in industrial equipment. Actuation is provided by a roller plunger that engages when a moving part reaches a stop and then returns to the home position automatically. As part of the 3SE03 family, the AT3 is compatible with Siemens plug-in module/receptacle systems (EN50041-based), enabling straightforward field replacement and integration in control panels. This configuration—roller top plunger, momentary action, 1NO + 1NC contacts—offers a compact, reliable solution for mechanical limit sensing in conveyors, presses, and machinery where precise travel detection is required.