Siemens Industry, Inc. 3SE03-AT1 Limit Switch

Siemens 3SE03-AT1 limit switch is a plug‑in, metal‑bodied industrial switch from the 3SE03 family with a plain top plunger actuator and momentary action. It offers a single‑pole, 1NO+1NC contact configuration with about 5° pretravel to ensure reliable switching in tight tolerances. The AT1 variant uses a die‑cast zinc housing with epoxy coating and is rated for broad enclosure levels (NEMA 1/3/3S/4/4X/6/6P/11/12/13; IP66) and a 1/2‑inch NPT threaded opening for cable or conduit entries, supporting up to 1,000,000 mechanical cycles. Typical applications include machine safety interlocks, end‑of‑travel sensing on conveyors, and general control circuits in manufacturing where a compact, plug‑in limit switch is advantageous.