SIRIUS 3RH1344-1DB40-0KA0 — Auxiliary Contactor, 24 V DC, 4 NO
The Siemens 3RH1344-1DB40-0KA0 is a SIRIUS auxiliary contactor in size S00, designed for switching control and signal circuits in industrial panels. Its 24 V DC coil draws 3.2 W for both closing and holding, with an integrated varistor surge suppressor across the coil terminals — no external suppression diode needed for DC switching, which simplifies panel wiring and BOM count. The contact block provides four normally open (NO) instantaneous contacts rated for operational currents that vary with voltage: 10 A at 24 V, 6 A at 230 V, 3 A at 400 V, and 1 A at 690 V. Mechanical endurance is rated at 10 million operating cycles, with contact reliability specified as one incorrect switching operation per 100 million operations at 17 V, 1 mA.
Mounting and Integration
Mounting is via screw fixing or snap-on onto a 35 mm DIN rail per the fastening method. The 45 mm width (3 SBE — 3 standard width units) fits standard S00 contactor spacing. Mounting position allows ±180° rotation on a vertical surface and ±22.5° tilt forward/backward, giving flexibility in tight enclosures. The IP20 protection on the front suits enclosed panel installation — not for washdown or outdoor use without an additional enclosure.
Terminal Wiring and Environmental Limits
Solid conductor cross-sections accepted: 2x 0.5…1.5 mm², 2x 0.75…2.5 mm², and 2x 4 mm². Pollution degree 3 (conductive pollution or dry non-conductive pollution that becomes conductive due to condensation) means the contactor is rated for industrial environments where occasional condensation or conductive dust is expected. Operating temperature range is -25 to +60 °C; storage and transport range is -55 to +80 °C. Shock resistance is 10g / 5 ms and 5g / 10 ms.