The Siemens 3RT1344-1AH20 is a SIRIUS S3 power contactor — a screw-terminal, three-pole unit rated for switching motor loads up to 42 kW at 230 V (AC-3 duty at 60 °C) and carrying a 1000 V insulation voltage rating. Pollution degree 3 (conductive pollution, typical for control enclosures without climate control) is baked into the design. The size S3 frame (146 x 93 x 139 mm) fits standard panel layouts with side-by-side mounting permitted, so you can pack multiple contactors without derating for heat buildup. Front face carries IP20 protection — safe for finger contact in a closed cabinet. The terminal area is IP00, meaning the main circuit lugs are exposed once the cover is off; standard panel practice applies.
RoHS compliance date is 05/01/2012.
Termination & Wiring
Solid wire capacity: 2x (0.5...1.5 mm²), 2x (0.75...2.5 mm²), max 2x (0.75...4 mm²). Stranded: 2x (10...50 mm²). Minimum permissible cross-section at 40 °C and 60 °C is 35 mm² — that's the thermal limit for continuous current; the contactor can accept smaller wire for control circuits, but the main circuit should not be undersized below that.
Coil & Switching Characteristics
Rated control supply voltage: 48 V at 50/60 Hz. Operating range: 0.8...1.1 x Us at 50 Hz, 0.85...1.1 at 60 Hz. Drop-out and arcing times: 10...25 ms AC (10...15 ms arcing). Switching frequency at AC-1: up to 1000 operations per hour. Rated breaking capacity at 24 V: 10 A; at 60 V: 2 A; at 110 V: 1 A; at 220 V: 0.3 A; at 230 V: 6 A; at 400 V: 3 A. These are DC switching values — important when using the contactor for DC loads or in DC-intermediate circuits.
Environmental & Mechanical
Operating temperature: -25 to +60 °C. Storage: -55 to +80 °C. Mechanical service life: 10 million operations typical. The wide storage range covers most transport and warehouse conditions.