Integrator's first read
The Siemens SIRUS 3RT2535-3XF40-0LA2 is a power contactor in the S2 frame size, designed for switching motor loads and resistive circuits in industrial control panels. Its DC coil is rated at 110 V, with a spring-type terminal connection for the magnet coil — no screw torque to verify on that circuit, just strip and insert. Mounting is via screw or snap-on onto 35 mm DIN rail per DIN EN 50022, so it drops into a standard panel rail without extra brackets. The mounting position is flexible: ±180° rotation on a vertical surface, and can be tilted forward/backward by ±22.5° on vertical surfaces. Operating temperature range is -40 to +70 °C during operation, with storage from -55 to +80 °C — suitable for unheated enclosures in temperate climates.
DC switching capacity — what the ratings mean
The contactor's DC switching capacity is specified per voltage level, not as a single maximum current. At 24 V it handles 10 A; at 48 V and 60 V, 2 A; at 110 V, 1 A; at 220 V, 0.3 A; at 400 V, 3 A; at 600 V, 0.1 A. These are the make/break ratings for DC loads — resistive or slightly inductive — and they drop sharply above 24 V because DC arcs sustain longer than AC. For AC-4 duty (switching motor loads with inrush), the maximum switching frequency is 300 operations per hour. The arcing time is 10 to 20 ms, and the DC operating time (coil energization to contact closure) is 30 to 55 ms. Main contacts are configured as 3 normally open (3 NO) for the power circuit, plus one auxiliary switch (1 NO/1 NC) for feedback or interlocking. The inrush current peak for the coil is 1.5 A.
Panel layout and wiring
Dimensions: 75 mm wide, 114 mm high, 130 mm deep. Clearance distances: 10 mm upwards, 10 mm forwards, 10 mm downwards, 6 mm at the side. These are the minimum free air gaps around the contactor for arc flash and heat dissipation — factor them into your DIN-rail layout. Terminals accept solid or stranded conductors: 2x (0.5 to 1.5 mm²) or 2x (0.75 to 2.5 mm²) per clamp. The spring-type coil terminal is the same gauge range — no ferrule required but recommended for stranded wire to avoid fraying.
Lifecycle and sourcing posture
The lifecycle stage for 3RT2535-3XF40-0LA2 is listed as current production. No phase-out or last-time-buy notice is attached to this order code. It is sourced and quoted to order against an RFQ through independent distribution — availability and current pricing confirmed at quote time.