What it is and what it does
The 3RT2646-1NP35 is a Siemens SIRIUS contactor with an AC/DC-operated magnet coil and screw-type terminals for the coil connection. It's built for switching loads in industrial control panels — the kind of part you spec into a motor starter or a lighting contactor bank and forget about, as long as the ratings line up. The coil accepts 175–280 V AC at 50/60 Hz, with a pickup range of 0.8 to 1.1 times rated voltage. That initial pickup threshold of 0.8 means it's forgiving on a sagging line — useful when you're pulling from a shared transformer or a long cable run. Switching times are consistent across AC and DC: 38–57 ms for both opening and closing. That's a standard range for a contactor this size — nothing to trip over on a sequencing logic check, but worth noting if you're coordinating with a fast-acting upstream breaker. The main contacts are rated for 6 A at 24 V and 230 V, 3 A at 400 V, and derate to 0 A at 690 V — meaning this is not a 690 V switching device. For motor loads, the 400 V 3 A rating tells you it's sized for smaller motors or resistive loads; the 230 V 6 A rating is the headline figure for most panel builders.
Mounting and integration
Mounts via screw or snap-on onto 35 mm DIN rail per DIN EN 50022. The mounting position is flexible: ±180° rotation on a vertical surface, plus ±22.5° tilt forward or backward. That means you can shoehorn it into a tight cabinet corner or a slanted sub-panel without a custom bracket. Dimensions are 80 mm wide, 140 mm high, 152 mm deep — a standard three-pole contactor footprint. It'll fit in most pre-punched backplates and leaves room for auxiliary contact blocks on the side or top. One attachable auxiliary contact block is supported. If you need more than one, you're looking at a different base contactor or an external interposing relay.
Termination and wiring
The coil connection uses screw-type terminals. Main circuit terminals accept solid conductors: 2x 0.5–1.5 mm², 2x 0.75–2.5 mm², or 2x 4 mm². For stranded: 2x 10–70 mm² or 1x 10–70 mm². That's a wide range — you can land a 70 mm² feeder on one side and a 1.5 mm² control wire on the other, which is handy for mixed-load panels. At 40 °C ambient, the terminal accepts 1x 70 mm²; at 60 °C, derate to 2x 50 mm². The thermal curve is baked into the terminal rating — no separate derating calculation needed for the wire termination itself.
Environmental and lifecycle
Operating ambient temperature range is -25 to +60 °C; storage range is -55 to +80 °C. The storage range is wider than operating — that's typical for shipping and warehouse conditions, not for running the contactor under load.