What it is and what it does
The Siemens 3RT1026-3AV00 is a SIRIUS S0-frame power contactor with three normally-open main contacts and screw-type terminals. It is rated for 11 kW motor loads at 400 V 50 Hz in AC-3 duty, and the same power at 690 V, making it a fit for standard three-phase induction motors on pumps, fans, and conveyors in panel builds.
Mounting and integration
Mounts via screw or snap-on onto 35 mm DIN rail per EN 50022. The 45 mm width and 85 mm height fit a standard S0 footprint; depth is 90 mm, which leaves room for wiring ducts on a 200 mm deep enclosure. Side-by-side mounting is allowed with no gap, but check the 6 mm clearance to grounded metal on the front face (IP20 finger-safe on the front, IP00 at the terminals).
Duty ratings and coordination
AC-3 rating: 11 kW at 400 V. AC-2 (slip-ring motor) also 11 kW at 400 V. AC-4 (plugging / inching) is 15.5 A at 400 V — that is the duty cycle limit for reversing or jogging applications. For type 2 coordination (no weld under fault) use a 35 A gL/gG fuse; type 1 allows a 100 A fuse upstream. The auxiliary contact block (not included) switches 10 A at 24 V DC, 6 A at 230 V, and down to 0.3 A at 220 V DC — enough for a PLC input or indicator lamp.