What it is and what it does
The Siemens 3RT1026-1AK64 is a SIRIUS power contactor in the S0 frame size, designed for switching motor loads in industrial control panels. It mounts on a 35 mm DIN rail per EN 50022 using either screws or a snap-on clip, and the main circuit connects via screw-type terminals. Rated for 11 kW at 400 V in AC-3 duty, this contactor handles the inrush of a standard three-phase induction motor up to that power level. The same 11 kW rating at 690 V means it can serve higher-voltage motor circuits without derating the power throughput. The contactor carries a mechanical service life of 10 million operations, which suits applications with frequent switching cycles like conveyor systems or pump controls.
Key ratings and what they mean for fit
The AC-4 rating of 15.5 A at 400 V is the one to watch for plugging or inching duty — that's the current the contactor can interrupt during frequent motor reversals or jogging, not just steady-state running. For type 2 coordination (no weld after a short circuit), the upstream fuse must be gL/gG rated at 35 A. For type 1 coordination (device may be damaged but no fire risk), a 100 A gL/gG fuse is the limit. This matters when the contactor sits in a panel with a high-fault-capacity bus. The auxiliary contact block provides 2 instantaneous contacts, which is enough for a basic feedback circuit to a PLC or a holding contact for the coil. Operating temperature range of -25 to +60 °C covers most indoor panel environments, and the IP20 front protection means it's safe for finger contact in a closed enclosure. The terminal area is IP00 — no touch protection there, so panel wiring must be behind a door or cover.
Mounting and wiring
Width is 45 mm, height 85 mm, depth 140 mm. Side-by-side mounting is permitted with zero spacing — the 6 mm side clearance listed is for heat dissipation when mounted individually, but the contactor is designed for zero-gap grouping on the rail. Main circuit terminals accept 2x (1 to 2.5 mm²) or 2x (2.5 to 6 mm²) stranded, or up to 2x 10 mm² solid. The auxiliary circuit terminals take 2x (0.5 to 1.5 mm²) or 2x (0.75 to 2.5 mm²) solid, with a maximum of 2x (0.75 to 4 mm²). AWG equivalents are 2x (16 to 12) or 2x (14 to 10) for main, and 1x 8 for a single larger conductor.
Lifecycle and sourcing
Pollution degree 3 rating means it's suitable for industrial environments with conductive dust or occasional condensation, typical of most factory-floor panels.