SIRIUS S0 power contactor — 24 VDC coil, 11 kW at 400 V
The Siemens 3RT1026-1BB44-1AA0 is a SIRIUS S0-frame power contactor rated for 11 kW at 400 V in AC-3 duty and the same 11 kW at 690 V, making it a fit for three-phase motor loads up to that power class across standard European supply voltages. The coil is 24 VDC, drawing 5.4 W on pickup and 5.4 W holding — a constant-hold design that simplifies the DC supply sizing since there is no dropout between seal-in and hold. Mounting is screw-and-snap-on onto a 35 mm DIN rail per EN 50022, with side-by-side mounting permitted. The S0 frame keeps the footprint compact at 45 mm wide, 85 mm tall, and 150 mm deep — a space-efficient choice for crowded control panels where every DIN-width unit counts. The front face carries IP20 protection; the terminal area is IP00, which is standard for screw-type power terminals inside an enclosure. Pollution degree 3 (conductive pollution or dry non-conductive with condensation) means it is suited for industrial environments where the panel is not climate-controlled.
Motor switching and coordination
Beyond the AC-3 motor rating, the contactor is rated for AC-4 duty at 15.5 A at 400 V — the category for plugging and inching where the contacts make and break stalled-rotor currents. AC-2 at 400 V also carries 11 kW, covering slip-ring motor starting. For resistive or lightly inductive loads (AC-12), the maximum operating current is 10 A. Short-circuit coordination is specified: type 1 coordination requires a 100 A gL/gG fuse; type 2 coordination requires a 35 A gL/gG fuse. This lets the panel designer choose between simpler replacement after a fault (type 1) or minimal contact damage (type 2) depending on the line's uptime requirements. Mechanical endurance is rated at 10 million operating cycles typical, which aligns with the S0 frame's position as a workhorse for moderate-duty switching applications.
Auxiliary contact block and coil data
The contactor carries 2 instantaneous auxiliary contacts (NO/NC configuration not specified in the base code — the 1AA0 suffix typically indicates a specific auxiliary block variant; verify the contact arrangement against your schematic). The coil's DC switching capacity is rated at 10 A at 24 V, 2 A at 60 V, 1 A at 110 V, and 0.3 A at 220 V — these are the maximum currents the auxiliary contacts can switch in DC control circuits, which matters when driving PLC outputs or relay loads. Terminals accept solid or stranded conductors: main circuit terminals take 2x (1 to 2.5 mm²), 2x (2.5 to 6 mm²), or max 2x 10 mm²; auxiliary circuit terminals take 2x (0.5 to 1.5 mm²), 2x (0.75 to 2.5 mm²), or max 2x (0.75 to 4 mm²). AWG equivalents are 2x (16 to 12), 2x (14 to 10), and 1x 8 for the main circuit. The screw-type terminals are standard for panel wiring.
Lifecycle and sourcing
For procurement: this part is sourced and quoted to order against an RFQ through independent distribution. Availability and current pricing are confirmed at quote time. The active lifecycle means no special surplus-channel search is needed — it is a straightforward BOM line item.