Siemens 3RT1026-3BB48-0PB0 — SIRIUS S0 Power Contactor, 24 VDC Coil
The Siemens SIRIUS 3RT1026-3BB48-0PB0 is a size S0 power contactor with a 24 V DC coil, designed for switching motor loads in control panels. It mounts via screw or snap-on onto 35 mm DIN rail per EN 50022, fitting the standard panel footprint at 55 mm wide, 85 mm tall, and 101 mm deep. Rated for 11 kW at AC-2 duty on 400 V (the standard motor-switching category for slip-ring motors and moderate overloads), and 15.5 A at AC-4 at 400 V for reversing or inching applications where the contactor makes and breaks full load current. The DC coil draws 5.4 W both during pickup and holding, so the control transformer and wiring need only size for that steady draw — no inrush spike to design around. Mechanical life is rated at 10 million operations typical, which for a conveyor or pump contactor cycling a few times per hour means decades of service before wear-out. The IP20 front enclosure protects against finger contact in the panel; the terminals themselves are IP00, so live parts are exposed during wiring — standard for panel-mount contactors.
Switching Capacity and Coordination
For DC load switching, the contactor handles 10 A at 24 V, 2 A at 60 V, 1 A at 110 V, and 0.3 A at 220 V — useful for breaking DC control circuits or small DC motor loads within those limits. On AC loads, the AC-1 rating (resistive) is 10 A maximum. Short-circuit coordination: with Type 2 assignment (minimal damage to the contactor after a fault), use a gL/gG fuse rated 35 A. For Type 1 coordination (contactor may need replacement after fault), the fuse can be 100 A. The contactor has one normally-open instantaneous main contact. Screw terminals on the main circuit accept 2x (0.25 to 2.5 mm²) solid, 2x (1 to 2.5 mm²) or 2x (2.5 to 6 mm²) stranded, and up to 2x 10 mm² maximum. AWG equivalents: 2x (16 to 12), 2x (14 to 10), and 1x 8. Side-by-side mounting is permitted without derating, with a 6 mm clearance to adjacent devices on the side.
Environmental and Installation
Operating temperature range is -25 to +60 °C, covering most indoor industrial environments. Rated for installation altitudes up to 2,000 m without derating. Pollution degree 3 (conductive pollution or dry non-conductive that becomes conductive due to condensation) — typical for control panels in factory floors or utility rooms.