The Siemens 3RT1026-1BB40-ZW97 is a SIRIUS S0-frame power contactor with a 24 VDC magnet coil, rated for motor switching at 11 kW on 400 V AC-3 duty and also 11 kW at 500 V and 690 V. It uses screw-type terminals for the main circuit and mounts via screw or snap-on onto a 35 mm DIN rail per EN 50022 — the S0 frame keeps the footprint compact at 45 mm wide, 85 mm tall, and 101 mm deep.
Ratings and what they mean for fit
The 24 VDC coil draws 5.4 W on both closing and holding — a steady-state load that matters for DC supply sizing in a panel with multiple contactors. The AC-3 motor rating of 11 kW at 400 V is the number that governs most three-phase motor switching; the same contactor also carries 11 kW at 500 V and 690 V, so it handles higher-voltage motors without derating the power. For resistive or general-purpose loads, the AC-12 rating tops out at 10 A. Switching capacity on the DC side covers control-circuit loads: 10 A at 24 V, 2 A at 60 V, 1 A at 110 V, and 0.3 A at 220 V. The AC-4 rating at 400 V is 15.5 A — that's the inching or plugging duty cycle, lower than AC-3 because of the heavier arc stress during frequent reversals. The front face carries IP20 protection — safe for finger contact inside an enclosure. The terminal area is rated IP00, meaning the live parts are exposed; the contactor must be mounted inside a panel or enclosure that provides the final protection. Pollution degree 3 means it's suited for industrial environments with conductive dust or occasional condensation. Mechanical endurance is rated at 10 million operating cycles — that's the contactor mechanism itself, not the electrical life under load. The operating temperature range of -25 to +60 °C covers most indoor industrial panels, though the coil's minimum pickup voltage (0.8 × rated) and dropout (0.1 × rated) should be checked against the actual DC supply regulation.
Mounting and wiring
Snap-on mounting onto a 35 mm DIN rail per EN 50022 is the standard method; screw mounting is also possible. Side-by-side mounting is allowed with a 6 mm gap to the side — no derating mentioned for adjacent units, but the gap ensures airflow. The main circuit screw terminals accept 2x (1 to 2.5 mm²) solid or stranded, up to 2x 10 mm² maximum. The auxiliary/coil terminals take 2x (0.5 to 1.5 mm²) solid, up to 2x 4 mm². AWG equivalents are 2x (16 to 12) for the main and 2x (16 to 14) for the coil circuit.
Coordination and protection
For Type 2 coordination (no damage to the contactor under short circuit), the required upstream fuse is gL/gG 35 A. For Type 1 coordination (contactor may be damaged but no hazard to personnel), the fuse can be gL/gG 100 A. These values guide the selection of branch-circuit protection in the panel.