Integrator note — SIRIUS S0 power contactor
The Siemens 3RT1026-1AP05 is a SIRIUS S0-frame power contactor with three normally-open main contacts and zero NC main contacts. It is rated for AC-12 duty at 10 A (resistive loads on control circuits) and can switch motor loads in AC-2 at 11 kW at 400 V or handle AC-4 reversing duty at 15.5 A at 400 V. The contactor mounts via screw or snap-on onto 35 mm DIN rail per DIN EN 50022, and the S0 footprint — 55 mm wide, 85 mm tall, 91 mm deep — fits standard panel layouts. Side-by-side mounting is permitted, so multiple units pack tightly on the rail.
Termination and wiring
Main current circuit connections use screw-type terminals. The solid/stranded wire range for main contacts accepts 2x (1 to 2.5 mm²), 2x (2.5 to 6 mm²), or max 2x 10 mm²; AWG equivalents are 2x (16 to 12), 2x (14 to 10), or 1x 8. Auxiliary/control circuit terminals accept 2x (0.5 to 1.5 mm²), 2x (0.75 to 2.5 mm²), or max 2x (0.75 to 4 mm²). The front face carries IP20 protection; the terminal area is IP00, so maintain clearance in the panel.
Coordination and protection
For type 1 coordination (no damage to the contactor after a short circuit, but it may need replacement), the required upstream fuse is gL/gG 100 A. For type 2 coordination (contactor remains operational after a fault), use a gL/gG 35 A fuse. These ratings apply to the main circuit and let you size the branch protection correctly.