What this contactor is and what it does
The Siemens 3RT1026-1XP00-0GA0 is a SIRIUS power contactor in the compact Size S0 frame — 45 mm wide, 116 mm tall, 101 mm deep — designed for screw and snap-on mounting onto 35 mm DIN rail per EN 50022. It switches motor loads up to 11 kW in AC-2 duty at 400 V, and handles 15.5 A in AC-4 (reversing or inching) at the same voltage. The built-in varistor surge suppressor is already wired across the coil, so you don't need to add a separate snubber for inductive load switching.
Key ratings and what they mean for fit
The AC-2 rating of 11 kW at 400 V covers slip-ring motor starting — the contactor sees moderate inrush but makes and breaks under load. For plugging or jogging duty (AC-4), the 15.5 A limit at 400 V is the one to watch; exceed that and the contacts will erode faster than expected. The auxiliary contact ratings are given per voltage: 10 A at 24 V, 6 A at 230 V, 3 A at 400 V — so the 24 V control circuit can handle a full 10 A through the aux contacts without derating. Ambient range is -25 to +60 °C, with pollution degree 3 (conductive pollution or dry non-conductive that becomes conductive — typical in industrial panels near machinery).
Coordination and protection
For Type 1 coordination (no weld prevention, just no fire or shock hazard after a short), the upstream fuse can be gL/gG 100 A. For Type 2 coordination (contactor remains usable after a fault), drop to gL/gG 35 A. The screw terminals accept 2x 0.75 to 4 mm² on the control side, and 2x 1 to 10 mm² on the main circuit — AWG equivalents are 2x 16-12 and 2x 14-10 respectively. Side-by-side mounting is allowed with 6 mm spacing to adjacent devices.