Sourcing note for this SIRIUS S0 contactor
The 3RT1025-3KK84-0LA0 is a current-production SIRIUS power contactor in the S0 frame size. It's a standard fast mover for motor control panels — the kind of part you keep on the shelf for line-down spares. The built-in varistor surge suppressor means you don't need to spec a separate RC snubber for the coil, which saves a terminal slot on the rail.
Motor duty ratings — what they mean for the BOM line
AC-3 motor switching is the headline: 11 kW at 690 V and 10 kW at 500 V. That covers most 400 V class motors up to about 15 kW when you account for the typical 0.75 power factor. The AC-4 rating at 400 V is 15.5 A — that's the inching/jogging duty cycle, so if your application does frequent plugging or reversing, this is the number that governs contact life, not the AC-3 figure. For resistive loads (AC-1), the maximum operating current is 10 A at AC-12.
Panel fit and wiring
Mounts via screw or snap-on onto 35 mm DIN rail per EN 50022. The S0 frame is 70 mm wide, 88 mm tall, 153 mm deep — that's a common footprint that drops into most existing panels without re-drilling. Side-by-side mounting is allowed with 6 mm clearance at the side. Main terminals are screw-type, accepting 2x (1 to 2.5 mm²) solid or stranded, up to 2x 10 mm² max. AWG equivalents are 2x (16 to 12) solid, 2x (14 to 10) stranded. For Type 2 coordination (no weld-sticking under fault), spec a gL/gG 25 A fuse upstream; for Type 1 (replace contactor after fault), a 63 A fuse is the limit.
Environmental and coil data
Rated insulation voltage is 52 V. Operating temperature range is -40 to +70 °C, which covers unheated enclosures in northern climates. Pollution degree 3 means it's rated for industrial environments with conductive dust or condensation — no need for an additional conformal coating in most panels. The front face carries IP20 (finger-safe), while the terminal area is IP00 (open). Coil closing power is 23 W DC, holding at 7 W DC — the varistor handles the inductive kick.