What this SIRIUS S0 contactor carries
The Siemens 3RT1025-1AK60-ZX95 is a SIRIUS power contactor in the S0 frame size, built for motor switching and resistive load control in industrial panels. Its AC-2 rating at 400 V delivers 7.5 kW — that's the duty cycle for slip-ring motors or wound-rotor applications where starting current stays moderate. For plugging or inching duty (AC-4), it holds 15.5 A at 400 V, which is the number to size against for reversing or jogging circuits. Mounting is screw-and-snap-on onto 35 mm DIN rail per EN 50022, so it drops into any standard panel rail without adapters. The 45 mm width and 85 mm height keep it tight for multi-contactor groups; depth runs 91 mm, which matters when the enclosure backplate-to-door clearance is tight. Coordination flexibility is built in: with type 2 coordination (no weld-stick after a fault) the required upstream fuse is 25 A gL/gG; with type 1 coordination (device may be damaged but clears the fault) it accepts up to 63 A gL/gG. That gives the panel designer a choice between tighter protection or higher fault-clearing capacity depending on the branch circuit.
Terminal and wiring detail
Main current circuit terminals are screw-type, accepting solid or stranded conductors: 2x (0.5 to 1.5 mm²), 2x (0.75 to 2.5 mm²), and max 2x (0.75 to 4 mm²). For AWG, that translates to 2x (16 to 12), 2x (14 to 10), and 1x 8. The auxiliary contact block (if fitted) shares the same terminal style — no special crimp tooling needed beyond standard screwdriver-termination practice.
Environmental and mounting constraints
Operating temperature range is -25 to +60 °C during operation, with a degree of pollution 3 rating (conductive pollution or dry non-conductive that becomes conductive due to condensation). That means it's suited for industrial environments where the panel isn't sealed clean — think machine shops, conveyor lines, or packaging floors. Maximum operating altitude is 2,000 m without derating; above that, dielectric strength drops and you'd need to factor in air-gap clearance adjustments. Side-by-side mounting is permitted without derating at the rated current, which simplifies multi-contactor assemblies. The 6 mm clearance at the side is the minimum for heat dissipation when mounting adjacent units.
Coil and control circuit ratings
The coil operates across 0.8 to 1.1 times the rated voltage at both 50 Hz and 60 Hz, giving a pickup range that handles typical line sag without nuisance dropout. Rated control supply voltages are 110 V at 50 Hz and 120 V at 60 Hz. Switching capacity on the auxiliary contacts covers 10 A at 24 V, 6 A at 230 V, and 3 A at 400 V — enough for direct PLC input drive or small relay loads without an interposing relay.