SIRIUS 3RT1024-1AL20-ZW97 — Power Contactor, Size S0
The Siemens SIRIUS 3RT1024-1AL20-ZW97 is a Size S0 power contactor with screw-type terminals, designed for motor switching and general load control in industrial panels. It mounts on a 35 mm DIN rail per DIN EN 50022 — screw and snap-on — so it fits standard enclosure layouts without extra bracketry. Rated for AC-4 duty at 12.5 A at 400 V, this contactor handles the severe switching of reversing or inching motor loads where the contacts make and break stalled-rotor current. For AC-2 duty (slip-ring motors) it carries 5.5 kW at 400 V. At 500 V and 690 V it delivers 7.5 kW each, covering common European line voltages. The 50/60 Hz coil tolerance (0.8–1.1 at 50 Hz, 0.85–1.1 at 60 Hz) means it holds in on brownout conditions down to 80% of nominal at 50 Hz. Operating temperature spans -25 to +60 °C, and the IP20 front / IP00 terminal protection suits panel-mount installations where the contactor is behind a gland plate or enclosure door.
Termination and Wiring
Main circuit terminals accept solid or stranded conductors: 2x (0.5–1.5 mm²), 2x (0.75–2.5 mm²), max 2x (0.75–4 mm²) for the smaller range, and 2x (1–2.5 mm²), 2x (2.5–6 mm²), max 2x 10 mm² for the larger. AWG equivalents: 2x (16–12), 2x (14–10), 1x 8. These ratings cover common control and power wiring sizes used in European and North American panels. Side-by-side mounting is permitted (zero gap), saving rail space. The 45 mm width and 85 mm height keep the footprint compact for dense panel layouts. Depth is 91 mm — enough to clear the terminals and arc chamber but standard for the S0 frame.
Coordination and Protection
For Type 1 coordination (no damage to the contactor but may need contact replacement), the required upstream fuse is gL/gG 63 A. For Type 2 coordination (limited weld risk, no damage), use gL/gG 25 A. These values assume a prospective fault current typical of industrial distribution. Pollution degree 3 (conductive pollution or dry non-conductive that becomes conductive due to condensation) means it's suited for control panels in factory environments, not clean rooms. Maximum operating altitude is 2 000 m without derating.