Siemens 3RT1024-1BE40 SIRIUS Power Contactor — Integrator's Spec Recap
The Siemens 3RT1024-1BE40 is a SIRIUS power contactor in the Size S0 frame, rated for motor switching up to 7.5 kW at both 500 V and 690 V. It snaps onto a 35 mm DIN rail per EN 50022 and uses screw-type terminals for the main circuit. The 45 mm width and 85 mm height fit standard panel layouts; depth is 101 mm. Front protection is IP20; the terminal area is IP00, so keep fingers clear during wiring. AC-4 switching at 400 V is rated at 12.5 A — that's the severe-duty category for reversing or inching applications. For resistive loads (AC-12), the contactor handles 10 A continuous. The DC coil pulls 5.4 W on close and hold, so the control transformer or PLC output needs to source that without voltage drop.
Mounting and Wiring — Panel OEM Checklist
Mounts via screw or snap-on onto 35 mm DIN rail. Side-by-side mounting is allowed with 6 mm spacing to adjacent devices — no forced air gap required, but keep that clearance for heat rise on continuous duty. The Size S0 footprint is a common panel slot; if you're swapping from another S0 frame contactor, the DIN rail holes and terminal layout should align without drilling. Main circuit terminals accept solid conductors: 2x 0.5–1.5 mm², 2x 0.75–2.5 mm², or max 2x 0.75–4 mm². For stranded wire: 2x 1–2.5 mm², 2x 2.5–6 mm², or max 2x 10 mm². AWG equivalents are 2x 16–12, 2x 14–10, or 1x 8. Strip length and torque values aren't in this spec line — pull the datasheet for those before terminating.
Coordination and Protection — Site Electrical Engineer Note
For Type 2 coordination (no damage to the contactor after a short circuit), the required upstream fuse is gL/gG 25 A. Type 1 coordination (contactor may need replacement after fault) allows a 63 A gL/gG fuse. Pollution degree 3 means it's rated for industrial environments with conductive pollution — standard for most control panels without climate control. Operating temperature range is -25 to +60 °C, with derating likely above 40 °C — the spec doesn't give the curve here, so factor that into continuous current calculations. Maximum altitude is 2000 m without derating; above that, air density affects arc extinction and cooling.