SIRIUS S0 power contactor for motor and resistive loads
The Siemens 3RT1025-1BB48-0QA2 is a SIRIUS S0-size power contactor with a 24 VDC coil, 3 main poles, and screw-type terminals. It mounts via screw or snap-on onto 35 mm DIN rail per EN 50022, fitting standard panel layouts. The contactor is rated for AC-3 motor switching: 10 kW at 500 V and 11 kW at 690 V, with an AC-4 rated operational current of 15.5 A at 400 V for reversing or inching duty. The coil draws 5.4 W for both closing and holding, so the DC supply sees a steady load once picked up.
Coordination and protection
For Type 2 coordination (no damage to the contactor under short circuit), the upstream fuse must be gL/gG 25 A. Type 1 coordination allows a 63 A gL/gG fuse, which permits the contactor to be replaced after a fault. The pollution degree is 3 (conductive pollution or dry non-conductive pollution that becomes conductive due to condensation), typical for industrial control panels. Side-by-side mounting is permitted without derating, saving rail space — but maintain the 6 mm side clearance to adjacent devices for heat dissipation.
Termination and wiring
Main circuit terminals accept solid conductors: 2x (0.5–1.5 mm²), 2x (0.75–2.5 mm²), max 2x (0.75–4 mm²). For stranded or ferruled wire: 2x (1–2.5 mm²), 2x (2.5–6 mm²), max 2x 10 mm². AWG equivalents: 2x (16–12), 2x (14–10), 1x 8. The auxiliary contact block (3RT1025-1BB48-0QA2 includes one instantaneous N/O + N/C) has its own terminal ratings. The front face carries IP20; the terminal area is IP00 — keep live parts behind a panel door or cover.