The Siemens SIRIUS 3RT1024-1BB40 is a size S0 power contactor with a 24 V DC coil, rated for 10 A in AC-12 duty. It carries an IP20 rating on the front and IP00 at the terminals. Operating ambient spans -25 to +60 °C. The coil holds at 5.4 W both closing and holding.
Main circuit terminals accept 2x (0.5...1.5 mm²) solid or 2x (0.75...2.5 mm²) stranded, up to 2x 4 mm² max; auxiliary terminals take 2x (1...2.5 mm²) solid or 2x (2.5...6 mm²) stranded, up to 2x 10 mm². AWG equivalents are 2x (16...12) and 2x (14...10) for mains, 2x (20...16) and 2x (18...14) for aux, with 1x 8 and 1x 12 respectively. Side-by-side mounting is allowed — no derating gap needed.
For type of coordination 2, the required upstream fuse is gL/gG 25 A; for coordination 1, it is gL/gG 63 A. Pollution degree 3 rated, so it suits industrial environments with conductive contamination.