SIRIUS S0 power contactor — 3RT1024-1AG64
The Siemens 3RT1024-1AG64 is a SIRIUS-brand power contactor in the S0 frame size, designed for switching motor loads in industrial control panels. It is rated for 7.5 kW at 400 V AC-3 and also 7.5 kW at 690 V AC-3, making it suitable for 400 V and 690 V line-fed motors up to that power. The coil is 24 VDC, a common control voltage in PLC-driven panels. Mounting is screw or snap-on onto 35 mm DIN rail per EN 50022, which means it drops into a standard panel rail without adapters. The contactor's size S0 footprint — 45 mm wide, 85 mm high, 140 mm deep — fits the compact panel layout typical for motor starters up to 7.5 kW. Side-by-side mounting is allowed with 6 mm spacing, so you can gang multiple contactors on the same rail without derating for heat buildup in a standard enclosure.
Ratings and what they mean for fit
The 7.5 kW rating at 400 V AC-3 is the motor-switching duty that governs most BOM fits — it covers a standard 7.5 kW four-pole induction motor on a 400 V three-phase line. The same 7.5 kW at 690 V AC-3 means the contactor also handles higher-voltage motors common in heavy industrial or mining installations, without stepping up to a larger frame. For resistive loads (AC-1), the contactor carries 10 A continuous at 230 V, which covers heater banks or lighting contactor duty. The AC-4 rating — 12.5 A at 400 V — is the inching/plugging current for frequent reversing or jogging applications. If your application cycles the motor in reverse or does rapid start/stop, this is the rating that determines contact life, not the AC-3 figure. The mechanical life is 10 million operations typical, so it holds up in high-cycle packaging or conveyor indexing lines.
Termination and wiring
Main power terminals are screw-type, accepting 2x (1 to 2.5 mm²) or 2x (2.5 to 6 mm²) stranded, with a maximum of 2x 10 mm². Solid wire range is 2x (0.5 to 1.5 mm²) or 2x (0.75 to 2.5 mm²), up to 2x 4 mm² max. AWG equivalents are 2x (16 to 12) or 2x (14 to 10) stranded, with a single 8 AWG maximum. The auxiliary contact block has its own terminal specs — 2x (0.5 to 1.5 mm²) solid or 2x (0.75 to 2.5 mm²) stranded. Protection degree is IP20 on the front (finger-safe) and IP00 at the terminals — meaning the terminal area is not touch-safe once wired. The contactor is rated for pollution degree 3, so it is suited for control panels in industrial environments with conductive dust or condensation, not just clean rooms.
Environmental and coordination
Operating temperature range is -25 °C to +60 °C during operation, which covers most indoor panel environments even near ovens or in unheated warehouses. Maximum operating altitude is 2,000 m without derating — above that, consult the thermal derating curve for the specific installation. For short-circuit coordination, the contactor requires a gL/gG fuse: 25 A for type 2 coordination (no damage to the contactor) and 63 A for type 1 coordination (contactor may need replacement after a fault). Voltage tolerance on the coil is 0.8 to 1.1 x rated at 50 Hz, and 0.85 to 1.1 at 60 Hz — so the 24 VDC coil holds in during brownout conditions down to about 19.2 V.