What it is and where it lands
The Siemens 3RT1015-1AL01 is a SIRIUS power contactor in the size S00 frame, designed for switching motor loads and resistive circuits in control panels. It mounts via screw and snap-on onto 35 mm DIN rail per DIN EN 50022, so it drops into any standard industrial enclosure without adapters. The coil is rated at 24 VDC with a pickup range of 0.8 to 1.1 times rated voltage at 50 Hz and 0.85 to 1.1 at 60 Hz, meaning it holds in reliably across brownout conditions down to about 19 V. Rated operational current at 24 V is 10 A, and at 400 V AC-4 duty it carries 6.5 A — that's the switching category for reversing or inching motor loads, where the contactor breaks the full motor current at each cycle.
Key ratings and what they mean for fit
At 690 V the contactor is rated for 4 kW motor power — that's the three-phase line-to-line voltage common in heavy industrial mains. For a 400 V line, the AC-2 rating is 3 kW, which covers wound-rotor motors where the contactor makes and breaks at low current. The AC-12 maximum operating current is 10 A, covering resistive loads like heaters or lighting banks. The auxiliary contact block is a single instantaneous contact (NO or NC depending on wiring). Mechanical life is 30 million operations typical, so this part outlasts most panel cycles before a swap is needed. Side-by-side mounting is allowed with 6 mm spacing — no derating required for adjacent contactors in a group.
Termination and wiring
Main circuit terminals are screw-type, accepting solid or stranded conductors: 2x (0.5 to 1.5 mm²), 2x (0.75 to 2.5 mm²), or max 2x (0.75 to 4 mm²). AWG equivalents are 2x (20 to 16), 2x (18 to 14), and 1x 12. The IP20 finger-safe protection on the front and terminals means it's safe for open-panel mounting where maintenance staff may reach in. For type 2 coordination (no damage to the contactor on a short circuit), the required upstream fuse is gL/gG 20 A. For type 1 coordination (contactor may need replacement after fault), use a 35 A gL/gG fuse. Pollution degree 3 rating suits it for industrial atmospheres with conductive dust or humidity.