What this part is and where it fits
The Siemens 3RT1374-6AF36 is a SIRIUS contactor in size S12, meaning it's built for switching motor loads and other inductive or resistive circuits in a control panel. The S12 frame is a common footprint in European-style panels, and this one carries a 48-130 V AC coil — that's the voltage range the coil will pull in at, not the main contact rating. The coil draws 17 VA at both 50 and 60 Hz, so the control transformer sizing is straightforward across line frequencies. It's a screw-fixing mount, not a DIN-rail snap-on, so you'll be bolting it to a backplate or mounting rail. The mounting position is flexible: vertical surface, can be rotated ±180°, and with 0° rotation can be tilted forward or backward ±30°, or standing. That gives you some layout freedom in a crowded cabinet.
Key ratings and what they mean for your panel
The coil pickup voltage is 0.8 x rated value, and dropout is 1.1 x rated value — so on a 110 V AC control circuit, the coil will pick up at about 88 V and drop out around 121 V. That's a standard margin for AC contactors, but worth checking if your control voltage sags under load. The auxiliary contact block is built in — 2 instantaneous contacts, rated at 24 V (3 A), 48 V (1.5 A), 110/125 V (0.55 A), 220 V (0.3 A), 230 V (4 A), 400 V (3 A), 500 V (2 A), and 690 V (2 A). Those are the switching capacities for the aux contacts, not the main poles. The 4 A at 230 V is the highest figure, so if you're switching a 230 V pilot light or PLC input, that's your limit per contact. Operating times are 45-80 ms for both AC and DC operation — that's the range for the main contacts to close or open. Not a fast-switching device, but typical for a contactor this size. The coil terminal type is screw-type, and the wire range accepts 1x or 2x conductors from 1 to 4 mm² solid or stranded.
Physical fit and clearances
Dimensions: 225 mm high, 184 mm wide, 180 mm deep. That depth is the body depth, not including any protruding terminals or arc chutes — check your enclosure depth against that figure. Required clearances: 10 mm upwards and downwards, 20 mm forwards, 10 mm at the sides. That's for heat dissipation and arc flash clearance, not just air flow. Operating temperature range is -40 to +60 °C, storage is -40 to +70 °C. That covers most indoor industrial environments, including unheated warehouses. The contactor can handle up to 2 attachable auxiliary blocks if you need more than the built-in 2 contacts.
Sourcing and lifecycle
Because it's active, sourcing is straightforward — quoted to order against an RFQ. No need to hunt surplus or broker channels. The SIRIUS series is widely stocked, and the S12 frame is a common size, so lead times are typically manageable through distribution.