The Siemens SIRIUS 3RT2037-1NB34-3MA0 is an S2-frame power contactor rated for a 20-33 VDC coil with screw-type terminals. It mounts on 35 mm DIN rail per DIN EN 60715 and accepts +/-180° rotation on a vertical surface, plus +/-22.5° tilt forward/backward — handy when you're squeezing it into a tight panel and need to angle the wiring access.
What the ratings mean for fit
The S2 frame size tells you the physical envelope and the contactor's current-handling class — it's the middle frame in the SIRIUS line, bigger than S0, smaller than S3. The 20-33 VDC coil range means it pulls in reliably at 20 V and holds through dips up to 33 V; inrush peak is 3 A, so your 24 VDC supply needs to handle that surge without droop. The coil's operating power is 2 VA at both 50 and 60 Hz, which is low enough that a standard PLC output can drive it through an interposing relay.
Where it goes in a panel
This contactor is built for motor switching in control panels — think conveyors, pumps, fans, compressors on 400 V three-phase lines. The screw-type coil terminals accept 2x (0.5 to 1.5 mm²) or 2x (0.75 to 2.5 mm²) solid or stranded wire, so it plays nice with standard panel wiring. The physical footprint is 55 mm wide, 114 mm tall, 174 mm deep — that's about two standard MCB widths on the DIN rail, leaving room for overload relays and busbars in the same row.
Lifecycle and sourcing reality
This part is listed as current production. It is a standard BOM line item. We source it to order against an RFQ; availability and pricing are confirmed at quote time.