What it is and where it fits
The Siemens 3RT2045-1NB30 is a SIRIUS power contactor, size S3, designed for switching motor loads in industrial control panels. It mounts via screw or snap-on onto 35 mm DIN rail per DIN EN 60715, with ±180° rotation and ±22.5° tilt on vertical surfaces, giving panel builders flexibility in tight enclosures.
Key ratings and what they mean
The coil is rated 20-33 VDC with a 6.5 A inrush peak and a holding power of 3.5 VA at both 50 and 60 Hz. That inrush matters for DC-supply sizing — expect a brief 6.5 A spike on pickup, then settle to the VA draw. Switching rates vary by duty: AC-3 (motor start/run) allows up to 1,000 operations/hour, AC-1 (resistive) 900/h, AC-2 (slip-ring) 400/h, and AC-4 (plugging/inching) 300/h. For high-cycle motor switching, the AC-3 rate is the one to watch.
Termination and wiring
Main contacts accept solid wire 2.5-16 mm² or stranded 6-70 mm²; auxiliary terminals take 2x (0.5-1.5 mm²) or 2x (0.75-2.5 mm²). All connections are screw-type terminals — no special tooling needed, but torque to spec for the wire range used.
Lifecycle and sourcing
The lifecycle stage is listed as current production. For BOM-line sourcing, this part is quoted to order against an RFQ through independent distribution — availability and current pricing confirmed at quote time. No official successor has been issued, so this remains the direct fit for any panel specified with the 3RT2045-1NB30.