What This Part Is
The Siemens 3RT2037-1NB30 is an S2-frame SIRIUS power contactor, current production, with a coil rated from 20 to 33 V. The contactor switches motor loads up to the AC-3 duty cycle it's designed for, and the screw-terminal main contacts accept up to 2 × 2.5 mm² conductors.
Mounting & Envelope
Mounts via screw or snap-on on 35 mm DIN rail per EN 60715. The housing is 114 mm high, 55 mm wide, and 130 mm deep. Side clearance is 6 mm; vertical spacing above and below is 10 mm each. The contactor accepts up to ±180° rotation on a vertical surface and ±22.5° tilt forward/backward.