S2 frame, 3-pole AC contactor — what fits and what doesn't
The Siemens 3RT7037-1AV00 is a Size S2 contactor carrying three normally-open main poles, rated for AC-3 switching up to 690 V. It mounts via screw and snap-on onto 35 mm DIN rail per EN 50022, with the mounting position allowing ±180° rotation on a vertical surface and ±22.5° tilt forward or backward.
Coil and control — AC drive, DC holding
The control supply voltage is AC. Closing power of the magnet coil at DC is 0.79 W; holding power drops to 0.36 W. The auxiliary contact block is rated for PLC-level reliability (17 V, 5 mA), meaning it can switch low-energy signals without oxide-film issues — useful when feeding a digital input card directly.
Fuse coordination and short-circuit protection
For type of coordination 2 the required backup fuse is gL/gG NH 3NA rated 100 A. For type of coordination 1 it's 160 A.
Both main and auxiliary/control circuits use screw-type terminals. The main circuit accepts 2x (0.5 to 1.5 mm²) or 2x (0.75 to 2.5 mm²) solid or stranded wire, and the same range for finely stranded with core-end processing. Side-by-side mounting is permitted, which helps when packing multiple contactors on a DIN rail.