The Siemens 3RT2037-3AB00 is a SIRIUS S2-frame power contactor rated for 65 A at 480 V AC-3 duty — that's the motor-switching current for a load up to about 30 kW at 480 V three-phase, so it handles a 40 hp motor in a 480 V plant without a derate. Spring-type terminals on the coil and main contacts accept 2x 0.5...2.5 mm² solid or stranded, which covers most panel wiring up to 14 AWG. Fastening is screw and snap-on onto 35 mm DIN rail per DIN EN 60715, with mounting position flexibility: +/-180° rotation on a vertical surface and +/-22.5° tilt forward/backward, so it fits tight enclosures without a special bracket.
Switching duty and mechanical life
Maximum switching rates: 800 cycles/hour at AC-1 (resistive loads), 700 at AC-3 (standard motor starts), and 200 at AC-4 (plugging/reversing). The auxiliary switch is built in — 1 NO + 1 NC configuration, rated 10 A at 24 V, 2 A at 48/60 V, tapering to 0.3 A at 220 V.
Clearances and environment
Dimensions: 114 mm high, 55 mm wide, 130 mm deep. Side clearance to adjacent devices is 6 mm; forward/upward/downward clearance is 10 mm each. Arcing time is 10...20 ms — the arc extinguishes fast enough that standard 10 mm phase barriers in a panel are sufficient.
Lifecycle status is current production — this is not an NRND or discontinued line. The 3RT2037-3AB00 is an active catalog item from Siemens SIRIUS.