The Siemens 3RT2038-1AH20 is a SIRIUS Size S2 power contactor rated for 65 A at 480 V in AC-3 duty — that's the motor-switching current, not the resistive-heater number. It carries an auxiliary switch built in, and the coil termination is screw-type, so no special crimp tool on the panel bench.
Panel fit and mounting
Mounts via screw and snap-on onto 35 mm DIN rail per DIN EN 60715. The body is 55 mm wide, 114 mm tall, 130 mm deep — that's a standard S2 footprint, so it lines up with the rest of the SIRIUS 3RT2 family on the rail. You can rotate it ±180° on a vertical surface or tilt it forward/backward ±22.5° if the gland plate forces an odd angle. Clearance: 10 mm up, down, and forward; 6 mm to the side.
Switching capacity and life
This contactor's AC-3 rating is 65 A at 480 V — that's the motor load it'll switch day in, day out. AC-4 (plugging/inching) drops to 150 operations per hour maximum, while AC-3 runs at 500 ops/hr and AC-1 (resistive) at 700 ops/hr. Mechanical life is typical 10 million operations. Arcing time runs 10 to 20 ms; closing time 10 to 18 ms at AC coil.
Coil and auxiliary specs
The auxiliary switch is included from the factory — no add-on module to order separately for basic signaling. Coil voltage and frequency are specified for 50 Hz (0.36 A) and 60 Hz (0.39 A) at 48 V. The contactor also carries rated switching capacities at 24 V (10 A), 48 V (2 A), 60 V (2 A), 110 V (1 A), 125 V (0.9 A), 220 V (0.3 A), 400 V (3 A), and 440 V (0.6 A) — useful if you're running the auxiliary contacts at a different voltage than the main power.
Environmental limits
Operating temperature range is -25 °C to +60 °C; storage range is -55 °C to +80 °C. Main contacts rated 18 to 1.