SIRIUS S2 power contactor — 65 A AC-3 at 480 V
The Siemens 3RT2037-3AK60 is a SIRIUS S2 power contactor rated 65 A in AC-3 duty at 480 V, sized for switching three-phase motor loads up to that current in a control panel. The S2 frame (114 mm high, 55 mm wide, 130 mm deep) 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 — useful when panel layout forces an unconventional orientation.
Duty-cycle and switching frequency
Maximum switching rates vary by duty: 800 cycles/hour in AC-1 (resistive), 700 in AC-3 (motor run), 400 in AC-2 (slip-ring motor start), and 200 in AC-4 (plugging/inching). The AC-3e rating matches the standard AC-3 at 700 cycles/hour. For a conveyor or pump running continuous starts, stay within the AC-3 limit; the AC-4 figure governs reversing or jogging applications where contact wear accelerates.
Coil termination and auxiliary contacts
The magnet coil terminates to spring-type (cage-clamp) terminals accepting 2x 0.5–2.5 mm² solid or stranded — no screw torque to verify, just strip to 8 mm and insert. Main contacts are configurable from 18 NO to 1 NC (or any combination in between), giving flexibility for three-pole motor circuits with spare auxiliaries for status feedback.
Environmental and clearance
Minimum air clearances: 10 mm upward, forward, and downward; 6 mm to the side. The 10 mm arcing time window (10–20 ms) and 10–18 ms AC switching time are within standard for this contactor class — no special arc-chamber venting required in a typical IP20 panel.