Siemens SIRIUS 3RT2037-3CL24-3MA0 — Size S2 Power Contactor
The Siemens SIRIUS 3RT2037-3CL24-3MA0 is a Size S2 power contactor rated for 65 A in AC-3 duty at 480 V — the motor-switching current that determines real-world fit for three-phase induction motors up to that load. Spring-cage terminals on the coil and main contacts accept 2x (0.5 to 2.5 mm²) solid or stranded conductors, a wiring preference for panels where vibration resistance matters over screw-clamp retention.
Mechanical & Environmental Clearances
Minimum air clearances around the contactor: 10 mm upwards, downwards, and forwards; 6 mm at the sides. These govern how tightly you can pack multiple units on a DIN rail without forced derating. The storage limit governs handling during transport and off-season warehousing, not running conditions.
Switching Performance & Coil Data
Arcing time spans 10 to 20 ms; the coil's make/break duration is 10 to 18 ms at AC — relevant when coordinating contactor timing with upstream short-circuit protection devices. Maximum switching frequency varies by duty: 800 operations per hour at AC-1 (resistive), 700 at AC-3 (motor start/run), 400 at AC-2 (slip-ring motor), and 200 at AC-4 (plugging/inching). Use the AC-3e rating of 700 ops/h as the practical benchmark for standard motor starting. Mechanical life is typically 10,000,000 operations — a design-life figure that assumes proper coil suppression and within-spec switching frequency.