Vacuum contactor for high-cycle motor switching
The Siemens 3RT1266-6AM36 is a SIRIUS vacuum contactor in frame size S10, designed for motor switching where arc extinction needs to be fast and contact erosion minimal — vacuum interrupters handle the arc in a sealed chamber, so the contactor delivers consistent switching performance over its mechanical life of 10 million operations typical. Rated for AC-3 duty at 750 operating cycles per hour, it suits conveyor, pump, and compressor starts where the load is switched under full current each cycle.
Power terminals accept stranded cable from 70 to 240 mm² — that covers the full range for a contactor this size, from a 95 mm² feed down to a 185 mm² motor cable without reducers.
Duty-cycle and thermal limits
Switching frequency varies by duty: 750 ops/h for AC-1 (resistive) and AC-3 (motor start/run), dropping to 250 ops/h for AC-2 (slip-ring motor) and AC-4 (plugging/inching) — if the application includes frequent reversing or jogging, the 250 ops/h ceiling governs the cycle budget.