Vacuum contactor for high-cycle motor switching
The Siemens 3RT1266-6NP36 is a SIRIUS vacuum contactor in Size S10, designed for applications where arc extinction and contact life are critical — vacuum bottles quench the arc in a sealed chamber, so the main contacts see minimal erosion even under frequent AC-3 or AC-4 duty.
Mounting and clearance for panel integration
Fastening is by screw fixing through a single 11 mm hole — the contactor is bolted, not DIN-rail snapped, so the panel backplate needs a drilled and tapped location. Dimensions are 210 mm high × 145 mm wide × 206 mm deep — the depth is the dominant constraint for enclosure selection; a standard 300 mm deep cabinet leaves about 94 mm for wiring and arc chute clearance behind the door.
Switching performance and auxiliary contact ratings
Mechanical endurance is 10 million operating cycles typical — the vacuum interrupter contributes to this by eliminating contact erosion from arcing in air, so the contactor outlasts an equivalent air-break unit in high-cycle applications like conveyor or pump cycling. Maximum switching rates: 750 operations per hour in AC-1 and AC-3 duty, 250 ops/h in AC-2 and AC-4 — AC-4 (plugging/inching) is the most severe; the 250 ops/h limit reflects the thermal recovery time of the vacuum bottle after a high-energy break.
Power cable termination and ambient limits
Main power conductors: stranded 70–240 mm² — this is a heavy cable range, consistent with a Size S10 contactor rated for motor currents up to roughly 400–500 A in AC-3; the lug or crimp terminal must match the contactor's bus bar hole pattern. Coil power factor at 50/60 Hz is 0.4 — this is the phase angle between voltage and current in the AC coil circuit; a control transformer feeding multiple such contactors must be sized for the apparent power (VA), not just the real power (W), to avoid saturation on inrush.