S10 vacuum contactor — what the frame size tells you
The 3RT1266-6AR36 is a SIRIUS vacuum contactor in frame size S10, meaning the main poles are rated for the heaviest motor switching within the S10 envelope — the vacuum bottle extinguishes the arc in a sealed chamber, so contact erosion is minimal and the mechanical life hits 10,000,000 typical operations.
Coil supply and auxiliary switching
The magnet coil accepts 440–480 V AC (rated value) and terminates at screw-type terminals — the control circuit wiring lands on the same terminal type as the main power lugs, so the wireman carries one screwdriver for the whole panel.
Power wiring — conductor range and termination
Main power conductors accept stranded cable from 70 mm² up to 240 mm² — that covers most motor feeds up to the S10 current rating without needing a reducer or splice block.
Operating frequency and thermal limits
Maximum switching rates: 750 operations/hour in AC-1 and AC-3 duty, 250 ops/hour in AC-2 and AC-4 — the vacuum bottle handles the arc, but the coil and mechanism still need the cool-down dwell between cycles.