S10 frame, spring coil terminations
The 3RT1066-2NB36: This is a SIRIUS S10-frame power contactor, the largest standard frame in the SIRIUS contactor family before you step to the 3RT107 or vacuum types. The 210 mm height, 202 mm depth, and 145 mm width mean it needs a full 3.05 dm³ of enclosure volume — plan the backpanel layout with that footprint, not just the DIN-rail clip zone. The magnet coil connects via spring-type terminals, not screw clamps — so the control wiring is a push-in job for solid or ferruled stranded conductors up to 2x 2.5 mm². The power circuit, by contrast, takes stranded cable from 70 to 240 mm², which is a lug-and-bolt connection through a single 11 mm hole. That split — spring on the coil, bolted on the power — is typical for this frame size and avoids the nuisance of loose power terminations under thermal cycling.
Coil voltage and auxiliary contact capacity
Rated control supply voltage is 21 to 27.3 V, which covers nominal 24 VDC systems with margin for brownout. If you're switching a PLC input or a small relay off this contactor's aux, stay within those limits at the applied voltage. Mechanical endurance is 10 million operations typical — that's the life of the mechanism before wear, not the electrical life under load. Electrical life depends on the duty class and switching frequency: at AC-3 (motor switching) the maximum rate is 500 operations per hour, while AC-4 (inching/plugging) drops to 130 per hour.
Mounting, clearances, and environment
Fastening is by screw fixing — four M6 or M8 bolts through the 11 mm mounting holes. Minimum clearances to adjacent metalwork: 10 mm upwards, downwards, and sideways, and 20 mm forwards. Those are the free-air spacing for arc extinction — don't crowd the contactor against the enclosure wall or another device. The 0.8 initial value and 1.1 full-scale value likely refer to the coil operating range at the voltage limits — the contactor picks at 0.8× rated voltage and drops out at 1.1×. That's standard for DC-operated contactors and means the coil won't drop out on a moderate voltage sag.