What It Is and What It Does
The 3RT2027-1KB40: The contactor carries no built-in auxiliary switch, so any auxiliary contact blocks needed for status feedback or interlocking must be added externally. The coil termination uses screw-type terminals, which is the standard for this frame size. Mounting is via screw and snap-on onto 35 mm DIN rail per DIN EN 60715, with a width of 45 mm and a depth of 107 mm. The mounting position allows +/-180° rotation on a vertical surface and can be tilted forward/backward by +/-22.5°.
Key Ratings and What They Mean for Your Application
The 24 VDC coil is the controlling voltage — this contactor pulls in and seals at that nominal level. The operating temperature range is -25 to +60 °C during operation, with storage from -55 to +80 °C, so it handles typical panel ambient conditions without derating concerns. Switching frequency depends on the duty class: at AC-1 (resistive loads) the maximum is 1,000 operations per hour; at AC-3 (standard motor starting) it is 750 ops/h; at AC-4 (plugging/inching) it drops to 250 ops/h. These limits govern the contactor's thermal endurance — exceeding them shortens life. The contactor's mechanical life is rated at 10,000,000 operations typical, which is the expected wear-out figure for the mechanism itself under proper coil voltage and within the switching frequency limits.
Wiring and Integration Notes
Main contact wiring accepts solid or stranded conductors from 1 to 10 mm². For auxiliary circuits, the terminal capacity is 2x (0.5 to 1.5 mm²) or 2x (0.75 to 2.5 mm²). The main contact tightening torque range is 16 to 8 Nm (the evidence lists the range in descending order — verify the exact value on the nameplate). Clearance distances: 10 mm upwards, 10 mm forwards, 10 mm downwards, and 6 mm at the side. These are the minimum air gaps required around the contactor for heat dissipation and arc containment. The arcing time is specified at 10 to 10 ms — a tight window that suggests consistent arc extinction behavior across the rated current range.
Sourcing and Lifecycle Reality
The 3RT2027-1KB40 is a 24 VDC variant. If your panel was specified around a different coil voltage (e.g., 24 VAC or 230 VAC), verify coil compatibility before substituting — the mechanical footprint is shared across the S0 frame, but the coil voltage must match the control circuit.