SIRIUS S0 contactor — panel fit and coil choice
The Siemens 3RT2326-1AL20-4AA0 is a SIRIUS S0 contactor with an AC-operated coil terminated at screw-type terminals. It mounts via screw or snap-on onto 35 mm DIN rail per DIN EN 60715, fitting a 45 mm wide slot in the enclosure. The S0 frame size is the mid-range compact body in the SIRIUS family — sized for motor loads and resistive switching in control panels up to around 7.5 kW at 400 V, though the exact motor rating depends on the utilization category. The AC coil is rated at 230 V at both 50 Hz and 60 Hz, drawing 0.25 A at 50 Hz and 0.28 A at 60 Hz. That means the coil inrush and hold current are modest — a standard 230 V control transformer or a PLC digital output driving an interposing relay can handle it. The operating temperature range is -25 to +60 °C, with storage from -55 to +80 °C, so it handles warm panel interiors without derating up to 60 °C ambient. The auxiliary switch is included as standard (one N/O + one N/C, typical for the S0 frame), with contact ratings spanning 24 V to 600 V AC. At 24 V it switches 10 A; at 230 V it switches 10 A; at 400 V it switches 3 A; at 600 V it switches 0.1 A. These ratings cover pilot duty and control circuit isolation across common control voltages.
Wiring and clearance
Main contacts accept solid or stranded wire from 1 to 10 mm² (roughly 16 to 8 AWG). Auxiliary contacts accept 2x (0.5 to 1.5 mm²) solid or 2x (0.75 to 2.5 mm²) stranded — typical for control wiring with ferrules. Minimum clearance to adjacent devices: 10 mm upwards, 10 mm forwards, 10 mm downwards, and 6 mm to the side. That is tight enough for dense DIN-rail layouts but leaves room for finger-safe wiring ducts. Mounting position is flexible: +/-180° rotation on a vertical surface, and can be tilted forward/backward by +/-22.5° on a vertical surface. That helps when the contactor sits in a swing-frame panel or a slanted enclosure.