SIRIUS S12 contactor, AC coil 48–130 V
The Siemens 3RT1373-6AF36 is a SIRIUS-brand size S12 contactor with a 48–130 V AC coil rated for both 50 Hz and 60 Hz operation, drawing 17 VA at each frequency. The screw-type coil terminals and integrated auxiliary switch make it a direct fit for motor-starting and resistive-load switching in standard control panels. Mounting position is flexible: vertical surface with ±180° rotation, or tilted forward/backward ±30° at 0° rotation, or standing — useful when retrofitting into existing enclosures where the rail orientation is already fixed. The auxiliary contact block carries a rated current of 4 A at 230 V AC and 3 A at 400 V AC, with lower ratings at 24 V DC (3 A) and 110–125 V DC (0.55 A). These ratings define the signal-level switching capacity for interlocking, status feedback, or PLC input circuits — the 230 V AC figure is the one to size against for typical control-voltage loops.
Panel integration and wiring
Dimensions are 225 mm height, 184 mm width, 180 mm depth — the S12 frame occupies a standard footprint on the mounting surface. Fastening is by screw fixing, not DIN-rail snap-on, so plan for drilled holes or a mounting plate. The main circuit terminals accept 1x (1–4 mm²) or 2x (1–4 mm²) solid or stranded copper; the same range applies to the auxiliary terminals. Clearance requirements: 10 mm upwards, 20 mm forwards, 10 mm downwards, 10 mm at the sides — these are the minimum air gaps for heat dissipation and arc clearance, not suggestions.
Auxiliary contact ratings across the voltage range
The auxiliary switch is rated for breaking at multiple DC voltages: 3 A at 24 V, 1.5 A at 48 V, 0.55 A at 110 V and 125 V, 0.3 A at 220 V. On AC: 4 A at 230 V, 3 A at 400 V, 2 A at 500 V and 690 V. These are the maximum breaking currents — derate for inductive loads. The AC ratings at 400 V and 690 V cover the common European low-voltage distribution levels, while the 500 V rating suits some North American 480 V circuits.