What it is and where it lands
The Siemens 3RT1054-3AS36 is a SIRIUS S6 power contactor — screw-fixed, Size S6 frame, with a 500-550 V AC coil and spring-type coil terminals. It carries an auxiliary switch on board, so you don't need a separate side-mount block for basic status feedback. This is the frame size you spec for motor loads in the 75-90 kW range on 400 V three-phase, typical for pumps, fans, and conveyors in MCC or panel builds. Mounting position is flexible: vertical surface with ±90° rotation and ±22.5° tilt forward/back. That covers most panel layouts without a special bracket. Fastening is screw fixing — no DIN-rail clip on this frame, so plan for drilled backplate or mounting channel.
Duty ratings and what they mean for your load
Switching frequency varies by duty class: 1 000 cycles/hour in AC-3 (standard squirrel-cage motor start/run), 800 in AC-1 (resistive loads), 400 in AC-2 (slip-ring motors), and 130 in AC-4 (plugging/inching). The AC-3e rating also sits at 1 000 cycles/hour. These are the numbers that govern contactor life on a real line — if your application cycles faster than the AC-3 ceiling, you need to step up a frame or reduce the load current. Auxiliary contact ratings span the control-voltage range you'll encounter: 10 A at 24 V, 2 A at 48 V and 60 V, 1 A at 110 V, 0.9 A at 125 V, and 0.3 A at 220 V. These are the make/break capacities for the pilot-duty side — relay coils, PLC inputs, indicator lamps. The 10 A at 24 V gives you headroom for a multi-coil interposing bank.
Environmental and wiring
Operating temperature range is -25 to +60 °C; storage range is -55 to +80 °C. That covers most indoor panel environments and unheated warehouses. The storage limit is the handling limit — the contactor can sit on the shelf in a cold store without damage. Power terminals accept stranded wire from 16 to 70 mm² — that's the range for the motor and line connections on an S6 frame. Coil terminals are spring-type, accepting solid or stranded 2x (0.25 to 2.5 mm²). Keep the coil wiring to 1.5 mm² ferruled for reliable spring retention.