What it is and what it does
The Siemens 3RT1036-1AN24 is a SIRIUS S2-size power contactor, rated for 22 kW at 400 V in AC-2 duty — that's the standard rating for slip-ring motor starting and reversing, where the contactor makes and breaks the load under current. It also carries a 30 kW rating at 500 V and 11.4 kW at 690 V, so it's not locked to one voltage class. The coil is 220 V at 50/60 Hz, with an operating range of 0.8 to 1.1 times rated voltage at 50 Hz and 0.85 to 1.1 at 60 Hz, meaning it holds in through brownout conditions down to about 176 V. This is a screw-type terminal contactor — no spring-cage option here — so it's a straight swap for older panels where the wireman prefers a screwdriver over a push-in tool. The main circuit accepts stranded up to 25 mm² and solid up to 4 mm², with dual-wire capability on the smaller gauges. Auxiliary contacts are rated 10 A at 24 V, 6 A at 230 V, and 3 A at 400 V, which covers most PLC output and relay interposing loads without an extra interface relay.
Mounting and integration
Snaps onto 35 mm DIN rail per EN 50022, or screws directly to a backplate. At 55 mm wide and 112 mm tall, it fits a standard 6-module-wide slot in a distribution panel. The 164 mm depth leaves room for wiring ducts and finger-safe shrouds. Side-by-side mounting is allowed with no derating gap, so you can pack a row of these in a motor control centre without losing panel density. Pollution degree 3 means it's rated for the conductive dust and humidity you find in industrial enclosures — not just clean control rooms.
Environmental and mechanical limits
Operates from -25 to +60 °C and stores from -55 to +80 °C, so it handles unheated plant floors and hot summer shutdowns. Mechanical endurance is 10 million operations typical, and the maximum switching rate at AC-3 duty is 800 cycles per hour — that's about one every 4.5 seconds, which is fast enough for most conveyor jogging or pump cycling. The front face is IP20 (finger-safe), the terminals are IP00 (no protection), so it needs an enclosure or shrouding in a live panel.