What it is and where it lands
The Siemens SIRIUS 3RT1036-3KK84-0LA0 is a size S2 power contactor with a 52 VDC coil, screw-type terminals for the main circuit, and IP00 protection on the front and at the terminals. It's rated for 30 kW at 500 V in AC-3 duty and 22 kW at 400 V in AC-2 duty — that's the motor-switching number that decides fit for pump, fan, and compressor loads. The 52 VDC coil pulls in at the rated value and drops out below the holding threshold; arcing time runs 10 to 15 ms, DC arcing 20 to 25 ms. Mechanical life is 10 million operations typical, and the switching frequency tops out at 800 ops/h under AC-3, 1000 ops/h under AC-1. Mounts via screw and snap-on onto 35 mm DIN rail per EN 50022, and side-by-side mounting is allowed — no derating gap needed if the ambient stays within the -40 to +70 °C operating range.
Terminal and wiring detail
Main circuit terminals accept solid wire 2x (0.25 to 2.5 mm²) or stranded 2x (0.75 to 25 mm²). The auxiliary/control circuit takes solid or stranded 2x (0.75 to 16 mm²). Pollution degree 3 means it's rated for industrial environments with conductive pollution — no conformal coating required for normal panel conditions. Storage temperature range is -55 to +80 °C, so it handles warehouse extremes without issue.
Duty ratings at a glance
AC-3 motor switching: 30 kW at 500 V, 11.4 kW at 690 V. AC-2 (slip-ring motor): 22 kW at 400 V. AC-4 (plugging/inching): 41 A at 400 V. For resistive loads (AC-1), the switching frequency goes to 1000 ops/h. The coil draws 10 A at 24 V, 6 A at 230 V, 3 A at 400 V, 1 A at 110 V, 0.3 A at 220 V — these are the pick-up/hold currents, not the main contact ratings. Minimum permissible conductor cross-section at 40 °C is 16 mm².