What it is and what it switches
The Siemens 3RT1036-1AP04-ZX95 is a SIRIUS power contactor in the S2 frame size, designed to switch motor loads under AC-2 duty — slip-ring motors, wound-rotor applications, or any load where the contactor makes and breaks at reduced current but carries full current continuously. Rated 22 kW at 400 V in AC-2, with an AC-4 breaking current of 41 A at 400 V for plugging or inching duty.
Mounting and wiring
Snap-on mounting onto 35 mm DIN rail per EN 50022, or screw-fixed. Screw-type terminals on the main circuit accept solid conductors up to 2x 4 mm² or stranded up to 2x 25 mm² — the stranded range covers the full S2 current capability without needing lug adapters. Side-by-side mounting allowed, so multiple contactors pack tight in a row.
What the ratings mean for your panel
Mechanical life is 10 million operations typical — that's the contactor body, not the contacts under load. The actual electrical endurance depends on the duty cycle: AC-1 (resistive) allows 1,000 operations per hour, AC-3 (standard motor start) allows 800/h, AC-4 (plugging/inching) drops to 300/h. The arcing time of 10-15 ms and AC operating time of 7-20 ms are the window you need for coordination with upstream short-circuit protection — the contactor clears fast enough to let a motor circuit protector or fuse do its job without welding the main contacts.