The Siemens 3RT1034-3BB40-ZN88X95 is a SIRIUS S2-frame power contactor rated for 18.5 kW at 500 V AC-3, with a 24 VDC coil. The IP20 front and IP00 terminal area mean it's safe for finger contact on the face but the wiring zone expects enclosure protection.
The AC-3 motor rating of 18.5 kW at 500 V tells you this contactor handles a standard 25 hp induction motor on a 480 V line. At 400 V AC-4 it's rated 29 A — that's the reversing or plugging duty cycle, so if your application jogs or brakes the load frequently, this is the number that governs contact life, not the AC-3 figure. Coil pickup at 24 VDC draws 10 A inrush (at rated value), holding at 0.8 A initial. Dropout time is 20 to 30 ms, arcing time 10 to 15 ms — that's fast enough for most safety circuits but verify your PLC cycle time if you're sequencing multiple contactors. Terminals accept solid 2x (0.25 to 2.5 mm²) or stranded 2x (0.75 to 25 mm²) on the main circuit — screw-type, so you'll need a torque driver for the larger lugs. The 55 mm width and 112 mm height leave room for auxiliary contact blocks alongside.