Ratings and what they mean for the panel
The 3RT2045-1AP04-3MA0: AC-3 switching frequency maxes at 1 000 operations per hour; AC-4 drops to 300/h — that's the plugging/inching duty cycle limit, so for high-cycle reversing applications you need to stay under 300 ops/h or derate. AC-1 resistive load allows 900 ops/h. The main contacts are rated for 10 million mechanical operations typical, so this contactor outlasts most machines it's wired into. Arcing time sits at 10 to 20 ms, with a 50 Hz arcing factor of 0.38 — that's the time the arc extinguishes per half-cycle, relevant for coordination with upstream fuses or MCCBs.
Wiring and clearance
Main power terminals accept solid wire 2.5 to 16 mm² or stranded 6 to 70 mm² — that covers most motor feeds up to 77 A. Auxiliary terminals take 2x (0.5 to 1.5 mm²) solid or stranded, or 2x (0.75 to 2.5 mm²). Minimum clearance: 10 mm upwards, 10 mm downwards, 10 mm at the side, 20 mm forwards — a standard 70 mm wide by 140 mm tall by 195 mm deep footprint. Operating temperature range -25 to +60 °C; storage -55 to +80 °C.