The 70 mm height keeps it below typical busbar or trunking runs mounted at 150 mm pitch. These are the minimum air gaps to adjacent metalwork or other devices. A panel builder stacking contactors side-by-side on the rail needs to leave that 6 mm side gap for arc containment and heat dissipation.
Switching duty and lifecycle
The contactor is rated for different switching frequencies depending on the load category: up to 1,000 operations per hour for AC-1 resistive loads, 750 ops/h for AC-2 and AC-3 motor starting, and 250 ops/h for AC-4 plugging or inching duty. The AC-3e maximum matches the AC-3 figure at 750 ops/h. The typical mechanical life of the contactor is 30 million operations, which covers years of cycling in a conveyor or pump application. The arcing time on the main contacts runs 10 to 15 ms at AC, with a spread of 4 to 15 ms depending on the point in the current waveform where the contacts part.