The 230 V AC coil pulls in the main poles; the built-in 1 NC auxiliary contact provides electrical interlocking to prevent both contactors from closing simultaneously.
AC-1 rating covers resistive loads at the same current; The 3 NO power poles switch the motor lines; the 1 NC auxiliary is wired into the coil circuit of the opposite contactor to enforce mechanical and electrical interlock.
Vibration resistance of 4 Gn closed and 2 Gn open (5–300 Hz) means it holds in on a typical industrial panel wall without nuisance dropout. Shock ratings of 10–15 Gn on the Y and Z axes closed, 6–10 Gn open, cover most machine-mounted installations.