CKJ3-800/1000/1250/1140 AC low-voltage vacuum contactor is used in AC 50Hz, main circuit rated working voltage to 3KV, rated working current to 300A current system, for long-distance connection and breaking circuit and frequent Ground start and control for AC motors. It is also suitable for forming a magnetic starter with various protection devices, and has the characteristics that the arc is not exposed. Especially suitable for forming explosion-proof magnetic starters. Suitable for industries such as coal or oil