These contactors can maintain the closed position with the control curcuit deenergized. They are particularly useful in cases when accidental opening may cause disfunctioning to the system and where applications require to minimize the dissipated energy caused by long period of closing and it is automatically kept in such a position with deenergized coil. The latch function is mechanical or magnetic and eletrical supply is only required during pick-up operating time. The contactor opens only when the trypping coil is energized. The use of the mechanical and magnetic latch has the following advantages. -Total elimination of coil overheating or burning even in case of long overvoltages periods - Significant energy saving - Unaffected by voltage drops