The present invention relates to a power connector for receiving an electric plug. The power connector is provided with a three-piece safety shutter architecture to prevent unwanted or improper insertion of a single plug pole into the power receptacles. In this architecture, the locking bar is formed with a first and a second tabs. The first and second tabs work with a protrusion formed therebetween to engage with the safety shutters and keep the safety shutters spaced apart from each other by a predetermined distance, so that the safety shutters are slidably latched in parallel by the locking bar and only allowed to travel dependently of each other along the travel direction, making the invention to meet the strict international safety standards for household plugs, adapters and socket-outlets.