(Red, yellow, blue), zero line-N (blue or black), ground-E (yellow-green)
sequence is left and right, that is, the left side of the zero line, the right side of the line of fire.
Single-phase three-wire socket, the middle of the ground wire, but also for positioning, the other ends were connected to the line and the zero line, the wiring
The other end connected with the user's ground contact, from the role of ground protection. The ground wire is a good way to prevent the electric shock accident by connecting the equipment or the electrical connection of the appliance to the earth.
in the user area to use three-phase five-wire power supply, the fifth line is the grounding protection line (ground), one end is near the user area with metal conductors buried in the ground
