General provisions, three-phase color is yellow, green, red, A, B, C three-phase respectively, and the blue is zero line, yellow, green and white for the grounding wire, wire connection with yellow, green, red, blue to zero, yellow and green line of receiving PE confirmed on A convenient or in receiving equipment shell (shell is connected to the network).
　　Sometimes the four line colors are not obvious, the three sections are the same as the wire, and the section is slightly smaller.
　　The transformer you are talking about may be the source of the control circuit, so 380V, and receive any two wires;
　　So 220V, then you take a fire line, a zero line.
　　Red is a wire, blue is zero, yellow or yellow is ground.
　　Sometimes the four line colors are not obvious, the three sections are the same as the wire, and the section is slightly smaller.
　　The transformer you are talking about may be the power source of the control circuit, so 380V.
　　So 220V, then you take a fire line, a zero line.
　　Tips for three-phase colors:
　　A yellow spring just arrived, the grass is still yellow
　　B green and then the grass will turn green
　　C red and then the common plant will flower, and when it comes to flowers, it usually comes to mind
　　Control cables will have many kinds of color, main is to make sure not to mix between each line is ok, will also have many colors in your communications cable according to cable, increasing number of different color is orange, green, brown, grey black Huang Zigong Hester prynne