The meaning and standard of cable color

Everyone knows that the wires in the cable have different colors. What are these colors used for? What does the color on the cable mean?

Regulations for cable skin color
National standard: yellow, green, red. Blue stands for A. B. C. N

When marking the circuit according to the wire color

1. Black: internal wiring of devices and equipment.
2. Brown: the positive pole of the DC circuit.
3. Red: three-phase circuit and C-phase;

The collector of a semiconductor transistor;
The cathode of a semiconductor diode, rectifier diode, or thyristor.
4. Yellow: Phase A of the three-phase circuit;

The base of a semiconductor transistor;
Control electrode of thyristor and triac.
5. Green: Phase B of the three-phase circuit.
6. Blue: the negative pole of the DC circuit;

The emitter of a semiconductor transistor;
The anode of a semiconductor diode, rectifier diode, or thyristor.
7. Light blue: the zero or neutral line of the three-phase circuit;

The grounded neutral of the DC circuit.
8. White: the main electrode of the triac;
Semiconductor circuits without designated colors.
9. Yellow and green two colors (each color is about 15~100mm in width alternately attached); safety grounding wire.
10. Red and black parallel: AC circuits connected by double-core wires or twisted-pair wires.

When selecting the wire color according to the circuit

1. AC three-phase circuit
Phase A: yellow;
Phase B: Green;
Phase C: red;
Zero line or neutral line, light blue;
Safety grounding wire: yellow and green double colors.

2. AC circuit connected by double-core wires or twisted-pair wires: red and black parallel.

3. DC circuit
Positive electrode: brown;
Negative electrode: blue;
Grounding neutral line: light blue.

4. The semiconductor triode of the semiconductor circuit
Collector: red;
Base: yellow;
Emitter: blue.
Semiconductor diodes and rectifier diodes
Anode: blue;
Cathode: red.
Thyristor
Anode: blue;
Control pole: yellow;
Cathode: red.
Triac
Control pole: yellow;
Main electrode: white.

5. The internal wiring of the entire device and equipment is generally recommended: black;
Semiconductor circuit: white;
When there is confusion: other colors (such as orange, purple, gray, green blue, rose red, etc.) other than the specified colors are allowed.

6. In the specific color marking, if there are two or more colors that can be marked on a wire, the color shall be fixed according to a certain meaning that needs to be expressed in the circuit, depending on the specific situation of the circuit.