What are the various colors in the wire and cable?

- Oct 22, 2019-

1, According to the wire color marking circuit

Black - internal wiring of devices and equipment.


Brown - the positive pole of the DC circuit.


Red - phase C of a three-phase circuit; collector of a semiconductor transistor; cathode of a semiconductor diode, rectifier diode or thyristor.


Yellow - phase A of a three-phase circuit; base of a semiconductor transistor; control pole of a thyristor and a triac.


Green - Phase B of a three-phase circuit.


Blue - the negative pole of the DC circuit; the emitter of the semiconductor transistor; the anode of a semiconductor diode, a rectifier diode or a thyristor.


Light blue - the neutral or neutral of a three-phase circuit; the grounded neutral of a DC circuit.


White - the main electrode of the bidirectional thyristor; no semiconductor circuit of the specified color.


Yellow and green two colors (each color is about 15 to 100 mm alternately attached) - a safe grounding wire.


Red and black parallel—AC circuits connected by twin-core or double stranded wires.


2. When selecting the color of the wire according to the circuit


AC three-phase circuit

Phase A: yellow; Phase B: Green; Phase C: Red;

Neutral or neutral: Light blue; Safety ground wire: yellow and green.


AC circuit connected by double-core wire or double stranded wire

Red and black are parallel.


DC circuit

Positive: brown; negative: blue; grounded neutral: light blue.


Semiconductor circuit

Collector of semiconductor transistor: red; base: yellow; emitter: blue. Anodes of semiconductor diodes and rectifier diodes: blue; cathode: red.

Anode of thyristor tube: blue; control electrode: yellow; cathode: red.


Semiconductor circuit color

Control electrode of the two-way thyristor: yellow; main electrode: white.

Internal wiring of the entire device and equipment is generally recommended: black; semiconductor circuit: white;

When there is confusion: allow the selection of other colors outside the color (such as: orange, purple, gray, green blue, rose, etc.).


Specific color

On a wire, if there are two or more kinds of calibratable colors, depending on the specific conditions of the circuit, the color is fixed according to a certain meaning that needs to be expressed in the circuit.

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