This standard is a unified regulation for marking circuits with wire colors in electrical complete sets, or selecting wire colors according to circuits. GB/T 2681-1981 Wire colors in electrical complete sets GB/T2681-1981 Standard download decompression password: www.bzxz.net

1 Scope
National Standard of the People's Republic of China
Wire Colors in Complete Electrical Installations
GB 2681 81
This standard is for the unified provisions of marking circuits by wire colors in complete electrical installations, or selecting wire colors according to circuits. 2 Purpose
The purpose of this standard is to unify the meaning of the marking of various colors. And to identify circuits according to the colors of bare wires (including busbars) or insulated wires. 3 When marking circuits according to wire colors
3.1 Black: Internal wiring of devices and equipment. 3.2 Brown: Positive pole of DC circuit.
3.3 Red: Phase C of three-phase circuit;
Collector of semiconductor triode:
Cathode of semiconductor monolithic tube, rectifier diode or thyristor. 3.4 Yellow: Phase A of three-phase circuit:
Base of semiconductor triode;
Control electrode of thyristor and bidirectional thyristor. 3.5 Green: Phase B of three-phase circuit.
3.6 Blue: Negative electrode of DC circuit;
Emitter of semiconductor triode;
Anode of semiconductor diode, rectifier diode or thyristor. 3.7 Light blue: Zero line or neutral line of three-phase circuit: Ground neutral line of DC circuit.
3.8 Yellow: Main electrode of bidirectional thyristor; Semiconductor circuit without designated color.
3.9 Yellow and green (each color is about 15 to 100 mm wide and alternately pasted): Ground wire for safety. 3.10 Red and black in parallel: AC circuit connected with double-core wire or double twisted wire. 4 When selecting the wire color according to the circuit
4.1 Phase A of AC three-phase circuit: yellow, phase B: green;
Phase C: red;
Zero line or neutral line: light blue:
Safety grounding wire: yellow and green. 4.2 AC circuit connected by Xing double-core wire or double twisted wire: red and black in parallel. 1.3 Positive pole of DC circuit: brown;
Negative pole: blue;
Grounding neutral line: light blue.
National Standards
Bureau of Standardization
Proposed by the First Ministry of Machinery Industry of the People's Republic of China on July 1, 1982
Tianjin Electric Drive Design Institute
Shanghai Electric Complete Plant
GB 2681 81
4.4 Collector of semiconductor transistor in semiconductor circuit: red Base: yellow;
Emitter: blue.
Anode of semiconductor diode and rectifier: blue; cathode: red.
Anode of thyristor: blue;
control electrode: yellow,
cathode: red.
Control electrode of bidirectional thyristor: yellow; main electrode:
white.
4.5 Internal wiring of the whole device and equipment is generally recommended: black; semiconductor circuit: self-color;
When there is confusion: other colors other than the designated colors (such as: orange, purple, gray, green, rose red, etc.) are allowed. bzxZ.net
4.6 When marking the color of the body, if there are two or more markable colors on a wire, the color should be determined according to the specific situation of the circuit and the meaning that needs to be expressed in the circuit. Note: For busbars of certain products (such as marine electrical appliances), if there is an international standard specified internationally and it differs from the provisions of Articles 4.1 and 4.3, it is also allowed to be marked with the color code specified in the international standard.
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