Electrical wiring is indispensable in our daily lives, but how many people actually know about it? Not only do electrical wiring come in many different sizes and types, but electrical boxes often have different colors of wire, and each color represents a different type of wire.
About Wire Colors
Generally speaking, electrical wiring colors are composed of three colors: yellow, green, and red. Phase A is yellow, phase B is green, and phase C is red, representing the busbars.
Yellow: Phase L1 (phase A) in a three-phase circuit
Green: Phase L2 (phase B) in a three-phase circuit
Red: Phase L3 (phase C) in a three-phase circuit
Blue: Working Neutral (N)
Yellow-green: Protective Neutral (PE)
Different Wire Colors Represent Different Wires
1. Signal Cable: This is typically a flame-retardant/fire-resistant twisted-pair red-and-blue flexible cable (red positive, blue negative). Smoke detectors, heat detectors, manual alarm buttons, and other signal modules are connected to the signal cable. Components like water flow indicators, alarm valves, fire dampers, and quick-release valves are connected to the signal cable through signal modules and then to the alarm control panel.
2. Power Cord: Typically, it should be flame-retardant/fire-resistant red-and-black twisted-pair flexible cable or flame-retardant BV rigid cable (red positive, black negative). The control module requires both signal and power cables. Alarm bells with addresses should be connected directly to the signal and power cables. Alarm bells without addresses should be connected to the signal and power cables via the control output module. For example, air supply valves, smoke exhaust valves, electric valves, electric smoke exhaust vents, blowers, air supply fans, smoke exhaust fans, air compressor controls, and forced disconnection of non-fire power supplies, as well as elevators, should be connected to the alarm control panel via the control module, signal cables, and power cables.
3. Hard-wired cables: Some equipment, such as fire pumps, sprinkler pumps, air supply fans, and smoke exhaust fans, requires direct control from the fire control room via a multi-wire manual control panel. Depending on the equipment manufacturer, these cables are typically 6/4 core sheathed cables or 6/4 flame-retardant BV hard-wired cables. BV hard-wired cables are typically color-coded to distinguish them.
4. Broadcast cables: Flame-retardant/fire-resistant red and black twisted-pair cables (red for positive and black for negative) are typically used to connect the fire broadcast host and the speakers in the fire control room.
5. Telephone cables: White flame-retardant parallel cables are typically used to connect the fire control room telephone host to the fire telephone and telephone jacks.
I'd also like to share some additional information on wire colors.
1) Who specifies the wire colors?
National Standard GB50258-96 stipulates that when wiring uses multi-phase conductors, the colors of the phase conductors should be easily distinguishable, and the phase conductors and neutral conductor (i.e., the working neutral conductor, N) should be different colors. The protective earth (PE) wire should use alternating yellow and green insulation; the neutral (N) wire should use light blue insulation. GB/T6995.2-2008 specifies that the three-phase cables (L1, L2, and L3) should be yellow, green, and red.
2) Why is it important to distinguish wire colors?
The national standard requires different cable colors for different cables. This is primarily to ensure that the phase, neutral, and protective earth wires are correctly distinguished, preventing operational errors. While common power construction companies have strict operating procedures, carelessness or misoperation can lead to wiring errors in real-world construction, resulting in serious electrical accidents.
The above is a brief discussion from Jinhuanyu Wire and Cable: Do you know how many colors of wire there are? I hope it will be helpful.
After reading this information on distinguishing wire colors, you'll have a deeper understanding of wires. In reality, the wiring connections we encounter most often at home are probably those we connect ourselves. Many people also make their own connections at home, which is where the above knowledge comes in handy. I hope this information is helpful.
