What are the wires and cables for home installation?

In home decoration, there are two kinds of wires commonly used. One is called single-strand wire, also called hard wire, and the other is called multi-strand wire, also called flexible wire.    1. Hard wire: professionally called BV wire, mainly used for power supply, lighting, socket, air conditioning, and cable and wire for power devices, household appliances, instruments and telecommunication equipment with AC voltage of 450/750V and below. The hard wire has a certain hardness, and it will be more convenient in bending and straightening.    2. Flexible wire: professionally called BVR wire, suitable for cables and wires used for power devices, household appliances, instruments and telecommunication equipment with AC voltage of 450/750V and below, such as distribution box. The production of flexible wire is more complicated than that of hard wire, and the current carrying capacity of high frequency circuit flexible wire is larger than that of hard wire.    3. Home decoration wires are divided into BV, BVR, RV, BVVB and RVV, with the following differences: BV, BVR, RV: all single-core wires. BV: It is a single core wire of copper wire. It is hard, also called hard wire. BVR: It consists of multiple copper wires, also known as flexible wires, twisted into a conductor. RV: It is also a flexible wire. It is a single-core wire with more strands of copper wires twisted together. It is generally not used for home decoration.    4. Recommended for home decoration: BV or BVR. BVVB: It is hard sheathed wire, that is, two or three BV wires are sheathed together. RVV: It is a soft sheath wire, that is, two three or four RV wires are sheathed together. BVVB sheathed wire is recommended for general decoration. In addition, the electrical wires for home decoration shall not be damaged inside the wall and outside the wall as much as possible; There is no damage in the line and no damage at the end of the line to ensure safety.

How to choose and buy home wiring?

Strong current wire is an indispensable basic building material in home decoration, and also an important part of concealed works. Whether the quality of the wire is qualified or not is directly related to the decoration effect and electricity safety. Therefore, how to choose and buy home wiring?    1. Packaging and inspection report.  Look at the inspection report. As a product that affects personal and property safety, wires and cables have always been listed as the focus of government supervision and inspection, and regular manufacturers are subject to periodic inspection by the supervision department. Therefore, the seller should be able to provide the inspection report of the quality inspection department, otherwise, there is no basis for the quality of the product.  Good drum packaging can reduce the wear of insulation layer during production, transportation and handling, and facilitate electrician installation. There shall be a complete certificate of conformity in the package, which shall include complete information such as specification, execution scale, rated voltage, length, date, name and address of the factory.    2. Wire packaging identification.  Check the "CCC" certification mark. Therefore, wire and cable products are subject to the national compulsory safety certification. All manufacturers must obtain the "CCC" certification certified by the China National Electrotechnical Product Certification Commission, obtain the "CCC" certification mark, and have the "CCC" certification mark on the certificate or product.    Whether there is "CCC" and production license number for China's compulsory product certification; Check whether there is quality system certification; Check whether the certificate is standard; Check whether the factory name, address, maintenance seal and production date are available; Check whether the wire is printed with trademark, specification, voltage, etc. It also depends on the cross section of the copper core of the wire. The superior red copper is bright and soft in color, and the copper core is red in yellow, indicating that the copper used is of good quality, while the white in yellow is a reflection of the low quality copper.    The packaging of wire and cable products is the same as that of other products. All large and medium-sized formal enterprises that produce products that meet the requirements of national standards pay great attention to the packaging of wire and cable products. Pay attention to the exquisite packaging, clear printing and complete model, specification, factory name and address when purchasing.    3. Look at the appearance.  The appearance of the product is smooth and round, and the color is uniform. For wire and cable enterprises whose products meet the requirements of national standards, in order to improve the product quality and ensure that the products meet the requirements of national standards, they strictly control the purchase of raw materials, production equipment, production technology and other aspects. Therefore, the appearance of the wire and cable products produced meet the standard requirements: smooth, round, uniform color. The appearance of fake and inferior products is rough and matt. For rubber insulated flexible cables, the appearance is required to be round, and the sheath, insulation and conductor are tight and not easy to peel. The fake and inferior products have rough appearance, large ovality and low insulation strength of the sheath, which can be removed by hand.    4. Check wire size.  It is important to see whether the length and wire core thickness have limbs. According to the relevant standards, the error of wire length cannot exceed 2% and the diameter of section wire cannot exceed 0.02%. However, there are a lot of phenomena in the market that the length is short and the section is fraudulent (for example, the line with a section of 2.5 mm2 is only 2 mm2 thick).    5. Look at the color of copper.  The copper core of qualified copper wire should be purplish red, shiny and soft. The fake copper core wire copper core is purple black, yellow or white.    When the color conflicts with the thickness, the color is preferred, for example, between the thinner red copper and the thicker brass, the red copper is preferred.  At the same time, the thicker the wire, the stronger the conductivity - when comparing the thickness, only the conductor should be compared, and the thickness of the insulation layer should not be added.  The conductor is glossy, and the DC resistance and conductor structure size meet the requirements of national standards. Wire and cable products that meet the requirements of national standards, whether aluminum or copper conductors, are relatively bright and free of oil, so the DC resistance of conductors fully meet the national standards, with good conductivity and high safety.    6. Look at the insulating rubber.  The insulation layer of fake and inferior wires seems to be very thick, but in fact, most of them are made of recycled plastic. As long as they are squeezed slightly, the extruded part will become white and powder will fall off. 3. Weight of wire. The wires with good quality are generally within the specified weight range. For example, the common plastic insulated single-stranded copper core wire with a cross-sectional area of 1.5mm2 weighs 1.8-1.9kg per 100m.    7. View manufacturing process.  Cut a section of insulation layer to see if its core is in the middle of the insulation layer. What is not in the middle is the core deviation caused by the low technology. If the power is small, it can calm people down. Once the power is large, the thinner side is likely to be broken down by the current. The insulation layer of regular wires shall be uniform in thickness, without core deviation, and shall be tightly wrapped on the conductor. It should be noted that some inferior insulation layers use recycled plastic. As long as you press it a little hard, the extruded part will become white and powder will fall.    8. Field test.  A wire head can be repeatedly bent by hand. Those with soft hand feel, good fatigue resistance, large plastic or rubber hand feel elasticity and no cracks on the wire insulator are excellent products. The plastic skin on the outer layer of the wire should be bright and fine, and there should be no open flame when ignited with a lighter.  In addition, the purchase of wires and cables should also consider its use. Generally, the wire current is calculated according to the size of the electrical power, and then the wire specification is selected according to the size of the current.

Identification method of wire quality

1. Looking at the label printing sample carefully, the handwriting is blurred and the address is unknown. It refers to looking at the printed words on the label and insulation skin. If there are wrong words or the printing depth is different or the words are fuzzy, please pay attention.    2. Twist and rub the insulating skin by hand, resulting in color fading and poor quality. It refers to rubbing the insulation skin with your fingers. The skin of some inferior insulation wires is easy to fade, especially the red wire. After rubbing, the color of the skin left on the fingers or the words printed on the skin are usually wiped off.    3. Then use your nails to cut and pinch the line, and then cut and peel off the line. It refers to scratching and pinching the insulation skin with a nail. Generally, it is inferior wire that can be scratched and pinched off.    4. Repeatedly bend the insulation wire, and it will break three to four times. It refers to repeatedly bending the insulated wire. The insulation layer of the inferior wire is generally of poor quality. The insulation layer will break after 3~4 times of bending.    5. Insulate the ignition wire with fire and ignite spontaneously when leaving the open fire wire. It refers to the inferior wire that ignites the insulating layer and can spontaneously ignite after leaving the open fire.    6. The wire core is usually made of aluminum and copper, and the color becomes dark and light. It refers to the color of wire core. The color of inferior wire is gray and has no metallic luster.    7. Measure the inner diameter and outer diameter carefully, and see the pine when weighing. It means that if it cannot be determined by the above six methods, the outer diameter and core diameter of the insulated wire can also be measured, and the allowable error is ± 10%. If the measured value exceeds the allowable error, it is basically a poor quality insulated wire.