What specifications should be used for household wires?

Home wiring is an indispensable part of our life, and the quality of pvc wire selection will be directly related to home safety. Home safety is your own safety, so you must compare more when you buy, choose the wire with guaranteed quality. So what specifications should the general home wiring choose? What about the BVR copper wire for home decoration? Now I will make a simple analysis for you.


General home decoration line specifications

The power cord for home decoration generally adopts BV2 × 2.5 and bvv2 × 1.5 model of BVV line, BVV line is the national standard code, copper sheath line bvv2 × 2.5 and bvv2 × 1.5 represents 2-core 2.5 square mm and 2-core 1.5 square mm respectively. In general, bvv2 × 2.5 main line, bvv2 × 1.5 make single electrical branch line, switch line, share bvv2 for air conditioning special line × 4 model, with special ground wire.
We all know that BVV wires are commonly used in household wires, and there is another kind of BVR wires. How much do you know about BVR wires?

BVR copper core flexible wire for home decoration

BVR wire is a kind of special soft wire for distribution cabinet, also called secondary wire. The full name is PVC insulated non sheathed wire and cable, the model specification and rated voltage are BVR 450 / 750V 2.5-95, and the production execution standard is JB / T 8734.2-2012.
The copper core PVC insulated flexible wire is used in the occasions where the fixed wiring requires softness, and the conductor temperature is 70 ℃ in normal use.
The number of bvr6 square wires, wire diameter of 19 / 0.64mm and outer diameter of 5.2mm. The conductor material of the product is made of 99.99% oxygen free copper. The copper wire has bright appearance and low resistivity, which improves its conductivity.


The only difference between BVR wire and bv wire is that the conductor diameter of R wire is soft copper wire. That is: increase the number of conductors, reduce the diameter of a single conductor, the diameter of a single conductor is less than 1 mm. In this way, the BVR wire is very soft, the laying angle requirements are greatly reduced compared with BV wire, and it is more convenient and fast when threading the conduit and trunking, which reduces the work intensity and greatly improves the work efficiency. Very popular with the majority of electrical and architectural decoration personnel welcome!
BVR wire can be divided into flame retardant wire, fire-resistant wire and low smoke halogen-free wire according to different materials, which can be flexibly controlled by users. Low smoke and halogen-free produce a very small amount of smoke in the case of flame combustion, the released gas does not contain low halogen elements, non-toxic. In case of fire, it can greatly reduce the harm to instruments, equipment and human body.
It is not difficult to see that BVR wire has many advantages, but it does not absolutely match the needs of any place. Or have to combine their own needs to buy, of course, good brand is also the key! So I hope the above can bring some help to the friends who are facing the problem of choosing household wires.

From January to March, China’s optical cable output increased by 25.2% year on year

The National Bureau of statistics released the output and growth rate of China’s major industrial products from January to March. Among the 100 major industrial products listed, except for fax machines, only 4 products showed a year-on-year decrease in output from January to March 2020. Among them, the cumulative output of abc cables was 63.996 million core kilometers, a year-on-year increase of 25.2%.


The cumulative output of pig iron was 220.971 million tons, up 8% year on year; The cumulative output of crude steel was 271042000 tons, with a year-on-year increase of 15.6%; The cumulative output of steel products was 329.401 million tons, a year-on-year increase of 22.5%; The cumulative output of ferroalloy was 9.021 million tons, a year-on-year increase of 4.7%; The cumulative output of alumina was 19.23 million tons, a year-on-year increase of 13.7%; The cumulative output of refined copper (electrolytic copper) was 2.487 million tons, with a year-on-year increase of 15.2%; The cumulative output of primary aluminum (electrolytic aluminum) was 9.758 million tons, up 8.8% year on year; The cumulative output of aluminum alloy was 2.266 million tons, with a year-on-year increase of 38.6%; The cumulative output of copper products was 4.516 million tons, a year-on-year increase of 14.8%; The cumulative output of aluminum products was 13.887 million tons, a year-on-year increase of 31.1%.
The cumulative output of generating units (generating equipment) was 31.319 million KW, up 55.5% year on year; The cumulative output of optical fiber cables was 63.996 million core kilometers, with a year-on-year increase of 25.2%; The cumulative output of lithium-ion batteries was 4790.314 million, with a year-on-year increase of 83.4%; The cumulative output of solar cells (photovoltaic cells) was 46.602 million kilowatts, up 78.2% year on year.
In March, among the 100 major industrial products listed, except for fax machines, only 8 products showed a year-on-year decrease in output compared with March 2020. Among them, the output of optical cable was 26.213 million core kilometers, up 14.2% year on year.
Pig iron output was 74.745 million tons, up 8.9% year on year; Crude steel output was 94.021 million tons, up 19.1% year on year; The steel output was 119.872 million tons, up 20.9% year on year; Ferroalloy production was 3.095 million tons, up 1% year on year; The output of alumina was 6.537 million tons, up 11.3% year on year; The output of refined copper (electrolytic copper) was 870000 tons, a year-on-year increase of 18.2%; The output of primary aluminum (electrolytic aluminum) was 3.276 million tons, up 8.5% year on year; The output of aluminum alloy was 870000 tons, a year-on-year increase of 23.9%; The output of copper products was 1.815 million tons, a year-on-year decrease of 2.9%; Aluminum production was 5.367 million tons, up 17.6% year on year.
The output of generating units (generating equipment) was 12.429 million KW, up 17.6% year on year; The output of optical cable was 26.213 million core kilometers, up 14.2% year on year; The output of lithium-ion batteries was 1929.547 million, up 52.7% year on year; The output of solar cells (photovoltaic cells) was 18.336 million KW, up 52.4% year on year.

What are the advantages of pre branched cables

Pre branched cable is a kind of cable which is prefabricated according to the user’s design drawing when the factory produces the main acsr cable. What are the advantages of pre branched cable? How to install pre branched cable? Pre branched cable is a new technology product in recent years, which is prefabricated according to the user’s design drawing when the factory produces the main cable.


The branch line factory is pre manufactured on the main cable. The section size and length of the branch line are determined according to the design requirements, which greatly shortens the construction period, greatly reduces the material cost and construction cost, and greatly ensures the reliability of power distribution.
1、 Overview of pre branching cable is to do pre branching on common cable models, such as VV, YJV cross-linked cable, fireproof cable, air tightness, dust prevention and waterproof of branch joint, so as to avoid cable failure caused by cable joint.


The pre branched cable consists of four parts
(1) Backbone cable;
(2) Branch line;
(3) Branch connector:
(4) There are three types of accessories: ordinary type, flame retardant type (Zr) and fire resistant type (NH). Pre branched cable is an alternative product of bus duct power supply in high-rise buildings. It has the advantages of reliable power supply, convenient installation, good waterproof, small building area, low failure rate, cheap price, maintenance free and so on. It is suitable for distribution lines with AC rated voltage of 0.6/1kv. It is widely used in vertical power supply of high and medium rise buildings, residential buildings, commercial buildings, hotels and hospitals, as well as in power supply systems of tunnels, airports, bridges and highways.
Main performance of prefabricated branch cable:
(1) Insulation resistance ≥ 200m Ω;
( 2) Insulation withstand voltage ≥ 3.5kv/5min;
(3) Good air tightness and waterproof, that is to say, immerse the branch joint in water, measure the insulation resistance and power frequency withstand voltage between water and cable core, both of which shall meet the requirements of 1 and 2.


(4) The ratio of contact resistance to reference resistance of equal length branch line is less than 1.2;
(5) The change rate of contact resistance ratio after short circuit is less than or equal to 0.2;
(6) Zr-yjv flame retardant prefabricated branch cable, sheath self extinguishing time ≤ 12s, in line with the requirements of gb12666.5;
(7) NH fire-resistant cable can not only supply power under normal working conditions, but also keep normal operation for 90min under burning conditions, meeting the requirements of gb12666.6.
(8) The maximum working temperature of copper core of VV cable is 70 ℃, and that of YJV cable is 90 ℃( 9) It has excellent corrosion resistance and can resist the corrosion of inorganic salt, oil, alkali, acid and organic deep agent;
(10) YJV type prefabricated branch aac cable has excellent thermal stability and anti-aging property.
(11) Gwdz, wdza, wdna, wdzan – clean prefabricated branch cables have the advantages of low smoke, low toxicity, halogen-free and fire resistance.
(12) Gzr-yjv chlorine barrier series branch cable. It has high flame retardancy, fire resistance and flame retardancy, exceeding class a of flame retardancy standard.
Advantages of pre branched cable:
(1) Excellent shock resistance, air tightness, waterproof and fire resistance.
(2) The main cable conductor has no joint, good continuity, reducing the probability of failure.
(3) Adopt advanced fully mechanized crimping technology to avoid the influence of human factors.
(4) It can be customized, and the branch position can be set according to the needs of the distribution point of the distribution system.
(5) The contact resistance of the branch is very small, and it is not affected by thermal expansion and cold contraction.


(6) Reduce the cost of distribution and engineering, high economic index, obvious comprehensive benefits.
(7) The installation is simple, the construction period is short, and the installation time is greatly reduced compared with the enclosed bus duct.
(8) After installation and operation, it is free of maintenance and does not need any maintenance at ordinary times.
2、 Pre branched cable structure
It is mainly composed of cable conductor, insulating layer, shielding layer, protective layer and pre branched cable connector, which is mainly used for power transmission; Because it is directly processed in the cable factory, there is no need to strip the cable on site as a branch, thus maintaining the complete electrical performance of the cable. The following is the structure diagram of power cable connector:


There are three types of branch joints: U-type, C-type and O-type, whose quality exceeds the national standard and reaches the international level. The branch opening of pre branched cable can be customized according to the site requirements, which can be up or down.
(1) Model: yfd-31 dimension: 180 × forty-four × 22mm applicable cable outer diameter: 50-150m2
(2) Model: yfd-32 dimension: 240 × fifty-five × 25 mm applicable cable outer diameter: 185-300 M2
(3) Model: yfd-33 dimension: 180 × forty-four × 22mm applicable cable outer diameter: 50-150m2
(4) Model: yfd-34 dimension: 240 × fifty-five × 25 mm applicable cable outer diameter: 185-240 M2
(5) Material: it is made of BMC (fiber reinforced unsaturated polyester molding compound) with excellent electrical and mechanical properties.
(6) Features and application: anti eddy current, flame retardant, non absorbent, high strength, easy installation, etc. Ensure that the cables in the electrical shaft are arranged in order, without cross arrangement, which can not only prevent eddy current loss, but also prevent the cables from moving due to external force or self weight. It is used for fixing the main power supply cable and emergency lighting cable in the electrical shaft of high-rise or multi-storey buildings. Because of its convenient installation, saving manpower and material resources, especially can replace the cable tray, it is a cable clamp product with high cost performance.
3、 Branch cable selection instructions
(1) For lighting and power transmission trunk system of general places or equipment, the “VV” type or “zr-vv” type shall be selected when the average ambient temperature is below 35 ℃.
(2) For the lighting and power transmission trunk system of places or equipment with fire protection requirements, the “YJV” type or “zr-yjv” type shall be selected when the average ambient temperature is above 35 ℃.
(3) “Nh-vv” type or “nh-yjv” type shall be selected for transmission line system with special fire protection requirements or fire protection equipment.

How to distinguish the quality of photovoltaic line?

Solar energy technology will become one of the green energy technologies in the future. Solar energy cable is becoming widely used in China. In addition to the rapid development of government-supported photovoltaic power plants, private investors are also actively building plants and plan to put them into production and sell them globally. Solar modules. Many countries are still in the learning stage. There is no doubt that in order to obtain the best profits, companies in the industry need to learn from countries and companies that have years of experience in solar energy applications. The construction of cost-effective and profitable photovoltaic power plants represents the most important goal and core competitiveness of all solar manufacturers.


How to choose fiber optic cable for us?
1. Outer: Indoor optical cables generally use polyvinyl or flame-retardant polyvinyl. The appearance should be smooth, bright, flexible and easy to peel off. The outer skin of poor quality optical fiber cable is not smooth and easy to adhere to the tight sleeve and aramid inside.

The PE sheath of the outdoor optical cable should be made of high-quality black polyethylene. After the cable is formed, the outer skin is smooth, bright, uniform in thickness, and free of small bubbles. The outer skin of inferior fiber optic cable is generally produced with recycled materials, which can save a lot of cost. The outer skin of this kind of fiber optic cable is not smooth. Because there are many impurities in the raw material, the outer skin of the made fiber optic cable has many very small pits. water.


2. Optical fiber: Regular optical fiber cable manufacturers generally use grade A cores from large factories, and some low-cost and inferior optical cables usually use grade C, grade D optical fibers and smuggled optical fibers from unknown sources. These optical fibers take a long time to leave the factory due to their complex sources. It is often damp and discolored, and single-mode fibers are often mixed in multimode fibers. Generally, small factories lack the necessary testing equipment and cannot judge the quality of the fiber. Because such optical fibers cannot be distinguished by the naked eye, the common problems encountered in construction are: narrow bandwidth and short transmission distance; uneven thickness and cannot be connected to the pigtail; the optical fiber lacks flexibility and breaks when it is bent.

3. Reinforced steel wire: The steel wire of the outdoor optical cable of the regular manufacturer is phosphated, and the surface is gray. Such steel wire does not increase hydrogen loss, rust, and has high strength after being cabled. Inferior fiber optic cables are generally replaced by thin iron or aluminum wires. The identification method is easy-it is white in appearance and can be bent at will when it is pinched in the hand. The optical fiber cable produced with such steel wire has a large hydrogen loss, and after a long time, the two ends of the hanging optical fiber box will rust and break.

4. Steel armor: regular production companies use double-sided brushed anti-corrosion paint longitudinally wrapped pattern steel strips, inferior optical cables use ordinary iron sheet, usually only one side of the anti-rust treatment.


5. Loose tube: The loose tube of the optical fiber in the optical cable should be made of PBT material, which has high strength, no deformation and anti-aging. Inferior fiber optic cables generally use PVC as the sleeve. The outer diameter of such a sleeve is very thin, and it is flattened by pinching it with the hand. It is a bit like a straw for drinking.

6. Fiber paste: The fiber paste in the outdoor optical cable can prevent the fiber from oxidizing. Due to moisture ingress and dampness, the fiber paste used in inferior fibers is very small, which seriously affects the life of the fiber.


7. Aramid: Also known as Kevlar, it is a high-strength chemical fiber that is currently used most in the military industry. Military helmets and bulletproof vests are produced from this material. At present, only DuPont and the Dutch Akzo can produce them, and the price is about 300,000 tons. Indoor optical cables and power overhead optical cables (ADSS) both use aramid yarns as reinforcements. Because aramid costs are relatively high, inferior indoor optical cables generally have a very thin outer diameter, which can save costs by using fewer strands of aramid. Such optical cables are easily broken when they are threaded through the tube. Because ADSS optical cable determines the amount of aramid fiber used in the optical cable according to the span and wind speed per second, it is generally not afraid to cut corners.

Five Main Types of Cable

1.What are the types of cable?
The wire products used to transmit electric (magnetic) energy, information and realize the conversion of electromagnetic energy are collectively referred to as wires and cables. According to different purposes, wires and cables can be divided into five categories:

(1). Bare conductors: products with only conductors without insulation, such as steel core aluminum stranded wire(ACSR cable), aluminum stranded wire, and copper stranded wire. Products are mainly used in suburbs, rural areas, user main lines, switch cabinets, etc.

(2). Winding wire (magnet wire): In the form of a winding, the magnetic line of force is cut in a magnetic field to induce current, or a wire that generates a magnetic field with current. It is mainly used in various motors, instruments and meters. Such as enameled wire.

(3). Power cables: Cable products used to transmit and distribute high-power electrical energy in the backbone of the power system, such as cross-linked polyethylene (xlpe) insulated power cables. The products are mainly used in the transmission of strong electric energy in power generation, distribution, transmission, transformation, and power supply lines, with large current (tens of amperes to several thousand amperes) and high voltage (220V to 500kV and above).

(4). Communication cables and optical cables: cables and optical cables that transmit telephone, telegraph, television, radio, fax, data and other telecommunication information.

(5). Wires and cables for electrical equipment: Wires and cables used to directly transmit electrical energy from the power distribution point of the power system to the power connection lines of various electrical equipment and appliances. Such as control cables, wiring wires, etc.

2. What are the application of Cable?
Power system: The wire and cable products used in the power system mainly include overhead bare wires, busbars (bus bars), power cables (plastic cables, oil-paper cables (basically replaced by plastic power cables), rubber-sheathed cables, overhead insulated cables), Branch cables, electromagnetic wires, electrical equipment wires and cables for power equipment, etc.
Information transmission system: The wires and cables used in the information transmission system mainly include local telephone cables, television cables, electronic cables, radio frequency cables, optical cables, data cables, electromagnetic wires, power communications or other composite cables.
Mechanical equipment, instrumentation system: Except for overhead bare wires, almost all other products have applications, but mainly power cables, electromagnetic wires, data cables, instrument cables, etc.

3. What is the basic structure of wire and cable?

Conductor: An object that conducts current. The specifications of wires and cables are expressed by the cross-section of the conductor.
Insulation:
The insulating material is wrapped on the outside of the conductor in different thicknesses according to the requirements of its withstand voltage.
Protective layer: the part that protects the cable.