Jack knowledge about cable:Safety requirements of the cable

In the power transmission , especially in modern super high voltage and high voltage power transmission process , the security is often a very important issue . It plays an important role in the power transmission cables which security demands? Power cable companies who generally have the following five points.

1 cable cross each other , the high-voltage cables should be below the low-voltage cables . If one of the cables around the crossing point within the range of 1m or wear protective tube separated by a partition , the minimum allowable distance of 0.25m.

2 cables with heat pipe close to or intersect , if insulation measures , a minimum distance of parallel and intersecting 0.5m respectively and 0.25m.

3 cable railway or road intersection should wear protective tube to protect the pipe should extend beyond 2m rail or road .

4 cables from the building foundation should be able to ensure that the cable is buried outside the building bulk water ; cable into the building should wear protective tube , the tube should be beyond the protection of bulk water outside the building .

5 should distance between the ground directly buried cables and grounding devices generally 0.25 ~ 0.5m; direct buried cable burial depth , generally not less than 0.7m, and should be buried in the permafrost .

Cultivate the world brand is the route one must take to enhance the international competitiveness Chinese cable industry

In April 11th, state quality inspection administration director Chinese Zhi Shuping at the Boao forum for Asia 2014 said the first "brand of Asia" points on the BBS, the past 30 years, "China manufacturing" all over the world market, but Chinese brand in the international competition is still in the vulnerable. In 2013, there have been 96 China enterprises to enter the "wealth" list of the world's top 500 enterprises, but a few years into the "world brand 100 strong" and "best global brands list" China brands are scanty.

An important symbol of industry powerful is has a number of world-class brand of large enterprises, which will play an important role in many aspects: to enhance the overall competitiveness of national industry standards, improve the international counterparts in the discourse right, enhance the country's export capacity, to enhance the national brand awareness, make it easier for enterprises to obtain trade at a premium in the international trade.

The annual output value of Chinese wire and cable industry trillion yuan in line with the image China the vigorous development of the country, but in recent years, thousands of companies from the ground situation, the lack of a sufficient number of world-class giant enterprises are to a certain extent constraints of industrial development. Therefore, the community generally believes that the industry is big but not strong. According to cable network (cableabc) reporter understanding, the Far East cable led the domestic top five leading cable enterprises accounted for the national market share of less than 10% of the sum of the cable. While the French top five cable company turnover accounted for the country's market 90%; America before the ten cable companies accounted for the country's 67% of the market; Japan's seven cable companies won the 86% of the national market. While the global 1/4 wire and cable market, has been Prysmian, Alcatel, USA general cable, wire and cable giants occupy 8.

Dongguan Anmei Lubrication Technology Co. Ltd. cable technology department director Feng Jun in 2014 Chinese (Changzhou) electric wire and cable equipment and materials exhibition received cable network (cableabc) said when interviewed by reporters, the domestic cable industry, although the enterprise quantity many, but the annual output value of over 10 billion yuan less, the world famous brand enterprise is less, while the developed countries not.

"A brand is not easy, not easy to brand." Huadong power cable company CEO in the second China (Wuhu) electric wire & cable exposition and the quality of the products the summit lamented. The domestic cable companies in the promotion for the road world class brand, is also faced with domestic trouble and foreign invasion "".

On the domestic, disorderly market competition compression of the domestic enterprise market so as to restrict the birth of the world brand. "Many manufacturers in order to reduce the cost of the Copperbelt of choice, and strip thickness will affect the service life of the cable." General manager, Henan Shenghua wire Co. Ltd. senior economist Zhang Laicheng, combined with years of experience in dealing with the cable companies, the problems existing in the reality.

Bad money drives out good phenomenon in cable industry is not uncommon, "many domestic cable companies in order to more for orders, competing to keep the prices down, leading to the high and low prices by 30% to 40%, or even more, and sometimes even less than the price of materials." Far east Holding Group chairman of the board Jiang Xipei to cherish an undying means low price or the lowest bid this illegal competition.

On abroad, Prysmian, Alcatel, American general cable and other international giants to carve up the China cable market in the heart of the obvious. For most China enterprises, because its management, technology, products, services and other than these foreign giants are not a small gap, so in the confrontation of seldom win, especially in the "tall" submarine cable and other products. This situation not only directly affect the domestic enterprise product market share, but also to some extent a booster of small enterprise more the use of illegal means to compete for the market.

Chinese cable industry needs more nurturing world brand in the process from big to strong in. From the government a series of reform measures, will be for the domestic cable industry cultivate the world brand to add a lot of confidence. Of course, Chinese cable industry and enterprise also needs to purify the market environment, improve the technical level, enhance the ability of product research and development, strengthen management capabilities and efforts.

hi,long time no see!

hi,everybady long time no see!

i have got a India friend yesterday!We are glad to met each other!

he is my first Foreign friend,it's so cool!

i wish i can get more  Foreign friends!

Jack knowledge about cable:Jack knowledge about cable:knowledge of Fireproof cable

With ten years of development blowout cabling industry , a growing number of internationally renowned manufacturers saw the huge potential of the Chinese market, the first to enter the Chinese manufacturers such as Compton , have Mimi eat a big fat , the more An increasing number of manufacturers want to enter the Chinese market share. Thus , with the end of the era of low and profits , the major manufacturers have come up with their own special skill , desire to dominate the market because of a maturing market has not just rely on international brand awareness and the introduction of foreign technology will be able to gain the initiative right , and to consider how to keep more of the overall pace of development China cabling industry , how can the introduction of foreign technology and marketing and transformation of localization in order to expand its market share in China.

In the network transmission is the most valuable information instead of network equipment. There was such a news , a certain public house on fire, she would only hold a drawer to escape from the scene , the people asked her what ah ! So precious ? She said this is my small to large photos, other things are valuable , and photos are priceless , burned it forever gone. Visible information is non-renewable, it never once lost , so people do everything possible to back up the data through a variety of means to send data through a stable network , placed them in a safe place . People gradually integrated wiring system against external invasion and avoid turning the direction of the external hazards , so the cable fire became their top priority.

It is often said Shuihuowuqing since man discovered fire, and the fire is not only accelerated the development of human civilization , but also to bring the destruction of human civilization , many ancient civilizations destroyed by fire . Similarly, the fire also burned cabling system that allows network transmission interruption. Also, if the cable produce large amounts of toxic gases and soot in the combustion process , the escape would have a significant impact on staff , and even become safety hazards. Therefore, countries engineers are stepping up research personnel for data backup and more secure fire lines .

Fireproof cable type

Wider application of the fire at this stage there are UL Series cables and flame retardant cable LSZH cable into two categories. Import products mainly from the Americas and Europe , due to the fire cable standard in America and Europe are not compatible , fire ideas are very different , and therefore , in the choice of the Party and the Institute products are in a passive state , each with its own the truth, often end up in accordance with the actual situation of funds to choose from.

UL flammability standards mainly in the following grades : CMP, CMR, CM, CMG, CMX.

1 ) booster stage -CMP level ( air combustion test / Tolstoy sodium duct experiments Plenum Flame Test / Steiner TunnelTest)
It is UL fire safety standards in the most demanding cable (Plenum Cable), the applicable safety standards UL910, experimental device specified in the horizontal ducts laying multiple samples , (300,000 BTU / Hr) gas burner combustion 87.9KW 20 minutes . Eligibility criteria for the flame must not extend beyond the gas burner flame front from 5 feet . The maximum peak optical density of 0.5 , the average value of the maximum density of 0.15 .
Such cables are usually installed in the CMP pressurized air return ducts or ventilation system air handling equipment used in Canada and the United States is recognized using . Good flame retardant performance meets UL910 standard FEP / PLENUM materials, flame retardant than meets IEC60332-1 and IEC60332-3 standard halogen material , burning up the concentration of smoke is low.

2 ) Riser -CMR level ( vertical burning test Riser Flame Test)
This is a commercial grade UL standard cable (Riser Cable), the applicable safety standards UL1666. In the simulation experiments predetermined vertical axis Cable samples , the gas burner with a predetermined 154.5KW (527,500 BTU / Hr) 30 min. Eligibility criteria for the flame can not spread to the upper 12 feet high room. Riser cable is not smoke concentration norms , generally vertical and horizontal cabling for floor use .

3 ) commercial grade -CM level ( vertical burning test Vertial Tray Flame Test)
This is a commercial grade UL standard cable (General Purpose Cable), the applicable safety standards UL1581. Experimental regulations laying multiple samples on a vertical stand 8 feet high , with a prescribed burn at 20KW (70,000 BTU / Hr) 20 minutes. Eligibility criteria for the flame can not spread to the upper end of the cable and self-extinguish . Similar UL1581 and IEC60332-3C, just different cabling roots. Commercial-grade cable is not smoke concentration standard, generally used only on the same floor level traces should not be used on vertical wiring floors .

4 ) General Purpose -CMG level ( vertical burning test Vertial Tray Flame Test)

It is common to UL standard grade cables (General Purpose Cable), the applicable safety standards UL1581. Similar to the commercial and general level of test conditions , the same as approved for use in Canada and the United States . General Purpose Cable specification does not smoke concentration , generally apply only to trace the same floor level , should not be used on vertical wiring floors .

5 ) household level - CMX level ( vertical burning test Vertial Wire Flame Test)
This is the UL standard household -level cable (Restricted Cable), the applicable safety standards UL1581, VW-1. Experimental samples provisions remain vertical , with the torch burning test (30,000 TU / Hr) 15 seconds, then stop for 15 seconds , repeated 5 times. Eligibility criteria for the flame must not exceed 60 seconds remaining , the sample can not burn more than 25% , the pad at the bottom of surgical cotton falling objects can not be ignited . UL1581-VW-1 similar to IEC60332-1, just different burning time . This grade does not smoke or toxic specification , only for laying a single cable system in a home or small office . These cables should be installed in bundles must casing. LSZH cables (LSOH).

LSZH cable by definition is less smoke after a fire , halogen-free cable. LSZH cable in principle is to let the flame does not produce a lot of gas and smoke when burned , so that people will not burn a lot of harm caused , greatly improving the survival rate of people in the fire.

LSZH cable test requirements, meet three requirements:
Flammability Requirements: You must have flame retardant LSZH cable . There are two flame retardant grades were required to comply with IEC 60332.1 ( a single cable vertical burning test ) and IEC 60332.3C ( vertical flame spread of bunched cable test ) . IEC 60332.1 which requires the use of a common flame retardant cable requirements, and IEC60332.3C requires relatively high level of flame retardant belong trunk .
Smoke density requirements : LSZH cable to carry the smoke density test . It is used in a confined space fire burning cables until the flame is extinguished after the final indoor smoke density test , required in the case of cigarettes , the ability to reach 60% light transmission , thus ensuring that people can see the smoke road .

Toxicity requirements: current toxicity testing methods several species, such as mice test and so on. In LSZH cable is used in halogen acid gas emission test ( test for low halogen ) and gas acidity test ( for halogen-free test ) . The test principle is halogen gas material at high temperatures ( respectively 800 ℃ and 935 ℃) generated by the analysis method to determine the halogen content .

Describes some of the information IEC 60332.1 level equivalent to the requirements of UL CM (IEC 60332.2 is a small diameter cable testing methods , alternative testing methods that can not be used when testing using 60332.1 ), IEC60332.3C equivalent to the requirements of UL CMR level . In fact, this four standard test methods are not the same , can not be directly compared.

In summary , the formation of two series of cables , one is flame-retardant cable CMX America ( U.S. standard cables clearly requires CMX halogen to increase the decomposition temperature of the cable ) ; the other is European FR / LSOH flame / LSZH cables.

Hi, I'm back, just to spend a happy holiday!

I just had a three-day holiday, great!

My friends and I went out to play one, to travel, to go picnic, we had a happy holiday! 
Good time is always short, I had to go to work!

But this is also very good, this is the true life!

Tired today, do not sharing the knowledge of the cable

Today's weather is weird, morning rain, then quickly turned into a sunny day!

As today relatively long on the outside, I feel very tired today, so today under lazy to steal, today's cable eliminating the need for knowledge sharing!

Jack knowledge about cable:knowledge of ground wire

In life, the ground wire is more commonly used as a cable, Here we give a brief knowledge of the ground wire! 
Ground wire is directly connected to the earth wire, also called safe return route, it put pressure direct danger to pass the Earth, considered a lifeline. 
Household appliances due to the poor insulation or humid environment will cause its shell with a certain static, in severe electric shock. In order to avoid such occurrences in the electrical wires may be connected to a metal housing at the other end of the wire to earth, once the electrical leakage occurs into the static ground line will release the earth. In addition to electrical maintenance personnel in the use of electric iron welding circuit, sometimes because of the charged electric iron and damaged electrical breakdown of the integrated circuit, which is more important. Friends sometimes use the computer to ignore the main case is grounded in fact, connected to the host computer root shell ground, to a certain extent, can prevent crashes phenomenon. 
In the power system ground: an important tool to have when the power voltage of equipment and lines appear unexpectedly assurance staff. By ministerial regulations, the ground wire must be more than 25mm 2 soft bare copper wire.

Brief introduction

Appliances, ground wire is connected to the electrical equipment enclosure and other parts in a timely manner will be due to various causes unsafe charge or leakage current export lines.

(1) high-voltage ground wire effect: high ground wire is used for lines and substation construction, to prevent near the charged body to ensure the safety of the use or misuse of electrostatic induction shock closing time. 
(2) high-voltage ground wire structure: portable high voltage ground wire from the insulated operating rod, wire clips, short routes, grounding wire, grounding terminals, bus clip, earth clamp. 
(3) high-voltage ground wire production process: the fine craftsmanship - wire clamp, earth clamp is made of high quality aluminum die casting; operating rod using epoxy color tube, good insulation properties, high strength, light weight, bright appearance smooth; soft ground using multi-strand copper wire twisted together high quality soft, and covered with soft, high temperature transparent insulating sheath can be worn on the ground to prevent the use of copper, copper wire fatigue testing requirements, ensure workers safety in operation. 
(4) ground wire Specifications: according to ministerial regulations, the ground wire must be more than 25mm 2 soft bare copper wire.

Resistance requirements

High short-circuit ground wire to ground resistance requirements determine the quality of the ground wire, generally in accordance with the power industry DL-T879-2004 technical requirements of each cross-sectional area of ​​the ground wire to ground resistance is not greater than the following values: 
DC resistance is measured between the lugs, 
For 16mm2, 25mm2, 35mm2, 50mm2, 70mm2, 95mm2, 120mm2 various sections, 
Average per meter were less than the resistance value should 1.24mΩ, 0.79mΩ, 0.56mΩ, 0.40mΩ, 0.28mΩ, 0.21mΩ, 0.16mΩ.

High voltage ground wire classification

(1) high-voltage ground wire in accordance with the use of the environment can be divided into: indoor busbar grounding wire (JDX-NL) and outdoor line-type ground wire (JDX-WS). (2) high-voltage ground wire in accordance with the voltage level can be divided into: 10KV ground wire, 35KV high voltage ground wire, 110KV grounding line, 220KV high voltage ground wire, 500KV high voltage ground wire 
Instructions for use 
(1) When mounted ground: first link earth clamp, followed by electrical connection clip; When removing the grounding line, the program must first disconnect power clip, after the demolition of the grounding clip. 
(2) Installation: soft copper phase grounding copper nose on his eyes fixed on the ground rod grounding Clips (electrical connection there are the fixed and movable) corresponding position on the monocular copper nose on the ground conjunct fixed on the ground or ground pin clip, constitute a complete set of ground wire. 
(3) verification of voltage levels and ground rod to operate the equipment are the same voltage level. 
(4) Ground partakers with soft copper and modular, grounding rods have flat type and double reed hook clamp.

Maintenance

Before using portable short-circuit ground wire should confirm a priori power outage, make sure no voltage on the device after the. First grounding clamp connected to the ground network or flat iron, then stick with a ground operation wire end line classes were tightened on the device leads. When removing the short-circuit ground wire, coinciding with the opposite order. 
Short-circuit ground wire installed from it and live equipment, taking into account the impact of the grounding wire pendulum, its safe distance should not be less than the value of the new regulations, "electricity safety regulations."

Prohibited method but with winding is shorted to ground without clamp.

Suspension points if ground, use copper for grounding clamp or a dedicated ground connection; If no fixed ground available; are available temporary grounding, grounding buried depth should not be less than 0.6m. 
Portable short-circuit ground wire should be properly kept. Before each use, check carefully whether it should be in good condition, no bare annealed copper wires exposed, no loose nuts shall not be used. 
Portable short-circuit ground wire test cycle every five years, with factory inspection test items. After passing the test of portable short-circuit ground wire after being subjected to short-circuit, short-circuit current withstand should be based on the size and appearance inspection judgments in general should be scrapped

If you are not happy, speak out to anyone!

Today i met a very troublesome problem, like a long time the solution is not found!

Also a sad day, how is that not forget, every think will be more sad!

Finally, finally could not stand it, find a friend to talk to him trouble again, although the last did not solve the problem, but in the end a better mood!

So what would say unhappy things out, even if not solve the problem, the mood will be better!

Review, summarize recent knowledge of the cable!

Recently, Jack has to share the nine cables knowledge blog!
To share a lot of knowledge of the cable, the cable basics knowledge, Main introduces three categories according to the application, gave a briefing on the knowledge of the power cable, Main introduce power cable history, type and structure! And how to buy power cable.
Then gave a briefing on fiber optic cable, xlpe cable, AAC (Aluminum alloy cable) cable, high voltage cable, control cable and other cables commonly used structures and uses, and gave a briefing specifically Wire and cable manufacturing process, so that we With the understanding of manufacturing cables, yesterday, to everyone Distinguish between wire and cable, wire and cable let everyone have a deeper understanding!
To conclude, Jack has to share so much knowledge of the cable, it makes me feel very proud, I often see his old blog, to check whether there is an error, and every time can learn something new, today, as summed up, not to share the knowledge of the cable, I hope everyone can learn more things, thank you!

Bold attempt to identify the correct insisted on doing!

Recent work paid a lot of effort, but did not get the desired results!

Perhaps too eager, but I think now things are very meaningful to do, so I will not give up!

As long as I never have to be the right thing to try bold, trying to do and stick to it there is always rewarding!

Come on, for myself!