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    Home > Chemicals Industry > Chemical Technology > Demystifying the chaos of the industry Three truths about aluminum alloy cable connection terminals

    Demystifying the chaos of the industry Three truths about aluminum alloy cable connection terminals

    • Last Update: 2022-11-18
    • Source: Internet
    • Author: User
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    In the past two or three years, as aluminum alloy cables have increasingly become the hottest segment of China's cable industry, this emerging market that is expected to reach 300 billion yuan has never lacked various topics
    .
    The controversy surrounding solutions for connecting terminals for copper-aluminum cables has been raging
    .
    This aspect reflects the popularity of the domestic aluminum alloy cable market, but it also shows that this is still a niche that needs to be standardized
    .

    Looking back at the domestic industry news in the past two years, you will find that many companies often express their opinions
    around aluminum alloy cable connection terminals.
    Among them, professional cable connector manufacturers share scientific insights, and there are also companies with a shallow development history to put forward some views
    that are debatable in terms of credibility and professionalism.
    So the question is: what is the truth of the aluminum alloy cable connection terminal problem?

    Truth 1: Cable terminals and conductors do not need to have the same chemical composition

    Cable, whether it is a traditional copper cable or an aluminum alloy cable with more cost advantages but relatively high technical difficulty, as an industrial equipment, its requirements for safety, performance and durability are extremely high
    .
    The corresponding industry standards and national standards are the most effective way to
    judge whether the product is qualified.

    At present, the current national standard GB/T 9327-2008 "Crimped and mechanical connection fittings test methods and requirements for power cable conductors with rated voltage of 35kV and below" (modified to adopt IEC 61238-1:2003) stipulates that the terminal block should pass electrical test and mechanical test, of which 1000 AC thermal cycles is a test to test
    the safety performance of conductors and terminal blocks under working conditions 。 Simply put, whether the qualified terminal and conductor connection system is qualified is based on the test data and standards, and whether the terminal should have exactly the same chemical composition as the conductor is not required
    in IEC and GB standards.

    Frankly speaking, the so-called "aluminum cable connection terminal problem" does not exist
    .
    And the motivation of companies that create this topic to attract industry attention clearly requires investors and customers to be vigilant
    .

    Fact two: A technical controversy that doesn't exist

    There is a general consensus in the cable industry that the manufacturing standards for terminals and cable conductors are different, and their respective chemical composition requirements are also different
    .
    The current manufacturing standard for terminal blocks is GB/T 14315-2008 "Crimp type copper, aluminum terminal blocks and connecting pipes for power cable conductors", of which 4.
    1.
    2 clarifies the naming of copper-aluminum transition products, and in item 5.
    1, it stipulates that "aluminum is not lower than GB/T 3190 No.
    2 industrial pure aluminum (L2)"
    .
    The current national standard for the chemical composition of aluminum alloy cable conductors is GB/T 30552-2014 "Aluminum alloy wire for cable conductors", which stipulates that 6 grades of aluminum alloys can be used as cable
    conductors.

    It can be clearly found that the above two products are manufactured according to different national standards, and their material selection is also different, so there is no superiority or disadvantage
    .
    And this also shows again that the so-called connection terminal problem is actually "layman's jargon", because the so-called technical differences themselves do not exist
    .

    At this point, on the other hand, companies that have been grasping the "connection terminal problem" for a long time inevitably make people doubt their cognitive level and rigor in the professional field
    .
    China's aluminum alloy cable market is still in its infancy, and many unknown companies can still play a role, but there is no doubt that with the gradual maturity of the industry, truly scientific connection terminal solutions will be widely used
    .

    Fact 3: Forty years of applied practice in North America is the best proof of this

    Some companies that question the copper-aluminum transition terminal are too simple and direct in thinking about the problem of connecting terminals: one of the main reasons why aluminum alloy cables can be safely applied is because the joint safety performance is good, and the strong guarantee of good joint performance is the creep performance of aluminum alloy conductors
    .
    Since the joint is composed of an aluminum alloy conductor and a copper-aluminum transition terminal, only the conductor has better creep performance, and the aluminum part of the copper-aluminum transition terminal does not have, and the joint is also unreliable, so the aluminum part of the copper-aluminum transition terminal should also use materials
    with the same creep performance as the conductor.

    Such concerns do need to be taken into account
    in practical applications, especially when using bolt-on mechanical connections (e.
    g.
    T-terminals for cables).
    As everyone knows, they only consider the problem on the one hand, but ignore one point, the copper-aluminum transition terminal is usually crimped by confining pressure or pit pressure, this crimping has two characteristics: one is that the crimping force is large, far greater than the yield strength of the conductor, and creep happens to occur near the yield strength; Second, compared with creep deformation, the deformation of terminal crimping is huge
    .
    Combining the above two points, after crimping treatment, the effect of creep deformation has been completely weak to a negligible extent
    .
    Therefore, the so-called "unstable copper-aluminum connection terminals" statement is simply untenable
    .

    As the saying goes, practice is the only test of
    truth.
    In the industrial sector, the application time of the equipment is proof
    of the practical effect.
    Taking the North American market, which is currently the most mature aluminum alloy cable application in the world, Thomas Betts and Tyco terminal blocks widely used in aluminum alloy cable application projects, its material has 1000 series aluminum alloy, but also 6000 series aluminum alloy, creep performance is very excellent, perfect solution to the copper aluminum transition terminal aluminum part lack creep performance concerns
    。 Aluminum alloy cable and terminal block connection system has a safe operation history of more than 40 years in North America, has been successfully applied in a number of world-class major projects, so far there has been no problem, with practical results to show the scientific and rational solution it provides
    .

    Skeptics of copper and aluminum transition terminals may wish to reflect: If there is a real problem with copper and aluminum transition terminals, why have multiple projects and many customers in the US market never been questioned? Has no one discovered or considered a similar problem in forty years?

    In summary, for companies that continue to exaggerate the problem of connection terminals in the market, in the author's opinion, they can only be identified as cable companies
    that are good at "marketing" and blatantly ignore industrial laws and the basic logic of manufacturing.
    However, such a development idea, in the short term, in the immature Chinese aluminum alloy cable market may still be effective, but if it cannot withstand the test of time and practice, it will inevitably be eliminated
    by the industry in the long run.

    In the past two or three years, as aluminum alloy cables have increasingly become the hottest segment of China's cable industry, this emerging market that is expected to reach 300 billion yuan has never lacked various topics
    .
    The controversy surrounding solutions for connecting terminals for copper-aluminum cables has been raging
    .
    This aspect reflects the popularity of the domestic aluminum alloy cable market, but it also shows that this is still a niche that needs to be standardized
    .

    Aluminum alloy cable

    Looking back at the domestic industry news in the past two years, you will find that many companies often express their opinions
    around aluminum alloy cable connection terminals.
    Among them, professional cable connector manufacturers share scientific insights, and there are also companies with a shallow development history to put forward some views
    that are debatable in terms of credibility and professionalism.
    So the question is: what is the truth of the aluminum alloy cable connection terminal problem?

    Truth 1: Cable terminals and conductors do not need to have the same chemical composition

    Cable, whether it is a traditional copper cable or an aluminum alloy cable with more cost advantages but relatively high technical difficulty, as an industrial equipment, its requirements for safety, performance and durability are extremely high
    .
    The corresponding industry standards and national standards are the most effective way to
    judge whether the product is qualified.

    At present, the current national standard GB/T 9327-2008 "Crimped and mechanical connection fittings test methods and requirements for power cable conductors with rated voltage of 35kV and below" (modified to adopt IEC 61238-1:2003) stipulates that the terminal block should pass electrical test and mechanical test, of which 1000 AC thermal cycles is a test to test
    the safety performance of conductors and terminal blocks under working conditions 。 Simply put, whether the qualified terminal and conductor connection system is qualified is based on the test data and standards, and whether the terminal should have exactly the same chemical composition as the conductor is not required
    in IEC and GB standards.

    Frankly speaking, the so-called "aluminum cable connection terminal problem" does not exist
    .
    And the motivation of companies that create this topic to attract industry attention clearly requires investors and customers to be vigilant
    .

    Fact two: A technical controversy that doesn't exist

    There is a general consensus in the cable industry that the manufacturing standards for terminals and cable conductors are different, and their respective chemical composition requirements are also different
    .
    The current manufacturing standard for terminal blocks is GB/T 14315-2008 "Crimp type copper, aluminum terminal blocks and connecting pipes for power cable conductors", of which 4.
    1.
    2 clarifies the naming of copper-aluminum transition products, and in item 5.
    1, it stipulates that "aluminum is not lower than GB/T 3190 No.
    2 industrial pure aluminum (L2)"
    .
    The current national standard for the chemical composition of aluminum alloy cable conductors is GB/T 30552-2014 "Aluminum alloy wire for cable conductors", which stipulates that 6 grades of aluminum alloys can be used as cable
    conductors.

    It can be clearly found that the above two products are manufactured according to different national standards, and their material selection is also different, so there is no superiority or disadvantage
    .
    And this also shows again that the so-called connection terminal problem is actually "layman's jargon", because the so-called technical differences themselves do not exist
    .

    At this point, on the other hand, companies that have been grasping the "connection terminal problem" for a long time inevitably make people doubt their cognitive level and rigor in the professional field
    .
    China's aluminum alloy cable market is still in its infancy, and many unknown companies can still play a role, but there is no doubt that with the gradual maturity of the industry, truly scientific connection terminal solutions will be widely used
    .

    Fact <>: Forty years of applied practice in North America is the best proof of this

    Some companies that question the copper-aluminum transition terminal are too simple and direct in thinking about the problem of connecting terminals: one of the main reasons why aluminum alloy cables can be safely applied is because the joint safety performance is good, and the strong guarantee of good joint performance is the creep performance of aluminum alloy conductors
    .
    Since the joint is composed of an aluminum alloy conductor and a copper-aluminum transition terminal, only the conductor has better creep performance, and the aluminum part of the copper-aluminum transition terminal does not have, and the joint is also unreliable, so the aluminum part of the copper-aluminum transition terminal should also use materials
    with the same creep performance as the conductor.

    Such concerns do need to be taken into account
    in practical applications, especially when using bolt-on mechanical connections (e.
    g.
    T-terminals for cables).
    As everyone knows, they only consider the problem on the one hand, but ignore one point, the copper-aluminum transition terminal is usually crimped by confining pressure or pit pressure, this crimping has two characteristics: one is that the crimping force is large, far greater than the yield strength of the conductor, and creep happens to occur near the yield strength; Second, compared with creep deformation, the deformation of terminal crimping is huge
    .
    Combining the above two points, after crimping treatment, the effect of creep deformation has been completely weak to a negligible extent
    .
    Therefore, the so-called "unstable copper-aluminum connection terminals" statement is simply untenable
    .

    As the saying goes, practice is the only test of
    truth.
    In the industrial sector, the application time of the equipment is proof
    of the practical effect.
    Taking the North American market, which is currently the most mature aluminum alloy cable application in the world, Thomas Betts and Tyco terminal blocks widely used in aluminum alloy cable application projects, its material has 1000 series aluminum alloy, but also 6000 series aluminum alloy, creep performance is very excellent, perfect solution to the copper aluminum transition terminal aluminum part lack creep performance concerns
    。 Aluminum alloy cable and terminal block connection system has a safe operation history of more than 40 years in North America, has been successfully applied in a number of world-class major projects, so far there has been no problem, with practical results to show the scientific and rational solution it provides
    .

    Skeptics of copper and aluminum transition terminals may wish to reflect: If there is a real problem with copper and aluminum transition terminals, why have multiple projects and many customers in the US market never been questioned? Has no one discovered or considered a similar problem in forty years?

    In summary, for companies that continue to exaggerate the problem of connection terminals in the market, in the author's opinion, they can only be identified as cable companies
    that are good at "marketing" and blatantly ignore industrial laws and the basic logic of manufacturing.
    However, such a development idea, in the short term, in the immature Chinese aluminum alloy cable market may still be effective, but if it cannot withstand the test of time and practice, it will inevitably be eliminated
    by the industry in the long run.

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