{"id":4434,"date":"2026-09-27T19:22:18","date_gmt":"2026-09-27T19:22:18","guid":{"rendered":"https:\/\/huyuglobal.com\/?p=4434"},"modified":"2026-09-27T19:22:20","modified_gmt":"2026-09-27T19:22:20","slug":"for-electric-power-transmission-copper-or-aluminium-wire-is-used","status":"publish","type":"post","link":"https:\/\/huyuglobal.com\/fr\/blog\/for-electric-power-transmission-copper-or-aluminium-wire-is-used\/","title":{"rendered":"Pour la transmission d'\u00e9nergie \u00e9lectrique, utilise-t-on du fil en cuivre ou en aluminium ?"},"content":{"rendered":"

Lorsque vous regardez une ligne \u00e9lectrique, il est fort probable qu'elle soit en aluminium, bien qu'en laboratoire le cuivre soit un meilleur conducteur. Le facteur d\u00e9terminant pour l'utilisation de l'aluminium n'est pas l'\u00e9lectricit\u00e9 mais le poids, l'\u00e9tendue des port\u00e9es et le prix. Cet article pr\u00e9sente les usages de chaque mat\u00e9riau, explique pourquoi l'aluminium a d\u00e9j\u00e0 pr\u00e9valu sur le cuivre dans le cas des lignes de transmission a\u00e9riennes mais lui fait encore concurrence dans la transmission souterraine et les appareillages, et d\u00e9crit ce que cela entra\u00eene aux points de terminaison de la ligne.<\/p>\n

R\u00e9ponse courte : La plus grande quantit\u00e9 de transmission d'\u00e9nergie \u00e9lectrique a\u00e9rienne est r\u00e9alis\u00e9e par des fils en aluminium, qui repr\u00e9sentent plus de 90 % des fils de transmission d'\u00e9nergie import\u00e9s. Les fils en aluminium utilis\u00e9s pour la transmission d'\u00e9nergie \u00e9lectrique sont commun\u00e9ment appel\u00e9s ACSR, ce qui d\u00e9signe un fil en aluminium \u00e0 \u00e2me en acier. Les fils en cuivre sont utilis\u00e9s dans les cas o\u00f9 l'espace et la fiabilit\u00e9 des connexions doivent \u00eatre privil\u00e9gi\u00e9s par rapport au poids du fil, comme pour l'installation de c\u00e2bles, les barres omnibus, les moteurs et les transformateurs. L'aluminium transmet seulement 61 % de l'\u00e9lectricit\u00e9 que le cuivre transmet et son co\u00fbt est d'environ 25 \u00e0 30 % du co\u00fbt du cuivre, mais il p\u00e8se 70 % de moins que le cuivre, ce qui signifie qu'un fil en aluminium ayant la m\u00eame r\u00e9sistivit\u00e9 que le cuivre p\u00e8se environ deux fois moins car il a la m\u00eame r\u00e9sistance \u00e9lectrique qu'un fil en cuivre et est quelque peu plus large en diam\u00e8tre.<\/p><\/blockquote>\n

Les chiffres qui tranchent le d\u00e9bat<\/h2>\n

Les deux m\u00e9taux excellent dans la conduction de l'\u00e9lectricit\u00e9, mais la diff\u00e9rence est bien moindre que ce que la plupart des gens pensent lorsque nous ne comparons pas des fils de m\u00eame taille mais des fils de capacit\u00e9 \u00e9gale. Le cuivre est gagnant car il est plus volumique ; le cuivre peut transporter plus d'\u00e9lectricit\u00e9 pour un fil de m\u00eame surface. L'aluminium est gagnant gr\u00e2ce \u00e0 son poids sp\u00e9cifique ; il est significativement plus l\u00e9ger et beaucoup moins cher pour la m\u00eame conductance.<\/p>\n\n\n\n\n\n\n\n\n\n
Propri\u00e9t\u00e9 \u00e0 20 \u00b0C<\/th>\nCuivre \u00e9tir\u00e9 \u00e0 froid<\/th>\nAluminium \u00e9tir\u00e9 \u00e0 froid<\/th>\nAcier galvanis\u00e9<\/th>\n<\/tr>\n
R\u00e9sistivit\u00e9 (\u00d710-8<\/sup> \u03a9\u00b7m)<\/td>\n1.72<\/td>\n2.83<\/td>\nenv. 14<\/td>\n<\/tr>\n
Conductivit\u00e9 (1 % IACS)<\/td>\n97 (cuivre recuit 100)<\/td>\n61<\/td>\nenv. 12<\/td>\n<\/tr>\n
Densit\u00e9 (kg\/m\u00b3)<\/td>\n8,890<\/td>\n2,703<\/td>\n7,800<\/td>\n<\/tr>\n
R\u00e9sistance ultime \u00e0 la traction (MPa)<\/td>\n380-420<\/td>\n160-200<\/td>\n1,300-1,500<\/td>\n<\/tr>\n
Coefficient de temp\u00e9rature (\u00d710-3<\/sup>\/\u00b0C)<\/td>\n3.93<\/td>\n4.03<\/td>\n4.5<\/td>\n<\/tr>\n
Co\u00fbt relatif du mat\u00e9riau (indication 2026)<\/td>\n8 800-11 000 USD par tonne<\/td>\n2 400-3 200 USD par tonne<\/td>\nD\u00e9pend de l'application<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n

En termes d'ing\u00e9nierie, les implications deviennent claires. En ce qui concerne la r\u00e9sistance \u00e9lectrique, l'aluminium a environ 1,6 fois plus de surface que le cuivre, ce qui est environ 1,28 fois plus large que le cuivre. Cependant, malgr\u00e9 la taille de ce conducteur, il ne p\u00e8se qu'environ la moiti\u00e9. De plus, puisque les prix des mati\u00e8res premi\u00e8res pour la production d'aluminium sont significativement inf\u00e9rieurs \u00e0 ceux du cuivre, un conducteur en aluminium de m\u00eame taille co\u00fbte environ 35 \u00e0 50 % de son homologue en cuivre et est \u00e9galement 52 % plus l\u00e9ger.<\/p>\n

Alors que l'aluminium pr\u00e9sente un inconv\u00e9nient majeur en termes m\u00e9caniques. Sa r\u00e9sistance \u00e0 la traction est presque deux fois inf\u00e9rieure \u00e0 celle du cuivre. De plus, il pr\u00e9sente des inconv\u00e9nients sous charge prolong\u00e9e, car il subit un allongement.<\/p>\n

\"Les<\/p>\n

Pourquoi l'aluminium a gagn\u00e9 la ligne a\u00e9rienne<\/h2>\n

En divisant les deux responsabilit\u00e9s, le probl\u00e8me dispara\u00eet compl\u00e8tement. L'ACSR (Aluminium Conductor Steel Reinforced) se compose de fils d'aluminium \u00e0 l'ext\u00e9rieur et d'un noyau en acier et acier galvanis\u00e9 \u00e0 l'int\u00e9rieur. Le noyau en acier maintient la tension tandis que l'aluminium est responsable du transport du courant. L'acier joue presque aucun r\u00f4le du point de vue \u00e9lectrique puisqu'il est situ\u00e9 au c\u0153ur du conducteur, avec une densit\u00e9 de courant la plus faible dans ce type de conducteur. Le conducteur est d\u00e9sign\u00e9 comme 54\/7, ce qui signifie qu'il y a 54 fils d'aluminium autour des 7 brins du noyau en acier.<\/p>\n

Lorsque le conducteur est l\u00e9ger, la construction de l'ensemble du syst\u00e8me de transmission est moins co\u00fbteuse. Des fils plus l\u00e9gers permettent des port\u00e9es plus longues entre les pyl\u00f4nes, ce qui signifie moins de pyl\u00f4nes, des fondations plus petites et moins de terrain d\u00e9frich\u00e9. Selon diverses estimations de l'industrie, les \u00e9conomies pour l'infrastructure lorsque des syst\u00e8mes tout-cuivre sont utilis\u00e9s peuvent atteindre jusqu'\u00e0 20-40\u202f%. Sur des lignes plus longues, cet avantage d\u00e9passe tous les calculs d'efficacit\u00e9 de conductivit\u00e9.<\/p>\n

Il y a un autre avantage \u00e0 prendre en compte. Puisque la conception des conducteurs AC \u00e0 r\u00e9sistance \u00e9gale est environ 28\u202f% plus large en diam\u00e8tre, la charge \u00e9lectrique est r\u00e9partie plus uniform\u00e9ment \u00e0 la surface et l'effet de d\u00e9charge corona est att\u00e9nu\u00e9. Ce qui semble \u00eatre un exc\u00e8s de taille sur le chantier constitue un bon bonus au niveau de tension de 400 kV.<\/p>\n\n\n\n\n\n\n\n\n
Conducteur<\/th>\nConstruction<\/th>\nSource de r\u00e9sistance<\/th>\nO\u00f9 il est utilis\u00e9<\/th>\n<\/tr>\n
AAC<\/td>\nBrins tout aluminium<\/td>\nAluminium uniquement<\/td>\nPort\u00e9es courtes, barre omnibus de poste, distribution urbaine<\/td>\n<\/tr>\n
AAAC<\/td>\nBrins en alliage aluminium-magn\u00e9sium-silicium<\/td>\nAlliage<\/td>\nAtmosph\u00e8res c\u00f4ti\u00e8res et industrielles ; pas de corrosion bimetallique<\/td>\n<\/tr>\n
ACSR<\/td>\nAluminium sur noyau en acier galvanis\u00e9<\/td>\nNoyau en acier<\/td>\nLe standard pour la transmission a\u00e9rienne dans le monde entier<\/td>\n<\/tr>\n
ACAR<\/td>\nAluminium sur brins en alliage d'aluminium<\/td>\nNoyau en alliage<\/td>\nItin\u00e9raires sensibles \u00e0 la corrosion n\u00e9cessitant plus de r\u00e9sistance que l'AAC<\/td>\n<\/tr>\n
ACSS<\/td>\nAluminium recuit sur noyau haute r\u00e9sistance<\/td>\nNoyau, essentiellement tout le noyau<\/td>\nRehaussement d'un droit de passage existant ; haute temp\u00e9rature de fonctionnement<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n

Where copper still wins, and why<\/h2>\n

The underground cable is the last bastion of copper in the cable industry, and the reason for that is the issue of space. A trench, duct, or cable tray has a predetermined space, and any extra square millimeter of the conductor needs to be justified by digging, ducting, and pulling efforts. Wherever there is a need for a large cross-section, copper conductivity wins the competition. Underwater use creates one more rationale for copper use: strong construction for long supportless runs and at the entry points where cable is pulled.<\/p>\n

In electrical devices the picture is even clearer. Busbars, motor and transformer windings, contactor coils, control wires are all made of copper, since the housing has a fixed size, and connection quality manifests itself more than price of metal. 3,200 A of electrical busbar made out of copper should have about 1.6 times smaller section made of aluminum which normally does not fit. DC traction (metro third rail and overhead systems, arc furnaces, electrolytic plants) remains with copper for the same purpose.<\/p>\n

Then there is the conversion argument: any current system constructed from copper cannot be transitioned into aluminum without changing all the assumptions regarding ampacity, fault ratings and protection settings at the same time.<\/p>\n

The failure modes that gave aluminium a bad name<\/h2>\n

Aluminium has gained a bad reputation that it has largely earned \u2014 but it is not the material’s fault. During a time of unprecedented copper costs, it was then assumed that the same technologies, devices, and torque values being used on copper would also work when using aluminium in homes in North America. Three properties then played into the situation.<\/p>\n

First, aluminium reacts with oxygen and forms an oxide coating, which is an insulating material that has a melting point of around 2,072 \u00b0C; thus, it is good for corrosion-resistance and not good for screw terminals. Secondly, aluminium expands significantly more than copper during thermal cycles; therefore, the connection made is going to be loose after a great number of thermal cycling. Thirdly, since aluminium is anodic to copper, the presence of moisture causes galvanic corrosion of the contact whenever there is a direct contact of the two metals.<\/p>\n

All these problems lead to one classic failure: a receptacle getting warm enough to develop arcs. The solutions for making modern aluminium wiring safe are oxide inhibiting compound applied directly at connections, CO\/ALR-rated devices used especially for aluminium conductors, bimetallic transition connections between copper and aluminium, as well as torque values calculated and considered in respect of expanding properties of aluminium.<\/p>\n

For anyone working on existing aluminium branch circuits, the diagnostic is heat rather than appearance. A termination that has begun to fail will usually show discoloured insulation, a scorched device or nuisance tripping long before it fails outright, and the same fingerprint \u2014 warmth under light load, then trips that make no sense \u2014 is how you catch a breaker that has gone bad<\/a> at the other end of the circuit.<\/p>\n

Matching the conductor to the voltage class<\/h2>\n

The way power is transmitted changes as the transmission voltage changes, and the change is caused by geometry and not economics.Above roughly 220 kV, lines carry more than one conductor per phase, and the same logic that governs the difference between high voltage and low voltage<\/a> design decides how many. A 400 kV line commonly runs two or four sub-conductors per phase in a bundle rather than one very large conductor.<\/p>\n

The change in power transmission has to do with inductance and corona effects. Inductance of a power line is determined only by the physical radius of the wire, and the increase of the radius of a single wire does not have much influence on inductance. To make it effective, wires are bundled into a number of smaller wires, therefore, the effective radius increases with the number of wires, while maintaining the electric field at the surface low enough to avoid corona. Hence, the aluminum content in the wires grows with voltage, and the design of the wires is done beforehand, thus it does not depend on the manufacturer.<\/p>\n\n\n\n\n\n\n\n
ACSR code name<\/th>\nStranding Al \/ steel<\/th>\nOverall diameter<\/th>\nDC resistance at 20 \u00b0C<\/th>\nUtilisation typique<\/th>\n<\/tr>\n
Dog<\/td>\n6\/4.72 + 7\/1.57<\/td>\n14.15 mm<\/td>\n0.2745 \u03a9\/km<\/td>\n33-66 kV lines<\/td>\n<\/tr>\n
Panther<\/td>\n30\/3.00 + 7\/3.00<\/td>\n21.00 mm<\/td>\n0.1390 \u03a9\/km<\/td>\n132 kV lines<\/td>\n<\/tr>\n
Zebra<\/td>\n54\/3.18 + 7\/3.18<\/td>\n28.62 mm<\/td>\n0.0688 \u03a9\/km<\/td>\n220 kV and 400 kV, bundled<\/td>\n<\/tr>\n
Moose<\/td>\n54\/3.53 + 7\/3.53<\/td>\n31.77 mm<\/td>\n0.0561 \u03a9\/km<\/td>\n400 kV, twin or quad bundle<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n

These names are derived from national conductor catalogs, while the figures that follow \u2014 including diameter, stranding, resistance, and geometric mean radius \u2014 are key considerations in designing a line. The first aspect concerning the substance of the conductor is resolved far in advance of reviewing the conductor table.<\/p>\n

\"Matching<\/p>\n

Ampacity, temperature and terminal ratings<\/h2>\n

The lower conductivity of aluminium extends to the ampacity tables as well. With the same conductor size, aluminium is able to conduct around 78-80% of the ampacity of copper at the same temperature rating for insulation. For example, a 1\/0 conductor rated at 75 \u00b0C presents an ampacity of 150 A in copper and an ampacity of 120 A in aluminium. In order to achieve the same ampacity level, it is necessary to use a larger conductor \u2014 the general rule is to use a conductor that is two AWG sizes larger than in copper.In the end, this brings the issue of the space \u2014the aluminium conductor that conducts the required current requires different raceway sizes, different lugs and more space at the panel.<\/p>\n

Two details in the code create most cases of errors in the field. The first one is the fact that ampacity depends on the temperature ratings of wiring and terminations. A 90 \u00b0C insulated conductor connected to a 75 \u00b0C rated terminal can only be used at the lower figure unless the assembly is listed otherwise, and that listing is exactly what a UL 489 molded case circuit breaker<\/a> declares in its terminal temperature rating rather than in its marketing literature. The second detail is that aluminium connections must be made using connectors that are listed as suitable for aluminium wiring, using the aforementioned torque and the oxide inhibitor according to the specifications of the connector manufacturer.<\/p>\n

What this means for switchgear and terminations<\/h2>\n

At this stage, the decision made by the conductor is no longer a decision regarding the wire, but one concerning the switchgear. The use of aluminium feeders requires that every piece of equipment connected to the wires is rated for both aluminium and copper; the termination equipment has to be bimetallic involving an aluminium and copper connection wherever aluminium is used with copper.<\/p>\n

HUYU’s manufacturing line makes components such as MCBs, MCCBs, air circuit breakers, contactors, relays, current transformers, surge protection devices, automatic transfer switches and PV combiner boxes. We do not produce wire, thus we do not view it to be up to us to make the choice between aluminium and copper.What we do is supply equipment whose terminals are rated for both, with the torque and conductor-range data published \u2014 a DIN-rail disjoncteur miniature<\/a> is only a 63 A device to the extent its terminals accept the conductor you bring to it.<\/p>\n

As we have learnt from our experience with failures in the field, it is important to remember that whenever a feeder changes material during a run, the junction of that change must be at a designated terminal or at a bimetallic connector \u2014 never half-way along a run with a split bolt and a piece of tape.<\/p>\n

How to decide on a real project<\/h2>\n\n\n\n\n\n\n\n\n\n
Application<\/th>\nMat\u00e9riau<\/th>\nRaison<\/th>\n<\/tr>\n
Overhead transmission and distribution<\/td>\nAluminium (ACSR \/ AAAC)<\/td>\nWeight, span length, tower cost, diameter and corona<\/td>\n<\/tr>\n
Underground and submarine cable<\/td>\nCopper, sometimes aluminium for large LV<\/td>\nCross-section is expensive; robustness at landing points<\/td>\n<\/tr>\n
Switchgear busbars and control wiring<\/td>\nCuivre<\/td>\nFixed enclosure volume; connection reliability<\/td>\n<\/tr>\n
Motor and transformer windings<\/td>\nCopper; aluminium in cost-driven distribution units<\/td>\nWinding space, losses, heat dissipation<\/td>\n<\/tr>\n
Building feeders, larger circuits<\/td>\nAluminium for size and cost; copper for tight routes<\/td>\nTrade-off between metal cost and raceway space<\/td>\n<\/tr>\n
Existing installations<\/td>\nMatch what is already there<\/td>\nAvoid re-rating studies and mixed-metal terminations<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n

System-level decisions often push the answer one step further. On a large industrial site, the conductor material interacts with the distribution architecture \u2014 how many transformers, how long the MV runs, how much MV switchgear \u2014 which is why enterprise-scale distribution systems<\/a> are designed as a whole rather than conductor by conductor, and why optimising the architecture usually saves more than the metal swap does.<\/p>\n

FAQ<\/h2>\n

Is aluminium or copper better for power transmission?<\/h3>\n

Aluminium is preferred for overhead lines by an enormous factor, with more than 90% of the global network employed in its use. Copper is better suited for underground lines, equipment, or situations where the cross-section is predetermined. They both have their strengths; the question then is which constraint applies to the situation in question.<\/p>\n

Why is aluminium used instead of copper in overhead lines?<\/h3>\n

This is because an aluminium conductor with the same resistance weighs only approximately half as much and costs about 35-50% of the price of the copper equivalent. The fact that the weight is half makes the spans longer and more towers and smaller foundations are needed to properly support the structure.<\/p>\n

Can copper and aluminium wires be connected directly?<\/h3>\n

Avoid using it in any damp or exterior area. Aluminium is electropositive to copper, which can cause galvanic action in the presence of moisture within the connection. Therefore, make sure to use special bimetal connectors designed specifically for the two metals.<\/p>\n

Does aluminium wire carry less current than copper of the same size?<\/h3>\n

Indeed, typically the Copper rating is around 78 to 80 percent for the same insulation temperature of the insulation. If you want the same amount of current and voltage, you’ll use about two AWG sizes up which would require bigger conductors and therefore bigger sizes of both raceways and lugs as well.<\/p>\n

What is ACSR and why is the steel core there?<\/h3>\n

The Aluminium Conductor Steel Reinforced (ACSR) is formed by placing a steel wire core at the centre of several layers of aluminum wires. The role of steel is to take the tensile stress that the hard drawn aluminum cannot manage on long spans, while the aluminum is responsible for carrying electrical current. Since steel is located in the central part of the conductor where the place for the electrical current is minimum, almost no electrical loss occurs.<\/p>\n

Is aluminium wiring in a house dangerous?<\/h3>\n

Not per se, but it does require proper device installation. The mistakes that happened in the 1960s and 1970s can be attributed to the use of aluminum wire connectors with devices that were not rated for such conductors, but were utilized without the appropriate installation or proper torque. Nowadays, with the use of the oxide-inhibiting compound, the devices rated for CO\/ALR rating, as well as bimetallic gadgets the process works correctly and efficiently under the condition that those requirements are fulfilled.<\/p>\n

R\u00e9f\u00e9rences<\/h2>\n