If you've recently been involved in power engineering, building power distribution, or new energy projects, you've likely heard the term "aluminum cable." Aluminum cables, also known as aluminum alloy cables or pure aluminum power cables, were once viewed with prejudice by some due to concerns about oxidation and joint failures. However, in the last decade, with the maturation of material processing and connection technologies, aluminum cables have quietly become a mainstay in many fields.

So, where exactly are aluminum cables used? In which scenarios are they a reliable choice, and in which are they unsuitable? Let's set aside complex technical parameters and explain their practical uses in plain language.

I. Power Distribution in Large Residential and Commercial Buildings
Aluminum cables are increasingly used in the main power supply systems of multi-story residential buildings, office buildings, and shopping malls. The reason is simple: in a 30-story residential building, the cables from the underground distribution room to the electrical shafts on each floor are often hundreds of meters long. Using only copper cables would significantly increase raw material costs; aluminum cables, however, are only about one-third the weight of copper, making them much lighter for the same cross-sectional area. This means that a single, thick cable can be moved and laid by just two people, eliminating the need for additional hoisting equipment and significantly improving construction efficiency.

Currently, the mainstream practice is to use aluminum alloy cables (such as YJHLV and ZC-YJHLV models) for the main trunk lines from the substation to the building's distribution box, while using copper wire for smaller branch lines inside the building. This combination of "aluminum trunk + copper branches" saves developers approximately 30%-40% on cable procurement costs while ensuring reliability.

One important detail to note: aluminum cable terminals must use copper-aluminum transition terminals and be coated with anti-oxidation conductive grease. Many past impressions of "aluminum cables being prone to problems" actually stemmed from the use of ordinary copper terminals, which loosened and overheated due to thermal expansion and contraction—a problem that can now be perfectly avoided through standardized construction practices.

II. Power Supply for Industrial Plants and Large Equipment
Power distribution in steel mills, machining workshops, and chemical plants shares common characteristics: high current, long distances, and reliance on cable trays or conduits. For a 200kW motor located 150 meters from the distribution room, copper cables would require approximately 3×185mm², while aluminum cables would need to be upgraded to 3×240mm². Although aluminum cables have a larger cross-sectional area, their overall purchase price is still nearly half that of copper cables.

More importantly, industrial environments often involve vibration and slightly corrosive gases. Modern aluminum alloy cables (such as AA-8000 series aluminum alloys) are much more flexible than pure aluminum, and are less prone to core breakage under repeated bending. Furthermore, aluminum cables do not experience stress corrosion cracking like copper in certain environments, making them a preferred choice for certain areas in chemical workshops.

Real-world example: A die-casting factory for automotive parts, where the ambient temperature consistently exceeds 40℃, has over a dozen aluminum cables laid side-by-side on steel cable trays in the workshop ceiling. In eight years, there has not been a single power outage caused by the cables themselves.

III. New Energy Photovoltaic and Wind Power Generation

You might not realize it, but the total length of DC-side cables in a 100MW photovoltaic power station can exceed 300 kilometers. If all of these were copper cables, the cable cost alone could account for 8%-10% of the total investment. Therefore, the photovoltaic industry has long used aluminum cables extensively—especially for the DC trunk line from the combiner box to the inverter, and the AC-side cables from the inverter to the step-up transformer.

Specific usage: For flexibility and weather resistance, copper cables are still mostly used from the strings within the photovoltaic field to the combiner box; however, from the combiner box to the centralized inverter (often hundreds of meters), photovoltaic-specific aluminum alloy cables are used directly. These are not only cheaper but also UV-resistant, ozone-resistant, and adaptable to temperature differences from -40℃ to 90℃.

The same applies to wind power generation: A 5MW wind turbine with a tower height of 120 meters, if using copper cables for the power cables inside the tower, could weigh over 4 tons, placing a burden on the tower structure and hoisting. Replacing them with aluminum alloy cables reduces the weight to around 2 tons. Many onshore and offshore wind turbines have now switched to aluminum cable solutions for their main power cables.

IV. Municipal Streetlights and Traffic Lighting
Streetlight power supply on urban main roads has a characteristic: long lines but low loads—a single streetlight cable might support 60 lights over a 2-kilometer stretch, each consuming only 250W. In this situation, voltage drop is often the primary concern, not current carrying capacity. Aluminum cables, because their cross-sectional area is easily increased (with minimal cost increase), offer a more economical solution to the voltage drop problem.

For example: for a 2-kilometer power supply distance and a 15kW load, copper cables would require 50mm² to meet the voltage drop requirements; aluminum cables, however, can use 95mm², resulting in a lower total material cost. Furthermore, since most streetlight lines are directly buried or laid in conduits, with low bending requirements, the disadvantages of aluminum cables are largely unnoticed.

In recent years, aluminum core YJV or aluminum core VV cables have been widely adopted for main roads in new urban areas, expressways around airports, and roads within industrial parks across many cities nationwide.

V. Temporary Power Projects and Rental Market
For temporary power supply at construction sites, large-scale events, and emergency power access—aluminum cables are almost standard equipment in these scenarios. Why? Because cables frequently need to be laid, moved, and even damaged by excavators. Aluminum cables have low procurement costs, and losses or damage are less distressing; moreover, they are lightweight, allowing two people to lay several hundred meters a day, and tight-schedule temporary power projects cannot afford to wait for heavy equipment to arrive.

Experienced temporary power rental companies will stock two specifications: aluminum cables for use between the main power supply and secondary distribution boxes, and copper cables only for connections from the final distribution box to specific equipment. This satisfies safety requirements, controls rental prices, and is acceptable to customers.

Where should aluminum cables be "absolutely not used"?

Clearly explaining the main uses and outlining the prohibitions demonstrates responsibility.

Fire protection wiring: Fire-resistant cables are required to maintain power supply for 90-180 minutes under a 950℃ flame. Aluminum cables experience a faster decline in mechanical strength at high temperatures than copper cables. Therefore, regulations explicitly require the use of copper cables for main power lines of fire pumps, smoke exhaust fans, emergency lighting, and other fire protection equipment.

In environments with severe movement or vibration: Crane conductor rails, elevator traveling cables, and port lifting equipment cables—where frequent bending, dragging, and twisting are required—the fatigue life of aluminum cables is far shorter than that of finely stranded copper cables.

In particularly humid or acid/alkali environments: While the oxide film of aluminum is stable in dry environments, the risk of electrochemical corrosion increases significantly in long-term humid or acid/alkali vapor environments if there are minor defects in the jointing process.

In summary, the main applications of aluminum cables are: large cross-section, long distance, medium load, and fixed installation in power distribution backbone scenarios, especially suitable for cost-sensitive projects, projects with limited construction conditions, or projects with weight requirements. Essentially, it is an engineering solution that "trades economic efficiency and lightweighting by appropriately increasing the cross-sectional area."

Get three key points right: choose the right aluminum alloy material (don't use the old-fashioned pure aluminum hard conductor), use copper-aluminum transition terminals, and tighten according to torque requirements and retighten regularly—aluminum cables are reliable enough and shouldn't be hindered by the prejudice of welding them in place.