Aluminum alloy cable is not a cheaper copper cable. It is a different conductor that does the same job, and it saves money only when it is sized, terminated and specified as aluminum from the start. A good aluminum alloy cable manufacturer will tell you the same, and the trouble, when there is any, shows up at the connections rather than in the cable.
The basic trade
Aluminum conducts electricity less well than copper, roughly 60 percent as well for common conductor grades. To carry the same current you need a larger conductor cross-section. The upside is that aluminum is far lighter, which makes it easier to pull, easier to hang and cheaper to ship, so even with a larger size the cable can win on cost and handling. For large feeders, service entrances and long runs, this trade is often worthwhile.
Why the alloy matters
Old-style pure aluminum conductors had a bad reputation because they tended to creep, which means they slowly deform under the pressure of a termination, and the connection loosens. Modern aluminum alloy conductors, such as the 8000 series types used in many cables, were developed to behave better, with improved creep resistance and flexibility. That is the whole point of choosing an alloy cable instead of an older aluminum design.
Some manufacturers add small amounts of rare earth elements, which is what a rare earth aluminum alloy cable refers to. The goal is usually a better balance between conductivity, strength and bending behavior. These claims are only as good as the test data behind them, so ask for conductor resistance results, elongation and bending test reports, and the alloy composition the manufacturer uses.
Terminations are the real risk
Aluminum forms a thin oxide layer quickly, and that layer is a poor conductor. It also expands and contracts more than copper when it heats and cools. Use connectors that are rated for aluminum, normally marked AL/CU or AL, apply an oxide-inhibiting compound where the method calls for it, and tighten to the specified torque. Most problems attributed to aluminum cable are really lugs that were never meant for it, or screws tightened without a torque wrench.
Standards and the ACWU90 question
If your project is in Canada or follows Canadian practice, you will hear about ACWU90, a type of aluminum alloy cable used for building and utility installations. When you look for a China ACWU90 cable manufacturer, ask which standard the cable was tested to, request the certification, and check that the label, conductor size and voltage rating on the cable match your project. Never rely on a verbal statement that a cable “meets code”. Ask for the document.
Also think about the environment. Cable that runs underground, in conduit, outdoors or in damp conditions needs the right insulation and jacket, and some types are rated only for certain uses. The cable type that works for a dry indoor feeder may not be suitable where water is present.
A short checklist before you buy
Compare cable size for the same ampacity, not price per meter. Check the conductor alloy and the standard, the insulation and jacket rating, the type and quality of the connectors you will use, and the packaging and reel length, which affects waste on site. And if you are weighing a China aluminum alloy cable supplier against a local one, ask for a sample length and test it yourself or through a third party.
Also agree on the reel or coil length. Cutting a 500 meter reel into odd pieces on site creates waste, so match the delivery lengths to your run lengths where you can, and ask how the ends are sealed against moisture. It sounds minor, but it affects both cost and the quality of the cable you install.
Used with the right size and the right lugs, aluminum alloy cable is a perfectly sound choice, which is why it has been in service for decades. The failures come from treating it like copper.Aluminum alloy and rare earth aluminum alloy cables are on the Tengyuetong website:https://www.gdtytcable.com