Two reasons…

1. CCA is a cheap, problematic product that gives the false impression of cost savings.

2. CCA can be a fire hazard if used for PoE.

CCA has issues with longevity, signal integrity and even safety. The installation process of a cable is always going to be much more expensive than the cable itself, so cheaping out for not much difference at all is just not worth it.

In addition to the good advice everyone else has given, I have had problems terminating CCA cable. I get the cable in the connector and crimp it with my (relatively cheap) crimping tool and it all looks great. Then I hook up the cable tester and it fails all of the tests so I cut the ends off (because they both look to be correct) and try again. I spent over an hour trying to terminate one cable a few months back. I thought it was the crimping tool at first. I had ordered some solid aluminum cable because I need PoE for an access point. When it came, every single cable I made with it terminated correctly first time. That was when I realized how bad the CCA was and tossed it in the trash.

One additional negative (to the already numerous comments against CCA) is the general frailty of the cable itself.

It is fairly easy to break one of the conductors inside the cable, if it gets kinked/snagged while pulling the cable. Copper is much more forgiving.

Also, for those who foolishly crimped plugs onto the ends of the cables, they probably learned fairly quickly that the terminations failed at a higher than normal rate compared to copper cables. I suspect that the aluminum, being more brittle than copper, is probably cracking inside the connector either during the crimping process, or due to strain on the cable at the connector.

CVA is dogshit. Don’t do this to yourself. You will regret it.

I had a customer with 200 odd CCA cables at a site next to the sea. The terminations would oxidise and stop working all the time. Ended up injecting silicon grease on all the ends.

I wouldn’t go near it.

the cladding temporarily gets rid of dissimilar metals issues

The cabling in your wall is, for all intents and purposes, never going to be messed with again and lives in a place that isn’t accessible. Ignoring any fire or heat related considerations, aluminum and copper expand and contract at different rates. Eventually that cable will fail as the heat from the extra power for PoE will cause deterioration. You’ll just replace the patch cable at the end when that happens, but the main run is a much bigger deal to replace. Don’t save a dollar now to spend it many times over later.

I thought that stuff was a con? Seems its been more widly accepted now.

the labor cost if wireing your house is 10x the cost of the cable. Saving 20% in cablecost has a minimal effect on the total cost. CCA is only attrative if you have a fixed price project and have no concern about the drawbacks of CCA.

Aluminum has higher resistance than copper and comes with other issues. Why waste more of the power as heat? Just say NO!

OP: 24 people telling you CCA is garbage. Now 25. Do you need any more or can we put this one to bed again?

Srsly.

I do this as a job. Network engineer here.

If I find CCA, I replace it. If I am told not to replace it, I refuse to do the job (I am no longer told not to replace it, and of course, I don’t think we have any left in the company at any location.)

I have found boxes of CCA when I went looking for some cable in one of our warehouses. They were sent to recycle.

CCA is not suitable for pretty much any purpose as far as I am concerned.

CCA exists because it is far cheaper to make and sell, not because of the process to coat aluminum in a thin layer of copper, but because aluminum is far cheaper than copper. It’s a cost savings for the manufacturer, not the consumer. Any savings realized by the consumer is incidental, and generally made up for by the poorer performance of the CCA.

As mentioned by many others, the physical expansion and contraction of the aluminum is not even remotely similar to that of copper, use of CCA for PoE is not advised, even by some manufacturers of it, and fellow network field service techs and engineers will simply not leave the answer to the question that no one but procurement department accountants asked in any location that they are responsible for. Wall fires are kinda hard to spot, you might agree, and CCA is like mice in your walls, as where you find one, you find ten thousand.

Yes, CCA is cheaper, but you give up many things for that reduction in price. CCA gets hotter, CCA doesn’t work as well for integrity of data transfer over an equal distance than copper, CCA requires additional work to prevent oxidization and increase in resistance over time, which itself adds to the heat problem, and if the manufacturer cheaps out by producing a proper quality cable, what else are they cheaping out on (I have encountered some of the most brittle cable sheathing and wire cladding I have ever seen on CCA, like the stuff was made, then exposed to UV for far too long, and that was a problem when the protection of the sheathing was lost, which caused wires in the cable to come into contact with each other, requiring replacement when it would no longer do the one job it was put in place for.)

CCA. Not even once.