Copper Wire Vs. Copper Clad Aluminum Wire - Wire Warnings

A pure copper cable and a CCA cable were measured and proved to be "full-spec" 4-gauge as determined by the American Wire Gauge chart. The second pure copper cable is sold as 4-gauge but is about 10 percent under spec in strand count and diameter. It's also less expensive than the full-spec copper, so that may be an indication for the buyer to pay attention.

Each cable was exactly 20' in length and the heating test involved passing 100A of current through it for a 30-minute duration. This is a severe condition but not impossible to duplicate in large systems. The ambient temperature and the start temp of each cable was 76F (see measurements below).

Conclusion
At this point you might be thinking that CCA wire is bad and shouldn't be used, but that's not the case. We've done extensive testing on CCA wire for several manufacturers and our results show that it can work very well for all but the highest current applications. Because of the additional resistance you simply can't substitute the same gauge CCA wire for the traditional gauge copper wire. Our strong recommendation would be to simply use one gauge larger size of the CCA cable than the copper cable.

That being said, if you compensate for the increased resistance in the CCA cable by going to the next larger gauge size, you'll probably end up with equal or maybe even less resistance than the smaller gauge pure copper. But along with an increase in cable size comes an increase in price. This could mean little difference in bottom line prices between comparable copper and a +1-gauge in CCA, so be aware of whatyou're buying.