An Infrastructure Advisory Note (IAN) from the Fibreoptic Industry Association (FIA) provides detail on the practical effects of installing cable with copper-clad aluminum conductors in premises networks. The IAN is entitled "The Impact of Copper Clad Aluminum (And Steel) Conductors Within Balanced Pair Cables (Intended For Use Within Implementations Of Generic Cabling)." The FIA is a UK-based organization that says its aims and objectives include "to promote high standards of service within the fibreoptic industry and to represent its members at a national and international level." The group adds, "The membership profile of the FIA comprises manufacturer, suppliers, installers and users."
The nine-page IAN includes a section that provides information on the European, North American and international standards specifying twisted-pair cable. It then explains that all these cable specifications "require the conductors to be of solid copper (whether or not they are stranded)." In other words, twisted-pair cables with copper-clad aluminum or copper-clad steel conductors are, by definition, non-compliant with CENELEC, TIA and ISO/IEC standards.
The paper also gets into detail on the performance maladies that users will face if these cable types end up in their networks. It describes electrical-performance characteristics that suffer when copper-clad aluminum conductors are used. These characteristics include DC resistance, insertion loss/attenuation, return loss, near-end crosstalk and others. The paper also explains the negative effects of using this cable type in systems employing Power over Ethernet, the impact of flexing and bending a copper-clad aluminum cable, and the impact of oxidation.
In addressing the commercial implications of using copper-clad aluminum conductor cable, the FIA paper says, "If a user specifies the use of CCA cables, then they cannot simultaneously demand Category-based performance for the cable or request that the installed cabling meets a given Class against ISO/IEC 11801 or EN 50173-1 without a significant risk of failure during acceptance testing."
You can read or download the paper directly from the FIA here.
