Application note addresses copper-clad aluminum cable from testing perspective
Document from Fluke Networks describes the roles of DC resistance and resistance unbalance measurements.
An application note recently published by Fluke Networks discusses the challenges industry professionals currently face regarding copper-clad aluminum (CCA) cable. Addressing concerns in the United States and in Europe, the application note quotes CCCA executive director Frank Peri as well as Fibreoptic Industry Association (FIA) technical director Mike Gilmore, who address U.S. and European challenges, respectively.
“It’s not difficult to find these [CCA] products on the Internet through wholesalers and distributors,” Peri is quoted as saying. “We tend to find more of these on the west coast because Long Beach [California] is a huge port of entry.”
Gilmore added that in Europe, “The cables are generally sold through the electrical wholesaler market rather than the data market, so I only see them after a problem has been identified. Electrical contractors are now an obvious supplier for small data cabling tasks and they are very cost-driven. The wholesalers know this and react accordingly. On many occasions the install Is not tested using ‘industry standard’ test equipment, so the problems are not found out until too late.”
Testing is where Fluke Networks comes into the picture. The application note explains that the most simplistic method of ferreting out CCA cable—weighing the box because if it is lighter than it should be, that’s a telltale sign of aluminum’s presence—has quickly been countered by the CCA producers who simply add gravel or something similar to the box to increase its weight. Either way, once a cable is installed, identifying it as CCA can be an exercise in frustration. “Cable testing is another way to identify fake cable, but field testing these CCA cables to either ANSI/TIA or ISO/IEC might not catch the fact that they are CCA cables,” the application note cautions. “Testing to the ANSI/TIA-568-C.2 standard is deferred to ANSI/TIA-1152 Requirements for Field Test Instruments and Measurements for Balanced Twisted Pair Cabling,” it further explains, “where DC resistance is NOT REQUIRED [emphasis added] to be included in a field test. Even if TIA required DC resistance as a field test, it would not guarantee finding CCA cable.”
The note further explains that even simply requiring DC resistance a required field-test measurement is not foolproof because, “Practically speaking, the measurement uncertainty associated with length measurements would increase the probability of failing a link that is compliant.” Then it informs us, “Limited data from the field suggests that CCA cable fails DC resistance unbalance, regardless of length.”
The document concludes with information specific to Fluke Networks’ DSX-5000 tester, and how users of that tester can configure tests to, as much as possible, detect CCA cable once it is installed.