Tips to Identify Copper Clad Aluminium (CCA) Cables

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Tips to Identify Copper Clad Aluminium (CCA)
Cables-Mark Mullins
www.flukenetworks.com 2006-2017 Fluke
Corporation
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Tips to Identify Copper Clad Aluminium (CCA)
Cables
So you came across some Category 6 cable
available online for practically half what you've
been paying for that brand name. It claims
TIA-568-C compliance, includes the UL listing
mark and even has a ETL verification legend
printed right on the cable. Before you get too
excited, you might want to make sure that cable
isn't made with copper clad aluminum (CCA). Less
expensive than using solid copper, cables made
with CCA conductors are simply not worth the
risk. Not only are they non-standards compliant,
but they often do not have a valid UL safety
listing per the National Electric Code(NEC)
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Tips to Identify Copper Clad Aluminium (CCA)
Cables
A Hot Balancing Act
While the biggest concerns surrounding
counterfeit CCA cables should be the safety risk,
these types of cables can significantly reduce
network performance--especially with the
increasing use of PoE to power everything from
phones, laptops and Wi-Fi access points, to video
surveillance cameras, digital displays and even
LED lights. The resistance of an aluminum cable
is about 55 greater than for a copper cable of
the same diameter. This means more heat generated
within CCA cable and lower voltage available at
the end device. So not only is there a chance
that the end device won't have the power it
needs, but heat rise within cable bundles also
leads to increased insertion loss since signals
attenuate more in proportion to temperature.
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Tips to Identify Copper Clad Aluminium (CCA)
Cables
A Hot Balancing Act
It's not just the heat that causes problems.
When power is delivered, it is split between each
conductor of a pair. If the resistance of the two
conductors is equal, the DC Resistance Unbalance
(the difference in resistance between two
conductors) is at zero, current is split evenly,
and common-mode current is achieved. But this is
rarely the case with CCA cables. While good
workmanship and consistency in termination is
important to preventing DC Resistance Unbalance,
the variations in the diameter, concentricity
(roundness), contour and smoothness found in CCA
cable causes a higher risk for unbalance that
distort the waveform of Ethernet data signals.
The result is greater bit errors, retransmits and
even non-functioning data links.
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Tips to Identify Copper Clad Aluminium (CCA)
Cables
That's Why You Test It
There are a few tips for identifying CCA cables
that include scraping the conductor to reveal the
silver colored aluminum beneath the copper
cladding and even weighing the box since aluminum
is lighter than copper. Cutting cable and
scraping conductors isn't exactly the preferred
method if the cable is already installed and the
customer isn't pleased with the performance
(especially if CCA cable turns out NOT to be the
problem). And there have been reports of ballast
being placed in cable boxes or counterfeiters
using heavier versions of CCA to match the weight
of real copper cabling.
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Tips to Identify Copper Clad Aluminium (CCA)
Cables
That's Why You Test It
Then there's testing. Not only is it important
for verifying standards compliance and
application assurance, but it also might help
detect CCA cable. Fluke Network's DSX-5000
CableAnalyzer has the ability to test for DC
Resistance Unbalance, verifying that both
conductors in a pair have equal resistance to
enable common-mode current and effectively
support PoE while avoiding distortion of the data
signals transmitting on the same pair. When
testing a CCA cable, Fluke Networks found the DC
Resistance Unbalance to be clearly out of
specification, and data suggests that CCA fails
DC Resistance Unbalance regardless of link
length. Besides, as the number of devices
simultaneously running gigabit Ethernet and PoE
continues to rise, and as the amount of power
delivered via PoE increases, field testing of DC
Resistance Unbalance becomes even more
important--for all cables. Click here to read
more about the importance of testing for DC
Resistance Unbalance in PoE applications.
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