Since the Fiber Optic Association published an item in its July 2011 newsletter about weighing copper cable to help determine if its conductors are copper or aluminum, the association has gotten a number of suggestions from professionals in the industry about that and other methods of counterfeit detection.
UPDATE (7/27): I have learned that most of the comments/tips provided to the FOA, and summarized here, came from James Mitchell, who operates a website called helpmecableguy.
Among the comments are the following.
1) Some cable brands include a plastic spool in the box, which adds 2 to 4 pounds to the box. And some generic cable brands can weigh as much as 25 to 30 pounds for bulk Cat 5e UTP. These differences may make it more difficult to detect a counterfeit, because even if lighter aluminum conductors are used the overall weight of the box could be close to that of a legit, copper-conductor cable.
2) Look for the holographic UL sticker (although it's also noted that holographic stickers are sometimes found on counterfeit CDs and DVDs).
3) From a street vendor in China (no kidding): Cut the wires into small sections and try picking them up with a magnet.
4) The newsletter update also expresses the importance of flammability ratings being genuine, in addition to the cable's performance characteristics.
You can read the updated FOA July 2011 newsletter here; it includes more detailed comments than those summarized in this post.
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4 comments:
I've posted an example of the UL Holographic sticker vs a "stamped" version on two recent tweets:
http://bit.ly/p84Nr4
http://bit.ly/pFX7lW
James D Mitchell
"HelpMeCableGuy"
Neither copper nor aluminum are ferous. There is an effect called inductive coupling that is more pronounced with aluminum, where a magnet will slide slowly across a sheet or tube angled to steep enough to overcome friction. The inductive coupling causes the accelleration of the magnet to be reduced. I am not aware of any effect from a magnet on small chunks of non ferous wire.
It would be useful if you provide an actual test and a series of results and not just a source of some guy in China.
Copper and aluminum wire (and mixtures) will have a different resistance value per 1,000 ft by gauge. Measure the wire to see the resistance. for instance, copper wire has a resistance of: Wire Gauge Resistance per foot
4 .000292
6 .000465
8 .000739
10 .00118
12 .00187
14 .00297
16 .00473
18 .00751
20 .0119
22 .0190
24 .0302
26 .0480
28 .0764
Aluminum is not quite twice this value. A mixture will be some where between these. The closer to copper values, the better the fake. At some point a fake could be so good, it will not make a difference in operation. other factors such as flame travel would be very hard to measure in the field.
Ok course in the US, you cannot use a non approved electrical product legally!
on china made cables
look for differences between your regular brand and the suspected imitation. most fakes are not 100% alike. most China made fakes have one of the following problems.
- poorer quality printing. colours on boxes differ, identical serial numbers, but beware fakes are gettingbetter by the day.
(I have seen installers in China bringing home used cable boxes, its anybody guess what they do with them)
- poorer resolution printing on cables>> more spacing between dots in each letter
- some fakes uses telephone cables designs and still come with pulling yarn which has been made obsolete in most branded cables.
- does your regular brand have striped orange / blue / brown / green for their white wire? Some don't and most China made cables do come with the striped coloured wires.
- for pure copper fakes, a fluke test is not going to help you. Some fakes may fail Cat 6, but almost all Chinese manufacturers can pass Cat 5e, esp when used with genuine RJ45 jacks and patchpanels.
for the CCA imitation,
- weight and resistivity are obviously good indicators.
- copper wires are more flexible, aluminium are more brittle. Aluminium wires are also harder and more difficut to punch down.
- the best fakes are those that have pure copper for orange and green pairs ( for 100BaseT) and aluminium for brown and blue. don't be fooled if your 100BaseT network works well and the technician twill the green and orange wires to show you how flexible they are.
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