Advertisement

Advertisement

November Quiz With Correct Answers and Explanations

By Jim Hayes | Nov 15, 2011
shoes_sneakers_dreamstime_m_16714434.jpg
Web Exclusive Content

Advertisement

Advertisement

Advertisement

You're reading an older article from ELECTRICAL CONTRACTOR. Some content, such as code-related information, may be outdated. Visit our homepage to view the most up-to-date articles.

The cabling market appears to be flooded with cheap, poor quality and counterfeit cabling products. It takes a lot of knowledge and effort to keep from being defeated by these inferior and sometimes unsafe products. How well-armed are you for the battle? Answers and explanations are in red.

1. Never buy any cable unless it is marked with _________.
A. The manufacturer’s identification
B. The date of manufacture
C. The UL file number for indoor-rated cable
D. Contact information for checking all of the above yourself

One sure sign of counterfeit or poor quality cable is a “generic” box without information on the manufacturer.

2. A quick way to determine if a box of Category-rated unshielded twisted-pair (UTP) cable is made from the right kind of wire is to _________.
A. Look for a known manufacturer’s name on the box
B. Look for a UL file number on the cable
C. Strip a portion of the jacket and look at one pair of wires
D. Weigh the box to see if it’s underweight

Counterfeit UTP cable made from aluminum weighs about 1415 pounds per 1,000-foot box while copper cable weighs more than 20 pounds.

3. If copper pairs keep breaking when being punched down on a jack or patch panel, a possible cause is _________.
A. The cable is counterfeit, made from aluminum, not copper
B. A bad punchdown tool
C. The cable jacket is too thin
D. The installer is just clumsy

Counterfeit UTP made from aluminum is much more brittle than copper and often breaks on punchdowns. Unfortunately, breaks are sometimes hidden under insulation and may only be found when testing.

4. Patchcords are too short to be a problem in either copper or fiber networks, so it’s safe to just buy the cheapest ones.
True
False

Patchcords can cause major problems in both fiber and copper systems. In fiber it’s mainly loss and reflectance, but with copper it may affect almost every spec of the system and bring performance levels down to lower cable grades.

5. To ensure the quality of fiber patchcords, _________.
A. Buy only from reputable manufacturers or distributors
B. Look for original QC labels
C. Test every one of them yourself
D. Any or all of the above

While testing every patchcord can be expensive, it’s the only certain way to judge quality. But buying from reputable manufacturers and making certain QC labels are not just copies are good practices also.

6. Performance is important in indoor UTP or fiber optic cables, but one must also worry about flame retardance of the jacket in suspect cables.
True
False

Counterfeit cables may have plastic insulation and jackets made from plastics that do not meet specifications for flame retardance.

7. A fiber optic cable is hard to strip and breaks easily during splicing and termination. One should _________.
A. Check the date of manufacture on the cable or reel to see if it is old
B. Assume the tech installing it is just clumsy and keep trying
C. Get new tools and try again
D. Heat it with a heat gun to make it easier to strip

Some fiber optic cable has been sold that is old and has been improperly stored. The fibers may be brittle and hard to handle.

8. Large spools of fiber optic cable should be inspected when received to check _________.
A. Cable type and construction
B. Number of fibers
C. Continuity of all fibers and attenuation on a sample number
D. All of the above

Customers have been sold cable that did not meet specifications and/or was inappropriate for the installation. It’s important to verify that the cable delivered is the cable that was ordered.

9. If you suspect a cable is counterfeit, you can check the UL file number on the UL website.
True
False

The UL website allows you to check UL File Numbers printed on cables to check their validity.

10. One surefire way to identify counterfeit or poor-quality cable is the _________.
A. Box or packaging
B. QC stickers or stamps
C. Price
D. None of the above

Unfortunately none of these work. Often counterfeit cable has carefully copied logos and designs from legitimate manufacturers, official looking QC stickers and is even expensive!


HAYES is a VDV writer and educator and the president of The Fiber Optic Association. Find him at www.jimhayes.com.

About The Author

HAYES is a VDV writer and educator and the president of the Fiber Optic Association. Find him at www.JimHayes.com.

Advertisement

Advertisement

Advertisement

Advertisement

featured Video

;

New from Lutron: Lumaris tape light

Want an easier way to do tunable white tape light?

Advertisement

Related Articles

Advertisement