Friday, June 29, 2012

Outdoor Aerial Wire and Cable Installation - Moving Reel Method

Customers purchasing our many different types of outdoor wire and cable commonly ask how to lash cable to a messenger wire. One of the most common ways to do this is by using the moving reel method.


This method is used when reel carrying vehicles can drive most of the route. This method may be used when placing cable on a suspended strand or to an existing lashed cable and strand. Check out this cool lashing machine in action!


Each time a pole is reached the pulling stops. The cable guide (just in front of the lasher), and lasher get disconnected and moved past the pole. An expansion loop to the messenger is formed as temperature changes contracts the steel more then cables. Example below.


Before you get started let's go over some precautions.

* All personnel must be familiar with OSHA Occupational Safety and Hazard Act regulations.
* Follow the National Electrical Safety Code (NESC) for all installations.
* Cables installed near high voltage lines should be grounded.
* Cables that contain a corrugated steel tape should be grounded.
* The steel messenger shall be grounded.
* Make allowances for changing sag of the steel messenger wire in various weather conditions. Steel  messenger wire will expand and increase sag in warm weather.
* The steel messenger should be kept on one side of the poles (avoid zigzagging from one side of the pole to the other).
* Carefully inspect reels for imperfections such as broken flanges, cable crossovers, nails or anything that may cause damage as it is payed out.
* Follow the cable bend radius. Coax, phone and fiber wire and cable will differ.
* Never during the install should cable experience sags, bends and twist. A reduction in the cables transmission characteristics may not reveal itself till after installation.
* Do a pre-survey for splice locations, slack locations, cable storage requirements and possible obstructions like trees, roadways etc.
* You may want to consult an outside plant engineer.

As you can tell it sounds easy but lots of precautions do go into an installation of this type. I can hear my mother now, "Don't forget to put your helmet on!"

Thanks to Prysmian, OCC and Commscope.

"By Mercy Salinas"

    

Friday, June 22, 2012

Fidel Castro and Hugo Chavez Installing Fiber Optic Cable?

"Secrets are over. ... We are facing the most powerful weapon that has ever existed, which is communication," Castro told Mexican daily La Jornada in an August 2010 interview in which he hailed the coming cable.



It has been almost 2 years and unfortunately the Cuban people are still waiting for faster internet. The current network is still in the 90’s. At 3-5 kilobytes per second dial up transfer speeds a 500 megabyte video file would take between 28 and 46 hours from Itunes. People are swapping digital pictures on memory sticks rather than sending it as an e-mail attachment, what a nightmare.

The cable was strung from Venezuela with the help of key ally Hugo Chavez.



Government officials said from the start that the bandwidth boon would be prioritized for hospitals, universities and other usage deemed in service of the common good; the legions of Cubans with little or no access to the Internet from their homes would have to wait.

Why has this 70 million dollar project stalled? The project was carried out by Alcatel-Lucent of France for the state telecommunications companies of Venezuela and Cuba. A senior French official told the Associated Press that Alcatel had upheld its part of the contract and whatever problems exist must be on land with the network it was meant to be attached to. "The cable must be connected to something or it won't work," said the official, who also spoke on condition of anonymity because he was not authorized to discuss the politically sensitive project.

Jorge Arreaza, Venezuela’s science and technology minister, said that “a few months ago we signed all the remaining protocols, all the necessary security measures with the Cuban government. It’s absolutely operational. It will depend on the Cuban government what it uses it for. Of course that’s their sovereign matter, but we know that the undersea cable is in full operation,’’ Arreaza told reporters.

Its been over a year since the system was supposed to have gone online, Cuba’s government has not recently mentioned the cable. The Internet on the island remains the slowest in the Western Hemisphere. Perhaps Mr. Castro is not prepare to unleash the most powerful weapon that has ever existed.

Comment below. Thanks!

Friday, June 15, 2012

What the heck is LSZH Wire and Cable?

So you've been doing wiring for some time now and you come across a job walk that specifies the installation of LSZH or maybe you need to match some cable at your location that is LSZH specified. Lets check out what is LSZH, where to install it and pros and cons.

LSZH stands for Low Smoke Zero Halogen. The cable jacket and insulation is made with some very special materials. In case this type of cable is ever involved in a fire very little smoke is produced making this cable an excellent choice for confined places with lots of people.

I know the LS part is easily understood but what about the ZH? The zero halogen, what is that? Halogens are elements such as bromine, chlorine and fluorine. Halogens are very highly reactive and hurt people and animals. PVC wire and cable has a huge amount of halogens in it. The C stands for chloride and typically this cable on average contains 29% by weight. Teflon, FPE and PTFE contain up to 76% of fluorine. Halogens in LSZH materials are under 1%

Another concern is when cable is burned and toxic gases are released into the air they can also be harmful when mixed with water. So when that sprinkler system turns on you've now created toxic acids.

The number one cause of death related to fires is smoke inhalation. An estimated 70% of fire deaths are a result of smoke inhalation rather than burns. Smoke Inhalation occurs when products of combustion are breath in during a fire. Damages to the body are by simple asphyxiation (lack of oxygen), chemical irritation, chemical asphyxiation or a combination of all these.

Now that you have a quick understanding of LSZH what are the Pros and Cons of the cable?

PRO: LSZH produces less smoke when burned allowing for more time to exit.

CON: LSZH is more susceptible to jacket cracking. Special lubricants have been made to minimize damage during installation.

PRO: Because little or no halogen gas is released less damage to the respiratory is done and less corrosion damage is done to equipment near the fire.

CON: LSZH jacket has a high filler content, around 50% to provide the required flame and smoke performance. This results in a lower mechanical, chemical resistance, water absorption and electrical properties then non LSZH compounds.

PRO: The jacket of LSZH cable has a lower coefficient of friction making installation easier.

CON: The current generation of LSZH cables has not yet established a proven history of long time performance.

In one of our YOUTUBE videos a LSZH fiber cable is shown. Its hard to tell the difference just looking at it but off camera I did notice once stripped that the jacket buckled and cracked when flexing it.



Questions? Comment below!

"By Mercy Salinas"

Friday, June 1, 2012

Mine Safety and Health Administration Approved Fiber Cable

Today's mining engineers are heavily relied on to plan mining operations. From designing underground and surface mines to equipment and even supervising the operators who run it.


Because of the high demands from not only the job site but from the Mine Safety and Health Administration the importance of a MSHA approved cable is greater then ever.

Discount-Low-Voltage.com offers a MSHA approved cable from AFL Telecommunications. The outer jacket is manufactured with a UV stabilizer for protection against exposure to the sun plus anti-fungus protection for use in underground applications.


This Fiber cable is also water blocked and meets water penetration requirement of GR-20-CORE. (This helps ensure that any damage to the cable is restricted to a repairable length of several meters.) Includes a riser rating so cable can be used in all environments, general inside plant and outside plant. Tested to meet or exceed EIA/TIA 568-A, GR-409-CORE and ICEA-S-104-696. Compliant to directive 202/95/EC RoSH.

Cable is cut to length to whatever your requirement might be, 625 feet or 8,750 feet and a continuous run is no problem. You may also consider our preterminated option so you can provide a plug and play solution at the mine.

Questions? You may contact Mercy Salinas at 888-797-3697 extension 232.

"By Mercy Salinas"