Copper remains a primary carrier for integrated building systems, but fiber optic cabling is assuming an increasingly important role in data, telephone, access controls, security cameras, fire and security alarms, sensors, and other signaling-dependent systems.
“With fiber optic cabling, we may have to reboot the entire concept of low-voltage structured wiring,” said Frank Bisbee, editor of online electronic magazine, Heard on the Street, (www.wireville.com). “That puts the integrated systems contractor in an enviable position for sustainable growth without regard for the state of the economy. New applications and technology will be emerging in our world in ways that we haven’t considered yet.”
Kitco Fiber Optics Design Engineer Donald Stone said fiber optics is growing around 20 percent per year.
“Most telecommunications closets today are fiber optics, and the costs of fiber optics continues to decrease with the increase in demand for bandwidth,” he said.
Rick Salvas, national accounts broadband manager for Ripley, said that most existing video surveillance systems do not use fiber optic cable. However, as the upfront costs associated with purchasing and installing fiber come down—such as the availability of prefabricated fiber cables with connectors already at both ends—newer networks are incorporating fiber.
“Some of the larger or campus-size installations use fiber to connect two or more distinct networks, such as connecting across town, where devices are far from a data center,” he said. “In this scenario, simple media converters are often used, and the increased bandwidth afforded by fiber allows for multiplexing of several networks. Facilities that have the need for many cameras frequently elect to go with fiber because of the increased bandwidth fiber provides. This, combined with the high-definition video equipment, overwhelms traditional Ethernet or coaxial networks.”
Fiber is also used as a sensing means for surveillance systems covering large areas with lengthy perimeters.
“In such installations,” Salvas said, “fiber is strung around the perimeter, typically on a fence. Sophisticated equipment then is used to monitor the signal passed through the cable. Any disturbances or breaks in the cable cause fluctuations in the signal, which the monitoring equipment can sense and locate. Some systems can pinpoint the area of disturbance to within one meter of the actual point of entry.”
Most electricians easily adapt to low-voltage copper installation and maintenance work, but terminating fiber cable requires special training and tools. Specific tools needed depend on termination procedure used.
Kitco’s Stone summarized basic fiber termination procedures:
• Epoxy method—Fiber optic connectors are secured to the fiber optic cable using a two-part epoxy cured in an epoxy oven.
• Preloaded adhesive method—Fiber optic connectors are preloaded with an adhesive that must be softened using a special oven. Once the adhesive is at the correct temperature, the optical fiber is inserted into the optic connector and is allowed to cool down, solidifying the adhesive.
• Anaerobic method—Fiber optic connectors are installed using two chemicals that rapidly react when they come in contact with each other. One of these chemicals is an adhesive, and the other is an accelerator or primer.
• Crimp and cleave method—special fiber optic connectors that do not require any type of epoxy or adhesive are used; the optical fiber is clamped within the connector, and fiber protruding from the end-face is cleaved off.
• Prepolished method—Special fiber optic connectors have a fiber stub bonded within the connector. The fiber stub at the connector end-face is factory-polished and requires no field polishing. The optical fiber from the fiber optic cable is cleaved and installed into the rear of the connector. The fiber is secured with special clamp (cam) inside the connector and crimped to the fiber optic cable jacket.
• Fusion splice-on connector method—This fiber optic connector has the optical fiber epoxied onto an optical cable and is prepolished. The opposite end is a bare fiber stub that is fusion-spliced to the fiber optic connector.
No significant changes in fiber tools have occurred since the last Cool Tools report on the topic.
“However,” Salvas said, “fiber tool manufacturers are being encouraged to develop tool designs that require fewer tools to perform the complete fiber preparation. The ultimate solution is to have fewer tools to save preparation time and, therefore, save installation labor as the end result.”
Essential tools vary with the type of job and include the following:
• Jacket stripper and fiber stripper (some tools do both)
• Kevlar cutter
• Black work station mat
• Fiber scrap receptacle
• Cleaning wipes or swabs
• Lapping film
• Polishing disc
• Neoprene pad (base for polishing)
• 200x power microscope
• Curing oven or crimp tool (depending on connector type)
• Visual fault finder or continuity tester
Kitco’s Stone said prepolished connectors continue to evolve, making it easier for the technician to install them.
“There have also been improvements in the splice-on style connectors as well,” he said, citing connectors that are fusion-spliced onto the fiber using a connector with a small bare fiber pigtail.
Training and skill are necessary to make proper fiber connections.
Kitco, Ripley, other manufacturers and independent fiber organizations offer training and certification programs. There are different levels of training offered, including Certified Fiber Optics Installer (CFOI) and Certified Fiber Optics Technician (CFOT).
“The skill set required to connect fiber is completely different than that used in copper terminations,” Stone said. “Technicians must understand the different types of optical fibers that they will be terminating and the type of connection process to use based on the application. Fiber optic terminations require continuous practice as this is a very perishable skill set. Once the fiber technician is trained, they must maintain their termination and polishing skills in order to be effective.”
Poorly made fiber connections can be expensive. Performing improper polishing procedures, using the wrong grade of polishing papers, under-polishing the connector end-face, overpolishing the connector end-face, or bad scribing techniques can result in broken optical glass, chips, pits, scratches and other problems, Stone said.
Ripley’s Salvas said a poorly trained installer can cost a company thousands of dollars with just one inferior installation.
“Fiber termination,” he said, “requires specialized skills for proper cable handling: the need to consider cable-bending radius and maximum tensile strength, cable preparation, as well as maintaining a contamination-free work environment.
“A fiber cable improperly stripped or an improperly cleaned fiber end can shut down an entire network. In-depth studies have revealed that contaminated connectors and shoddy polishing of the ferrule was the number one root cause of network failure—a direct correlation to properly instructed techniques.
“The advent of prepolished connectors and prefabricated fiber cable assemblies have certainly made terminations easier and less costly, but only by using high quality specialized fiber tools and approved terminating procedures will fiber terminations be successful in security, alarm or building control system installations. Quality installations will be further guaranteed by staying in close communications with manufacturers of quality fiber tool products and staying on top of the latest tool developments and enhancements,” Salvas said.