Quick-connect fiber-optic connectors slash installation labor, time and cost
By eliminating epoxies and perhaps polishing, quick-connect fiber-optic connectors provide a tight, secure and reliable interconnection to optical fiber in just one to five minutes
Lynn Haber
Quick-connect fiber-optic connectors have found favor with installers and end-users because these products prove easy to use, save costs and perform reliably. As a result, these connectors are rapidly replacing the older and time-tested connector technologies. Moreover, quick-connect fiber-optic connectors are helping to enhance the market image of optical fiber as an elementary and cost-effective technology--and to dispel its reputation as a scientific medium requiring special tools, equipment and skill to install.
At least five companies offer a variety of quick-connect fiber-optic connectors: 3M Telecom Systems Division in Austin, TX; AMP Inc. in Harrisburg, PA; Automatic Tool & Connector Co. in Union, NJ; Nordx/CDT in Montreal; and Siecor Corp. in Hickory, NC. Available for both singlemode and multimode fiber, the connectors come with a ceramic, stainless-steel or composite ferrule and are available with industry-standard ST and SC structures.
The goal of quick-connect technology is that the connector be able to achieve a fast, secure interconnection with fiber-optic cable. However, methods of achieving this goal vary. Whereas all vendors claim connection times of minutes--usually less than five minutes because epoxies are not used--some quick-connect products require polishing and others do not. For example, AMP`s LightCrimp and 3M`s CrimpLok products need polishing, but Nordx/CDT`s OptiMax, Siecor`s CamLite and UniCam products do not.
Automated Tool`s Terminator product line falls into a category of its own. Unlike the Nordx/CDT and Siecor offerings, which are shipped prepolished from the factory, Automated Tool officials declare that the company`s connectors achieve low loss with no factory polishing--and no field polishing, either.
According to Jim McGibney, president of Power Communication Services Inc. in Yonkers, NY, quick-connect fiber-optic connectors work dependently. "I can install them and not worry," he says. In fact, such product confidence governs the fiber-optic connector market.
McGibney reports that in the first half of this year, his company installed more than 4000 quick-connect connectors. Although he has used primarily AMP products for the last two years, he says that his company will also use quick-connect products from other companies, if so requested by the end-user.
No epoxy needed
In splicing most fiber-optic cables, technicians have had to rely on connectors that use an epoxy adhesive to hold the fiber in position within the ferrule. Epoxy forms a strong and long-lasting bond that barely degrades fiber performance. However, using epoxy incurs a high cost because time, labor and tools are needed to terminate a connector.
The epoxy must be prepared, placed in the connector ferrule and cured in an oven. Then the connector must be polished. Curing time takes as long as 20 minutes per connector, and this time does not include the time needed to warm up the curing oven. Ovens also need power, which is not always available at an installation site.
The greatest benefit of field-installable, quick-connect fiber-optic connectors is that they slash installation time by eliminating the need for epoxy adhesives. "It takes two minutes to use AMP quick-connect connectors, compared to 10 to 30 minutes to use an epoxy-based connector," contends Michael S. Peppler, AMP associate director of marketing for fiber-optic and broadband systems.
Not only has quick-connect technology cut down on labor time, but installers say it is also a neater process because a curing oven and a power source are not needed. James Kraft, president of K. St. James Inc., a cabling installation company in York, PA, maintains that quick-connect connectors have helped his company keep pace with the growing demand for fiber-optic cable--without increasing his staff. He says his 20 technicians have different skill levels. "Quick-connect technology allows the company to use technicians with lesser skills to do the job and do it well," he adds. "We have customers who want work done now--no waiting."
Kraft`s company uses quick-connect products for all horizontal cabling applications. "This technology is well-suited for fiber-to-the-desktop applications," he reports. Ease of installation and the need for only a few tools make it convenient for installers to work under desks and in other tight spaces. "Quick-connects can be installed practically hanging upside down or lying on your back," Kraft says.
Market acceptance for quick-connect fiber-optic connectors, however, has not come easily. In fact, early products did not live up to the reputation for reliability established by connectors installed using traditional epoxy-based methods. The most difficult problem that connector manufacturers have had to overcome has been pistoning--the movement of fiber back and forth within the connector due to changes in temperature or tension on the cable. The pistoning effect can disconnect a connector or degrade performance.
The crimping approach
Instead of using an epoxy bonding process, some vendors produce a crimp-type connector, which mechanically holds the fiber in place by various methods. With its CrimpLok connector, for example, 3M uses a metal element to firmly grip the optical fiber (see Fig. 1). "It`s placed behind the ferrule so you don`t have a lot of glass in the connector to piston," says Dan Silver, 3M market development manager.
According to Silver, the CrimpLok model also provides additional mechanical support at the back end of the connector, or buffer. A plastic buffer-retention insert prevents fiber movement by gripping the buffer without crushing it when the crimp ring is crushed. In addition, the crimp ring grabs the Kevlar strands of the jacketed cable and prevents the fiber connection from breaking when the cable is pulled.
"We`re sensitive to some market opinions that crimp-type connectors don`t hold up like epoxy-type connectors," comments Silver. He believes that installers and end-users need to be educated about the reliability of quick-connect products.
AMP`s LightCrimp connectors are designed to meet long-term performance specifications, as well as eliminate pistoning and fiber protrusion and the subsequent damage they can cause, says AMP`s Peppler. The LightCrimp crimping mechanism clamps on both the buffer and the bare fiber in one motion (see Fig. 2).
To dismiss perceptions that epoxyless connectors aren`t as good as those that use epoxy, the AMP connector crimps to the fiber and the cable at four different points: on the bare glass fiber, the buffer around the fiber, the cable strength members and the cable jacket. The company has found that the best way to convince end-users that epoxyless connector technology works is to let them try it.
Users currently pay a 10% premium for epoxyless connectors compared to traditional products, but savings in labor more than make up for the cost differential. "Between 8 and 28 minutes are saved using epoxyless connectors," says Peppler.
Automatic Tool`s Quick Term and Quick Term-2 products use mechanical methods similar to those of 3M and AMP to achieve a secure, epoxyless, fiber-optic connection. The company also supplies a Terminator connector that needs no epoxy or polishing. Using this connector is easy, according to Al Chaiken, president of Automatic Tool. The installer just strips, crimps and cleaves. Although the Terminator does not require mixing epoxy or curing, the product comes with a preloaded syringe that is used to apply a small amount of adhesive to the fiber near the buffer.
Betty Dean, president of Tricom International Cabling Corp. in Springfield, VA, is an avid supporter of Automated Tool`s Terminator products. "In our business, time is money, and to be competitive, you have to reduce labor time to reduce costs," she says. Dean prefers these connectors because they contain a stainless-steel body for durability. The ferrule is made of zirconia ceramic.
Automatic Tool`s Chaiken notes that the Terminator connector is compatible with all 900- and 250-micron buffer cables. He also says that the Terminator provides low loss without factory or field polishing. The loss specification is 0.35 dB average and 0.6 dB maximum.
Polishing shines
Manufacturers of quick-connect fiber-optic products that require polishing claim that epoxyless connectors reduce polishing time to minutes because there is no epoxy to remove from the glass. Pushing the benefits of field-installable fiber-optic connectors a step further, vendors such as Nordx/CDT and Siecor offer quick-connect products that eliminate the need for polishing. Instead, they polish the fiber and preinstall it in the connector at the factory. "We`ve cut installation time down to a minute," says Richard Plamondon, product manager for fiber products at Nordx/CDT.
To use the company`s Optimax connector, the installer strips and cleaves the fiber, inserts it into the connector, pulls a wire that activates a plunger and then crimps on the 900-micron buffer. The Optimax multimode ST-compatible connector incorporates a prepolished fiber stub and a splice mechanism.
Siecor`s line of singlemode and multimode CamLite (or UniCam) connectors replaces the company`s previous CamLite connector line. Like its predecessor, the UniCam is a no-epoxy, no- polish, field-installable connector. "The UniCam is intended to lower the cost of fiber to the desktop," says Jetta Pyatt, Siecor product manager.
Siecor`s splicing technology employs a universal workstation splicing tool based on a rotating cam action. Installers can therefore use one tool for a variety of connector types, such as ST, SC or FC. Previously, installers had to buy a different tool for each type.
The cost of these Siecor connectors tends to be higher--approximately $9.50 each--than that of other manufacturers` quick-connect products--$4 to $6. However, the universal splicing tool and the reduced labor cost make the UniCam a competitive product, according to the manufacturer. "Our cost argument is technology," states Pyatt. "Other vendors don`t protect the fiber inside the connector; the fiber is bare. We bond and protect the fiber in our connectors with epoxy at the factory."
Mini-pigtail
Best described as a mini-pigtail, the UniCam connector incorporates a fiber stub that is fully bonded into the ferrule. The other end is cleaved and placed into the alignment mechanism of the mechanical splice section of the universal tool. The technician then cleans, cleaves and inserts the field fiber into the mechanical splice. A small installation tool is used to complete the connection in less than one minute.
To help install quick-connect fiber-optic connectors, manufacturers offer special toolkits at varying prices. For example, the Nordx/CDT`s Optimax toolkit costs $539, almost half the cost of most quick-connect toolkits. The Automatic Tool`s Terminator toolkit, however, prices out at $1500.
Other cost factors also come into play in evaluating quick-connect epoxyless products. Depending on the model being evaluated, such as one that requires polish versus one that does not, some costs can be eliminated when compared to those of traditional epoxy connectors. For instance, the cost of consumables drops markedly for quick connects because the requirements for epoxy, curing ovens and polishing paper are eliminated.
Furthermore, quick-connects require less installer training time. Some manufacturers furnish installers with a training video cassette, while others also provide individual or group classroom training. For example, 3M offers a one-week training course every month. u
Lynn Haber is a freelance writer based in Norwell, MA.