Comparing connector technologies: which to use where
Understanding connection options is essential to maintaining control of labor costs on fiber-optic installations.
BY HERB CONGDON
There's no doubt that the choices available today in connector technology make it easier than ever for installers to field-mount fiber-optic connectors. But with several technologies to choose from-heat-cured epoxy, quick-cure (anaerobic) adhesive, no-epoxy, polish, and no-polish-selecting the right one for your application can make a difference in how quickly and cost-effectively the job gets done. In addition to following the guidelines presented here for making the right choice, other considerations can include labor rate, work force training, the size of your optical fiber business, connector performance, and type of project.
Keep in mind that connector technologies, not connector type, determine how the connection occurs. Therefore, as a basis for comparison, consider these factors when choosing connection technologies.
- Setup time. Refers to the preparation time required before installing the first connector at a termination location and includes getting the necessary tools out, setting up a polishing area, mixing epoxy, and filling up an applicator, if required.
- Installation time. The time it takes to install a connector on a 900-micron buffered fiber on stripped cable, including stripping the buffer, mixing epoxy, loading syringes, curing the epoxy, polishing, and crimping, as required.
- Costs. Includes the comparative costs of the various connector types along with the costs of consumables (adhesives, polishing papers), and any necessary tools.
- Skill level. While some level of training is required for all connectors, technologies are now available that allow installers with limited training to produce good results.
- Advantages. Represents the lowest cost for connectors. Fast-curing adhesives are available.
- Application. Best suited for locations with large fiber-count cables, where many fibers can be terminated at a single work location. Typically used in backbone cables, either campus or within a building as well as at the telecommunications closet when terminating many fiber-to-the-desk cables. A good method for installers with low labor costs and a stable, trained work force.
Heat-cured epoxy was the first connector technology introduced and is still widely used today. This technique, which requires an oven and a 20-minute curing cycle, is best suited for terminating high-fiber-count cables (more than 24 fibers). In these situations, setup time is not as significant because you can establish an assembly-line type of process to gain efficiencies. While some connectors are being polished, others are in the curing oven. Today, faster curing adhesives are available that considerably reduce the curing time, often to within two minutes, without the need for an oven and power source. Anerobic polish technology also is available and helps decrease installation time.
- Setup time. Takes approximately 10 minutes, because the adhesive and polish station must be prepared before starting.
- Installation time. Takes an average of three to five minutes for a large number of connectors; as long as 25 minutes for a single connector.
- Cost. This method has the lowest component cost per connector, but does require a separate investment in a curing oven and polishing station. Additional consumables costs for the adhesives and polishing papers must also be considered. For these reasons, the epoxy-polish connectors are viable only if these costs can be spread across a large number of connectors.
- Skill level. This technique is not difficult, but it requires the most training and skill, specifically in the application of the adhesive and the polishing of the connector. These skills are easy to learn and master; however, they must be taught and acquired to produce consistently good results. Accordingly, this technique is most suited to installation companies with a trained work force, low turnover rates, and low labor costs. Due to the time required, high labor rates can adversely affect the cost-effectiveness of this technology.
- Advantages. Moderate material cost, reduced setup time, reduced training, and reduced consumable costs.
- Application. No-epoxy is ideal for locations with moderate-fiber-counts cables (12-24 fibers) or for companies that perform a mixture of backbone and fiber-to-the-desk projects. It is easily adaptable for high-fiber-count and low-fiber-count locations. Ideal for installers with moderate labor costs and a reasonably stable, trained work force.
No-epoxy polish connectors replace the need for epoxy by using a crimp or clamp mechanism to keep the fibers in place within the ferrule. The excess fiber is then cleaved and polished to produce a working connector. No-epoxy is a popular choice for installers because it eliminate two of the industry's primary complaints: the need to mix and apply epoxy and/or adhesives and the need for ovens, power, or even UV-curing lights. Thus, there is a reduced capital investment and a lower consumables cost.
- Setup time. Takes about five minutes.
- Installation time. Takes an average of less than two minutes for several connectors.
- Cost. Moderate-the cost of connector components is somewhat higher, but there is no need for an oven or epoxy/adhesive. Special tools are usually required; however, the tools are typically simple and inexpensive and can be used for many years.
- Skill level. The amount of training and skill is reduced because the crimp mechanism is easier to master than mixing and applying epoxy. For maximum flexibility with one technology, many installers consider these connector types the best choice because of the balance between skill and cost.
- Advantages. No setup time required. Lowest installation time per connector. Limited training required. No consumables costs.
- Application. No-epoxy/no-polish connectors are ideal for locations with low-fiber-count cables (less than 12 fibers), including small building backbones or fiber-to-the-desk applications with installation sites spread over a large area. Ideal for installers with high labor rates and/or high turnover rate of technicians. Simplifies maintenance, repairing, and troubleshooting as well as moves, adds, and changes when cables are being added or relocated.
No-epoxy/no-polish connectors offer the easiest and quickest termination technology available. Installers only need to strip, cleave, and insert the fiber into the connector. Many installation companies choose these connectors for small optical-fiber projects, typically 12-fiber or less, where reducing setup time and eliminating the need for a curing oven help realize significant savings. Additionally, only a small amount of excess fiber length is required, reducing the amount of fiber stored at the outlet. End users that perform these operations (without hiring an installer) will often find these connectors to be the best solution.
Finally, there is also a technical benefit, since the endface polish quality and resulting return-loss performance of the connector is determined by the manufacturer, not by the installers.
- Setup time. Essentially none.
- Installation time. Less than one minute per connector, regardless of number.
- Cost. Highest cost per connector components, since some of the labor (polishing) is done in the factory. However, it may still be less expensive on a cost-per-installed-connector basis because there is a lower labor cost. Some connectors require special tools, but again, the tools are usually simple and inexpensive.
- Skill level. Installers require a minimum amount of training, making this type of connector ideal for installation companies with a high turnover rate of installers and/or that do limited amounts of optical-fiber terminations.
The connector technology or technologies you select will be determined by the requirements of your installations and personal preferences. Many enterprises utilize multiple technologies, depending on the application, for example, using epoxy-polish or hot-melt adhesive connectors at the closet location and no-epoxy, no-polish connectors at the outlets for fiber-to-the-desk projects. You may elect to give the testing crew no-epoxy, no-polish connectors for replacing any connectors found to be outside of the specifications at the time of testing to quickly complete the verification process.
Familiarity with the time requirements, costs, and skill-level requirements for each connector technology will enable an installer to select the optimum technology for any installation. Most important is that whatever connector technology you choose, always use optical connectors that meet or exceed the requirements established by ANSI/TIA/EIA-568B.3, ISO-11801, and EN-50173.
Herb Congdon, market manager, fiber, for AMP Netconnect Systems (Harrisburg, PA), wrote this article on behalf of the TIA Fiber Optics LAN Section (FOLS). Member companies include 3M/Volition, Allied Telesyn International, AMP Netconnect, Belden Wire & Cable, Berk-Tek, CommScope, Corning, LANcast, Leviton Voice and Data Div., Lucent Technologies, Micro Linear, Ortronics, Panduit, the Siemon Co., Siecor, Sumitomo Electric Lightwave, and Transition Networks. Visit the FOLS Website at www.fols.org.