摘要 :
Changing environmental interests and new fire safety performance concerns in the wire and cable industry (WCI) have generated studies into the fire hazard and eco-performance of various data and communication cabling system altern...
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Changing environmental interests and new fire safety performance concerns in the wire and cable industry (WCI) have generated studies into the fire hazard and eco-performance of various data and communication cabling system alternatives for computers and local area networks (LAN). To accurately assess the various alternatives, the installed electronic functionality and fire safety performance requirements of the various end-use product options must be equivalent. For high fire performance communication cables (HFP-cables), many existing local and national regulations differentiate between end product performance options and building fire protection needs. High fire-performance, high societal-value based PVC sheathed and perfluoropolymer (PFP) insulated (PVC/PFP) cables can be routed directly in concealed plenum spaces in buildings, while products that do not meet specific high fire performance criteria, such as low-smoke zero-halogen (LSZH/PE) cables or riser-rated cables (CMR or PVC/PE), often must be protected inside other structures that do meet these building fire standards, typically using steel conduit or trunking. However, some low fire performance LAN cables, even fire-protected inside steel conduits, failed to meet the minimum flame spread and smoke criteria that HFP-cables must meet in real-scale cable, fire tests at BRE/FRS and Underwriters Laboratories (when tested as a cable in steel conduit system). Life cycle analysis (LCA) via ISO 14040 methodology is used to evaluate the various cabling alternatives using an appropriate functional unit; a CAT 6 communication LAN cabling system in a typical office building, including cable, steel conduit, couplings and supports as required per building codes for the installation. Key environmental impact assessments for energy consumption, greenhouse gas emissions, and human toxicity are all shown to favor the PVC/PFP systems once the steel conduit is included in the analysis to fire-protect the LSZH/PE or PVC/PE cables. The additional fire safety and installation advantages provided by the PVC/PFP cables more than offsets for the environmental burdens associated with the initial manufacture of just the cable, thereby providing superior overall fire safety, environmental performance, and economic benefits versus LSZH/PE and PVC/PE cables in steel conduits.
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This paper presents preliminary comparative environmental life-cycle assessment results for resin systems with alternative heat stabilizer formulations for Category 6, riser-rated communication cable (CMR) and Category 6, plenum-r...
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This paper presents preliminary comparative environmental life-cycle assessment results for resin systems with alternative heat stabilizer formulations for Category 6, riser-rated communication cable (CMR) and Category 6, plenum-rated communication cable (CMP) cables. Based on primary and secondary data, this paper presents impact results for 14 categories: energy, non-renewable resources, public non-cancer toxicity, public cancer toxicity, occupational non-cancer toxicity, occupational cancer toxicity, aquatic ecotoxicity, global warming, stratospheric ozone depletion, air acidification, photochemical smog, water eutrophication, landfill space use, and air particulate matter. Monte Carlo-based uncertainty analyses for the major sources of uncertainty in the life-cycle models are also presented.Preliminary CMR results showed that leaded cable is likely to have greater environmental burdens over the lead-free alternatives for the public chronic non-cancer toxicity and the aquatic ecotoxicity categories; and decreased environmental burdens for the occupational non-cancer toxicity and landfill space categories. Given the uncertainty, primarily from cable manufacturing energy, CMR results were inconclusive for the remaining 10 categories. Preliminary CMP results revealed that public chronic non-cancer toxicity, aquatic ecotoxicity, and stratospheric ozone depletion are expected to have greater environmental burdens for the lead as compared to the lead-free alternative; and the remaining 12 impact categories were inconclusive due almost exclusively to uncertainty in the manufacturing energy estimates.
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The Ethernet protocol is not only applied in administrative environment anymore, but also has being used in factory, connecting equipments to the company network management. The Ethernet protocol application is also extended to no...
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The Ethernet protocol is not only applied in administrative environment anymore, but also has being used in factory, connecting equipments to the company network management. The Ethernet protocol application is also extended to non-industrial companies, where cabling is strongly exposed to some kind of aggression or attack from non-conventional elements. In the majority of installations, a standard Ethernet cable is used and its protection is done in a precarious and non-appropriated way. Considering extremely aggressive environments, with water, acids, oils and dust in the air, in a short period of time, cabling starts to deteriorate and to cause transmission failures.In this paper, we are intending to present the Ethernet cable developed to complement a structured cabling system for hazardous environments, with appropriated protection indexes to support the attack of several elements. This cable will present a better performance and less maintenance.
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Microscale combustion calorimetry (MCC) has recently become commercially available for assessing flammability of polymers using only milligrams of test specimen. Although significant data and correlations with conventional flammab...
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Microscale combustion calorimetry (MCC) has recently become commercially available for assessing flammability of polymers using only milligrams of test specimen. Although significant data and correlations with conventional flammability tests such as UL 94, Limiting Oxygen Index, and cone calorimetry are available in the literature, correlation data for polymers containing flame retardants are still limited. In this study, we conducted MCC on 15 commercially available flame retardant wire and cable compounds. The MCC parameters measured include heat release capacity, temperature at peak specific heat release rate, total heat release, and char yield. These parameters were correlated with the conventional flammability tests and the results are discussed in this paper.
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Life-Cycle Analysis (LCA) can be used to evaluate the environmental effects of a product, process, or activity. An LCA is a comprehensive method for evaluating the full life cycle of the product system from materials acquisition t...
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Life-Cycle Analysis (LCA) can be used to evaluate the environmental effects of a product, process, or activity. An LCA is a comprehensive method for evaluating the full life cycle of the product system from materials acquisition to manufacturing, use, and final disposition. The Society of the Plastics Industry, Inc. (SPI) is expanding upon a current LCA study to evaluate functionally equivalent alternative solutions for data communication cables in plenum spaces. Essentially, the project will generate information on the environmental impacts of functionally equivalent cable installations of perfluoropolymer-insulated (PFP) cable versus a polyethylene-insulated (PE) cable in metal conduit; enabling building owners, architects, and HVAC engineers to make environmentally sound product and material choices. There are four major components of an LCA study as described in the International Organization for Standardization (ISO) 14040: goal definition and scoping, life-cycle inventory (LCI), impact assessment, and interpretation of results. This paper presents the goal, definition, and scope of the LCA, including the purpose and background of the project, descriptions of the product systems being evaluated, and the boundaries used in this study.
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This paper presents measured results for the twisted pair common mode circuit impedance and attenuation unbalance of 4 pair Category 6 UTP and FTP cable. The attenuation unbalance was measured with terminating impedances described...
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This paper presents measured results for the twisted pair common mode circuit impedance and attenuation unbalance of 4 pair Category 6 UTP and FTP cable. The attenuation unbalance was measured with terminating impedances described by TIA 568-B.2 and by matching the average measured values. The cables were mounted on either a dielectric drum or a grooved metallic surface drum. The return path was formed by short or open circuit connection of pairs not under test to the metallic drum. The UTP cable common mode impedance was found to vary about ±9% depending on the test environment. The effect of terminating impedance and grounding status of the drum on the unbalance parameters (TCL, TCTL, LCL, LCTL) was found to be negligible.
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Poorly grounded feed-through configurations can be a prominent source of electromagnetic compatibility (EMC) and interference (EMI) problems. Based on the by IEC and CENELEC standardized shielding effectiveness test methods of cab...
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Poorly grounded feed-through configurations can be a prominent source of electromagnetic compatibility (EMC) and interference (EMI) problems. Based on the by IEC and CENELEC standardized shielding effectiveness test methods of cables, connectors and cable assemblies in IEC 62153-4 series, a new simple test method to measure in well defined circumstances the transfer impedance and shielding or screening attenuations of feed-through configurations and electromagnetic interference (EMI) gaskets has been developed and tested with good results.. Using the S parameters measured with a network analyzer (NWA), the transfer impedance is calculated. It is the primary and test fixture independent screening effectiveness quantity and allows an estimation of the screening efficiency also within systems with changed impedances. This method can on one hand be used to specify screening effectiveness of EMI gaskets on component level; on the other hand it emphasizes the feed-through to be one prominent source of EMI radiation.The designed and constructed test fixture has a capability with a proper NWA to measure the transfer impedance to and below 15 micro ohm, corresponding to a normalized screening attenuation (for feed-throughs or gaskets) of 130 dB.
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Historically, lead-based stabilizers have been formulated in flexible PVC compounds for wires and cables. However, concerns over the toxicity and environmental impact of these stabilizers have forced the industry to search for alt...
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Historically, lead-based stabilizers have been formulated in flexible PVC compounds for wires and cables. However, concerns over the toxicity and environmental impact of these stabilizers have forced the industry to search for alternatives. The UL 83 Long-Term Insulation Resistance performance of wire insulated with a non-lead stabilized PVC compound tested in water for 26 weeks at THWN and THWN-2 test conditions are presented. In addition, the volume resistivity and dielectric properties are compared between lead and non-lead stabilized versions of the compound. NFPA 262 Steiner Tunnel burn test results are also presented from three communication cables, each jacketed with a different non-lead, non-ammonium octamolybdate PVC plenum compound. The effect of non-lead vs. lead stabilizers on dielectric, rheological, thermal stability, and Limiting Oxygen Index properties is also compared in the same plenum compounds. Finally, a compound possessing excellent performance attributes for plenum cable applications is presented.
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Reduction of bending loss has been recognized as an important aspect in optimizing single mode fibers for FTTH applications. This paper highlights some characteristics of different implementation types of bend-insensitive fiber. I...
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Reduction of bending loss has been recognized as an important aspect in optimizing single mode fibers for FTTH applications. This paper highlights some characteristics of different implementation types of bend-insensitive fiber. In addition the advantages of such fiber in connectivity and new indoor cable designs are presented.
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Based on eye diagram measurements, a new and intuitive simulation of Bit Error Rate (BER) results for multimode fiber links, including noise floors, is described here. Both the zero- and one-logic levels are comprised of four comp...
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Based on eye diagram measurements, a new and intuitive simulation of Bit Error Rate (BER) results for multimode fiber links, including noise floors, is described here. Both the zero- and one-logic levels are comprised of four component Gaussian distributions, which accurately describe the whole distribution and accurately describe the associated BER. Analysis of the standard deviations of the Gaussian distributions leads to the conclusion that BER noise floors are caused only at the one-logic level.
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