Tài liệu The Effect of Moisture docx

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Tài liệu The Effect of Moisture docx

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This white paper will focus on issues related to moisture and its effects on UTP Plenum cabling solutions. For the purpose of argument we will be looking beyond stan- dards and testing for issues that, quite frankly, should never happen under normal circumstances. However, as many of us who have been in the industry for a number of years realize, sometimes the unlikely becomes reality! TrueNet ® AirES ® Technology The Effect of Moisture Ingress on AirES Cable TrueNet ® AirES ® Technology: The Effect of Moisture Ingress on AirES Cable Page 2 The industry bodies have this to say about wet and dry locations: BICSI TDM manual, 9th edition, Chapter 4 – Horizontal Distribution Systems, Section 1 – Horizontal Pathway Systems, final paragraph of page 4-5, which states: Wet Locations Intrabuilding horizontal pathways shall be installed in “dry” locations that protect cables from moisture levels that are beyond the intended operating range of “inside” premises cables. For example, slab-on-grade construction where pathways are installed underground or in concrete slabs that are in direct contact with soil (e.g., sand, gravel, etc.) are considered to be “wet loca- tions.” In the United States, see the NEC, Article 100, for definitions of damp, dry and wet locations. NEC Article 100 – Definitions Locations: Damp locations: Partially protected locations under canopies, marquees, roofed open porches, and like locations, and interior locations subject to moderate degrees of moisture, such as some basements, some barns, and some cold-storage warehouses. Dr y Locations: A location not normally subject to damp- ness or wetness. A location classified as dry may be temporarily subject to dampness or wetness, as in the case of a building under construction. W et Locations: Installations underground or in concrete slabs or masonry in direct contact with the earth or other liquids, such as vehicle washing areas, and loca- tions exposed to weather and unprotected. The above being said, let’s have some fun. The AirES cabling innovation incorporates air pockets around the primary conductor. They run the entire length of the cable (a bit like rifling). These air pockets allow AirES to achieve unparalleled electrical per- formance to overall size. This performance is achieved through mixing the dielectric constant of Air and FEP together to make an overall dielectric constant better than that of FEP alone (for more information please see our “Electrical Attributes” white paper on this subject). It is worth noting the dielectric constant of water is ter- rible when compared with most insulation materials. Additionally, as many people know, mixing amperage with water is never a good idea. For this reason BICSI and the NEC have mandated that UTP cabling be placed in “dry” locations. However we have decided to test how AirES would per- form in a “wet” environment. Because of ADC’s ingen- ious use of air pockets to improve electrical perform- ance, a query has arisen with regards to moisture travel- ing down the air channels themselves. To put this issue to the test, we submerged a sample of AirES cable in a water solution with a dye tracer. For the test we needed a control sample as well and used a competitors cable with solid FEP insulation over the copper conductor. As in the image below, both cables were cut to the same length. The same amount of solu- tion (5ml) was used for each. We then placed both samples (Green AirES and White Competitor) into the solution for a period of 2 hours. It’s worth noting that the fluid level in the AirES graduated cylinder with the cable sample was at 5.95ml. The com- petitor sample fluid level was at 6.1ml. This can be attrib- uted to reduced displacement of fluid with AirES, because of the smaller outer diameter/cross sectional area of the cable. TrueNet ® AirES ® Technology: The Effect of Moisture Ingress on AirES Cable Page 3 After soaking in the solution for 2 hours the cables were removed and the fluid levels were measured to determine how much had soaked into each cable. The competitor sample soaked in 0.15ml of fluid. AirES soaked in 0.05ml of fluid. The reason for the fluid absorption difference was obvi- ous once both samples were cut open. In order to achieve Cat. 6 performance a “star” filler has been used on the competitor cable to separate the pairs (which makes the cable larger). This allows for more “free space” within the cable. Therefore, more fluid to be absorbed. The AirES cable, by introducing air between the copper conductor and the insulation, has less need for pair separation. This allows for the smaller cable size and less absorption. The conductors were then inspected to see how much of the solution was absorbed by the conductors themselves. Above are all 4 pairs of the competitor sample. It would be fair to say that none of the solution absorbed was attributed to the conductors themselves. No penetra- tion was evident. Even though the amount of fluid absorbed by the AirES cable was less, fluid did penetrate the air pockets within the insulation due to capillary action. It flowed up to the level of the fluid within the cylinder. This is most evident in the orange and green pairs, white conductor, with a color change to blue where the dye has penetrated. Although a fascinating result, it is actually quite mean- ingless in a real life installation. This did, however, prove that the air pockets do exist. TrueNet ® AirES ® Technology: The Effect of Moisture Ingress on AirES Cable Page 4 We then tested the cable as it is installed e.g. with a jack attached. A little bit of history about ADC connec- tivity first. One of our claims has been the 45° IDC. With the use of this technology, ADC has been able to achieve a gas tight seal around the contact and in doing so sealed the cabling conductor to that contact. In the example above, ribs (arrow 1) on either side of the connection point squeeze (hold) the insulation to take any disturbance through movement of the cable away from the contact itself. These ribs also help to seal the insulation around the conductor. The IDC, or Insulation Displacement Contact, does just that. It dis- places the FEP insulation around the connection point, which completely seals the junction from gas and/or water ingress. To simulate what might happen if an ADC jack with AirES cable were to be subjected to direct contact with water we submerged a terminated jack into the same water/dye tracer liquid as the first test. In this test we let the cable soak for 14 hours. This was 7 times longer than the first test. The results were astounding. We rinsed the excess dye tracer off of the jack after removal from the liquid (as in the first test conductors). As you can see below, the label to the jack wiring scheme was completely tinted blue from soaking. None of the tracer was evident on any of the pairs. The 45° IDC contacts had com- pletely stopped any penetration whatsoever. TrueNet ® AirES ® Technology: The Effect of Moisture Ingress on AirES Cable Page 5 For the next part of our investigation we subjected AirES cable to a harsh humid environment and meas- ured the effects. To understand the effects, we used an industry standard construction Cat. 6 cable with a star filler as a control. For the purpose of extreme conditions 70°C (158°F) at 95% rH were selected as the temperature and humidity. The cables were placed into the environmental chamber for a period of 5 days. Testing was conducted before the samples were placed in the chamber and one-hour after completion. The results were then compared to show any effect the moist heat may have had on the electrical integrity. TrueNet ® AirES ® Technology: The Effect of Moisture Ingress on AirES Cable Page 6 Although Attenuation, NEXT and Return Loss were effected slightly by the moist environment, the AirES cable tested passed Category 6 requirements. The control sample was then tested in the same man- ner as the AirES sample. TrueNet ® AirES ® Technology: The Effect of Moisture Ingress on AirES Cable Page 7 The results were very surprising. As in our original mois- ture ingress testing, using tracer dye, the control sample seems to have “taken up” more moisture during the humidity testing. Both the Attenuation and NEXT differ- ences looked similar to that of AirES. The Return Loss, however, suffered greatly. We thank our competitor for sparking this investigation. Through it we’ve found yet another advantage to AirES. Moisture ingress appears to be less through hot humid environments, due to the reduced “free air” space inside the cabling jacket. This is evidenced in the Return Loss results before and after humidity testing on “Industry Standard” star filler design Category 6 cable and that of cable integrating AirES technology. Even though these were interesting experiments, it is important the user does NOT use this information as a reason to install cabling in a wet or moist environment! In short, water and networking don’t mix. With that said, it is worth noting the ADC cabling solutions will attract less moisture, due to a reduced cabling size. The connectors will block any moisture ingress on the con- ductors at the cable end. Please remember, we do not recommend running your computer while swimming, bathing or taking a shower. If you must, please use wireless. Web Site: www.adc.com From North America, Call Toll Free: 1-800-366-3891 • Outside of North America: +1-952-938-8080 Fax: +1-952-917-3237 • For a listing of ADC’s global sales office locations, please refer to our web site. WHITE PAPER ADC Telecommunications, Inc., P.O. Box 1101, Minneapolis, Minnesota USA 55440-1101 Specifications published here are current as of the date of publication of this document. Because we are continuous- ly improving our products, ADC reserves the right to change specifications without prior notice. At any time, you may verify product specifications by contacting our headquarters office in Minneapolis. ADC Telecommunications, Inc. views its patent portfolio as an important corporate asset and vigorously enforces its patents. Products or features contained herein may be covered by one or more U.S. or foreign patents. An Equal Opportunity Employer 1317033 5/05 Original © 2005 ADC Telecommunications, Inc. All Rights Reserved KRONE ® is a registered trademark of ADC Telecommunications, Inc. . displacement of fluid with AirES, because of the smaller outer diameter/cross sectional area of the cable. TrueNet ® AirES ® Technology: The Effect of Moisture. of us who have been in the industry for a number of years realize, sometimes the unlikely becomes reality! TrueNet ® AirES ® Technology The Effect of Moisture

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