OBJECTIVES 1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. 13. 14. Understand all components that comprise the entrance facility. Determine the location of the entrance facility. Identify the demarcation point. Understand the different methods used to bring outside plant cable into a building or structure. Understand the difference between grounding and bonding. Identify grounding system components. Understand ground loops Understand retrofitting installation considerations. Determine and understand the need for firestopping. Understand the testing for firestop systems. Identify system solutions for firestop applications and inspecting installations. Identify major codes that require firestopping. Define the term Ground and describe different types of grounds. List the characteristics of a proper telecommunications closet. Figure 3-1: Entrance Facility Figure 3-2: The Demarcation Point The UL Cable Certification Program offers five levels of performance: Level I - cable performance intended for use as basic communications and power-limited circuit cable. There are no performance requirements for cable at this level. Level II - cable performance that is similar to that for Type 3 cable (multipair communications cable) of the IBM Cabling System Technical Interface Specification GA27-3773-1. These requirements apply to cables with between two and 25 twisted-pair conductors that are either shielded or unshielded. The UL Cable Certification Program offers five levels of performance: (continued) Level III - cable performance that complies with the TIA/EIA wiring standards for horizontal unshielded twisted pair cable. These requirements are set forth in the TIA/EIA Technical Bulletin PN-2841. These requirements apply for both shielded and unshielded type cables. The UL Cable Certification Program offers five levels of performance: (continued) Level IV - cable performance that complies with the requirements in the NEMA’s (National Manufacturers Association) standard for low-loss premise telecommunications cable. Level IV requirements are similar to the TIA/EIA standards set forth for Category 4 cabling. These requirements apply for both shielded and unshielded type cables. The UL Cable Certification Program offers five levels of performance: (continued) Level V - cable performance that complies with the requirements in the NEMA’s (National Manufacturers Association) standard for low-loss premise telecommunications cable. Level V requirements are similar to the TIA/EIA standards set forth for Category 5 cabling. These requirements apply for both shielded and unshielded type cable constructions. The location of the entrance facility is determined by several key factors. These are: The location of the local service provider’s lines How the service lines must enter the building The location of the telecommunication closet There are three primary methods by which an outside plant cable may enter a premise: Aerial cable Buried cable Underground cable Figure 3-3: Outside Plant Cable Entry Methods Figure 3-4: Buried Cable Some advantages of buried cable applications are: They preserve the appearance of the premise. They can be easily routed around any obstructions. They offer an inexpensive initial installation cost. The following list contains general requirements for conduit-carrying underground cables to an entrance facility: There should be at least one 4-inch (inside diameter) conduit, plus one spare conduit for future expansion. Most sections may be made of Type C PVC conduit. Entrance conduit should be galvanized steel through the foundation wall to a point 12 inches beyond the disturbed earth. The following list contains general requirements for conduit carrying underground cables to an entrance facility: (continued) Bends in underground conduit should be avoided. If circumstances warrant them, however, a maximum of two 90-degree bends are allowed. The bends should be made of galvanized steel encased in four inches of concrete. Conduit that parallels other utility conduits should maintain a minimum distance of 12 inches. This distance may be reduced to 4 inches if the entrance conduit is encased in four inches of concrete. The following list contains general requirements for conduit carrying underground cables to an entrance facility: (continued) When possible, conduit should be buried at a depth of 48 inches. A shallower depth, but not less than 24 inches, is allowed to avoid obstructions. Conduit entering through a basement or foundation wall should be sloped away so that water cannot run into the building. The advantages of underground conduit entrance facilities are: They preserve the appearance of the premise. The cables are easily maintained or replaced. The conduit provides a protective barrier from external elements such as weather or rodents. Figure 3-5: Typical TC/ER Layout Table 3-1: TC vs. Serving Area Floor Space Table 3-2: ER/EF Wall Length vs. Serving Floor Space Table 3-3: ER/EF Dimensions vs. Serving Floor Space Figure 3-6: Common Ground Potential What should be grounded? 1 All outside-plant copper backbone cables must have their metallic cable shields bonded to the ground lug of the primary protector block at the entrance of each building. 2 Any outside-plant fiber optic cables that contain metallic shielding, or metallic strength members, must have those metallic components bonded to the telecommunications main grounding busbar (TMGB) at each end of the cable. 3 Any inside-plant copper or fiber optic backbone cables that contain metallic shielding must have their shields bonded to the TMGB at each end. What should be grounded? (continued) 4 Where any splices are made to backbone cables, the metallic shields of those cables must be bonded together to maintain shield continuity. There are various methods used to bond metal surfaces. These include soldering, brazing, welding, clamping, sweating, high-strength bolting, or any combination of these. Soldering – an activity that unites metallic surfaces using a soft metal or soft metallic alloy. Brazing - a soldering activity that uses a nonferrous alloy having a lower melting point than the metals being joined. Applying solder to strengthen the ends of copper conductors before bolting them to the grounding frame is a common example of brazing. There are various methods used to bond metal surfaces. These include soldering, brazing, welding, clamping, sweating, high-strength bolting, or any combination of these. (continued) Sweating - the practice of heating metal surfaces to allow solder to melt between their surfaces to unite them. The heat-producing flame or soldering iron does not come into contact with the solder, but rather is used to heat the surface of the joining metals. There are various methods used to bond metal surfaces. These include soldering, brazing, welding, clamping, sweating, high-strength bolting, or any combination of these. (continued) Welding - an activity that unites metals by melting them so that their surfaces flow together to form the bond. Clamping - is a mechanical connection that provides a path between conductors. This type of connection should be avoided and should only be used in temporary equipment where a quick disconnect type of connection is required. There are various methods used to bond metal surfaces. These include soldering, brazing, welding, clamping, sweating, high-strength bolting, or any combination of these. (continued) High strength bolting - an activity where mechanical connections are made with highstrength structural bolts. Figure 3-7: Earth Grounding Figure 3-8: Equipment Grounding WARNING ALL PRECAUTIONS SHOULD BE TAKEN TO PREVENT CONTACT OF THE SKIN WITH THE SOLVENT AND TO AVOID BREATHING THE VAPORS. The components of a typical telecommunications grounding system: Telecommunications main grounding busbar (TMGB) Telecommunications grounding busbar (TGB) Telecommunications bonding backbone (TBB) Telecommunications equipment bonding Conductor (TEBC) Bonding conductor Metal bonding straps Protector panel Grounding electrode Figure 3-9: Typical Telecommunications Grounding System Components TIA/EIA 607 specifies the requirements for: A ground reference for telecommunications systems within the telecommunications entrance facility, the telecommunications closet, and equipment room Bonding and connecting pathways, cable shields, conductors, and hardware at telecommunications closets, equipment rooms, and entrance facilities Figure 3-10: Main Distribution Closet The connection of the TMGB to the building’s main electrical service grounding electrode must be performed by a certified electrical professional. Figure 3-11: Telecommunications Equipment Bonding Conductor However, when installing cable ladder racks or trays, each section must be bonded together. This can be accomplished in one of three ways 1 Remove any paint (down to bare metal) at the point where the rack section interconnection hardware is mounted. Bond the rack assembly to the TMGB with a #6 AWG ground wire. 2 Bond all rack sections together using braided metal bonding straps, or a #6 AWG ground wire. 3 Bond all rack sections to a #6 AWG ground cable run throughout the entire length of the rack or tray. The ground cable must then be bonded to the TMGB. Figure 3-12: Bonding Straps Figure 3-13: Primary Protector Block Figure 3-14: Shielded Twisted Pair Cable Figure 3-15: Ground Loops Figure 3-16: Current Cable Runs The process of tracing current cable runs actually involves several activities: Make sure you check cable records. Check labels on cables. Check the labels on equipment being used. Find out what cables are being used in conjunction with the equipment. Next, make sure that you check the crossconnect archives: Verify all lines at the point of termination. Make a record of which jumpers are connected to which termination points. Use a recommended tone generator (or tone tool) to trace the run to make sure that neither end of the run is connected. Also, confirm the runs on the documents provided: Check the blueprint for accuracy. Confirm backbone labeling, if any, for routing and labeling at termination points. Verify that the equipment rack wiring configurations are correct. Finally, test the current physical connection media: When you are using required testing equipment, substantiate the parameters of the existing horizontal physical connection’s media. Record test results. Test and record copper backbone cables. Use the power meter/light source to test fiber backbone cable and record its readings. Figure 3-17: Testing the Current Physical Connection Media Figure 3-18: Example of Structured Cabling System There are five major steps that you must follow before, during, and after installation: 1 Plan the topology. Determine the planned use of systems. Confirm whether the customer is planning the use of a data system. What will it be? Will it be a combination of systems? Will a new voice system be installed, or will the current system remain? How many wire pairs does the voice system require? Reuse any physical connection media, if possible. There are five major steps that you must follow before, during, and after installation: (continued) 2 Plan the backbone cabling. Determine whether a fiber backbone is required. If so, how many strands are required? Are both multimode and single-mode fiber required? Establish whether there is a need for a copper backbone cable. If so, what paircount and category are required? Figure 3-19: Plan the Backbone Cabling There are five major steps that you must follow before, during, and after installation: (continued) 3 Establish code compliance and standards. Determine the physical borders of the installation. Is CMR-rated or CMP-rated cable to be used? Will firewalls be abtrused? If so, which firestop materials are permitted by local authorities? Verify the need for dismissal of existing cable from conduits and pathways before installation. There are five major steps that you must follow before, during, and after installation: (continued) 3 Establish code compliance and standards. Confirm the status, if any, of asbestos within the facility. If asbestos is present, has it been removed? If not, what planning is required? Verify that the system layout complies with ANSI/TIA/EIA 568A distance limitations for both horizontal and backbone cables. Confirm that the grounding system is designed per ANSI/TIA/EIA 607. Figure 3-20: ANSI/TIA/EIA 568A Distance Limitations There are five major steps that you must follow before, during, and after installation: (continued) 4 Coordinate with other trade groups. a. Electrical contractor Will conduit be provided with pull string for work area outlet locations or will new outlets be required? Determine whether the electric contractor will install the cable tray system, if any, outside of the telecommunications closets (TC). Confirm size, location, and installation of the grounding conductor to the TMGB by the electrical contractor. There are five major steps that you must follow before, during, and after installation: (continued) 4 Coordinate with other trade groups. b. HVAC (Heating, Ventilation, Air Conditioning) Coordinate proposed cable paths with the HVAC contractor to ensure no conflicts exist with ductwork, access panels, fan coil units, etc. Review mechanical, electrical, and plumbing plans, if provided, so as to plan routing of horizontal cables. c. Ceiling/Drywall/Painting contractors Confirm timeframe for ceiling grid installation and dropin tile placement to ensure agreement with timeframe planned for cable placement. Coordinate workstation termination with drywall and painting contractor to ensure no conflict exists. There are five major steps that you must follow before, during, and after installation: (continued) 4 Coordinate with other trade groups. d. Furniture contractor Determine the planned timeframe for any modular furniture installation. Verify furniture installation procedures. Will cabling be installed through utility poles or fed from floor mount boxes? Establish what the connecting hardware should be, based on the make and model of the modular furniture. Does the system provide adequate space to maintain bend radius requirements, or will surface boxes be required? Find out who is responsible for the final installation of furniture base plates. There are five major steps that you must follow before, during, and after installation: (continued) 5 Plan the cutover. a. Establish the method of implementation. Confirm whether work will be done after or during normal business hours. Verify who is responsible for the interconnection of voice and data systems to the new physical connection media. Will the system be cutover under a flash cut scenario, or will it be phased in over a period of time in preplanned stages? Does the customer need on-site support both during and after the cutover? Based on the size and scope of the project, will there be any scheduled construction meetings for trade coordination? There are five major steps that you must follow before, during, and after installation: (continued) 5 Plan the cutover. b. Testing Perform all appropriate copper testing for all new cables using either link or channel tests, as determined by the customer, to meet TIA/EIA TSB 67 specifications. Perform fiber testing, using either a power meter/light source or an OTDR, as specified by the customer. Figure 3-21: Copper Testing There are five major steps that you must follow before, during, and after installation: (continued) 5 Plan the cutover. c. Documentation Label all cabling as authorized according to ANSI/TIA/EIA 606. Enhance blueprints for the “as-built” document. Supply interconnection drawings. Make sure you supply rack layout drawings. Produce all test results in both hard copy and electronic media. There are five major steps that you must follow before, during, and after installation: (continued) 5 Plan the cutover. e. Remove the cable support hardware. Distract all tie wraps from cables to be removed. Disconnect all fasteners from cable bundles to be taken out. Make sure you remove all cable terminations. Disconnect all cables from work area outlets being taken out. Remove all terminations in the telco closet. f. Remove the cabling. Carefully salvage cables for disposal. Properly eliminate cable. Figure 3-22: Fire-Rated Barriers Figure 3-23: Caulk and Putty Application The following list provides some practical points to consider when you are performing a cable installation that requires firestopping: Contact the local building inspector and fire marshal to make certain you are familiar with the current code regulations. Check your company’s standard policies for procedures related to installing firestopping materials. If no policy or procedures exist, one should be created. The following list provides some practical points to consider when you are performing a cable installation that requires firestopping: (continued) Review the instructions supplied by the intumescent material’s manufacturer. Check to make sure all of the materials involved in the installation are approved by a legitimate, recognized testing organization (such as Underwriters Laboratories, Inc.). The following list provides some practical points to consider when you are performing a cable installation that requires firestopping: (continued) Use the following recommendations when performing the actual installation: Drill oversized holes for the installation so that the cable or conduit fits easily through the penetration. However, do not make the opening so large that it impacts the manufacturer’s minimum depth thickness specification for the caulk or putty. Never substitute nonfire-rated packing (such as regular insulation) for fire-rated materials (such as wool bat). Never reuse an existing firestop that does not meet code. This may make you liable for the complete installation. The following list provides some practical points to consider when you are performing a cable installation that requires firestopping: (continued) Use the following recommendations when performing the actual installation: Protect yourself by documenting your installation. This can be done with an inexpensive camera. Simply record the important information about the installation on the wall beside the penetration. Then, take a photograph of it for your files. If anyone violates the fire code at a later date, or an actual fire occurs, you have the photograph as evidence of your work. Some of the major codes requiring firestopping arrangements are: National Building Code - Building Officials and Code Administrators (BOCA), which provides a standard of construction regulations and supports the enforcement of these regulations. Standard Building Code - Southern Building Code Congress International (SBCCI), which provides the same standards of construction regulations as the BOCA but is used mainly in the southern part of the United States. Some of the major codes requiring firestopping arrangements are: (continued) Uniform Building Code - International Conference of Building Officials (ICBO) is a building code used mainly in the western part of the United States. International Building Code - International Code Council (ICC) is made up of representatives from the BOCA, ICBO, and SBCCI. This council’s purpose is to combine the codes of the three model building code organizations to make a single national model building code for use mostly in the United States. Some of the major codes requiring firestopping arrangements are: (continued) Fire Prevention Code (NFPA 1) - Provides basic fire prevention requirements necessary to establish a reasonable level of fire safety and property protection from the hazards produced by fire and explosion. National Fuel Gas Code (NFPA 54) - Provides the safety requirements for fuel gas equipment installations, piping, and venting. National Fire Alarm Code (NFPA 72) - Sets minimum standards for fire alarm systems. Some of the major codes requiring firestopping arrangements are: (continued) Life Safety Code (NFPA 101) - Provides for minimum building design, construction, operation, and maintenance required to protect building occupants from the dangers of the effects of fire. National Electric Code (NFPA 70) - Provides for proper installation of electrical systems and equipment. Some of the major codes requiring firestopping arrangements are: (continued) Occupational Safety and Health Standards (29 CFR Part 1910) - Occupational Safety and Health Administration (OSHA) requires all facilities to take steps to provide for minimum worker protection. Some situations that could potentially affect the performance of the installed firestop include: The type and size of the penetrating items (type of pipe or wire through the wall or floor) The percentage of cable fill and the annular space (the amount of cable and the size of the space it’s going through) The type and thickness of the insulation The type and thickness of the wall or floor The severity of the fire itself (how bad the fire is and how hot) The quality of the installation (how well the firestop was installed) You should always install firestopping in the following locations: Openings between floor slabs and curtain walls, including hollow curtain walls at the floor slabs Openings and penetrations in enclosures with time-rated fire doors Openings between walls and ceilings of timerated assemblies Figure 3-24: Firestopping Retardant Application Figure 3-25: Fire Path The following list names some of these materials and describes their characteristics: Cementitious materials are firestopping materials having properties that are similar to cement. Cementitious materials come in two basic forms: Dry powder - water mix Premixed Intumescent sheet is used to form a honeycomb partition opening. Special provisions include: Layering (one thickness, course, or fold laid over or under another) Spacing (providing with spaces of placing at intervals) Anchoring (a reliable or main support) Sealing (the ability of a component to resist the entrance of contaminants) Figure 3-26: Cementitious Mortar Application The following list names some of these materials and describes their characteristics: (continued) Caulk can vary in its ability to: Adhere (its ability to hold fast or stick) Flexibility (the capability to adapt to a new, different, or changing environment) Some type of caulk remain permanently soft while some cure to a solid. Moisture resistance (how well it resists moisture) The following list mentions several of these components and collects them into related groups. 1 Telecom and electrical Conduit - plastic and metal Cable - power, control, telephone, fiber optic, metalclad, coaxial Bus duct (self-supporting bridge construction) Cable tray (a suspended tray that contains various telephone or computer cables) The following list mentions several of these components and collects them into related groups. (continued) 2 HVAC (air conditioning) Round openings Rectangular openings Insulated openings Noninsulated openings Multiple openings The following list mentions several of these components and collects them into related groups. (continued) 3 Mechanical Piping, insulated and noninsulated: Plastic: CPVC, PVC, CCPVC, ABS, CCABS, PB, PP, PVDF, and double containment Metal: Steel, cast iron, copper, and aluminum Uses include: Chiller lines Sprinkler systems Water supply lines Steam lines Acid drains Process pipes DWV Figure 3-27: Firestop Pillows A few precautions you should take in order to properly install and maintain firestop pillows: Inspecting all areas to be protected Removing any sharp edges, protruding wires, or ties that could damage the poly bags Arranging cables to present a smooth and even surface Calculating pillow requirements in square inches in advance as an indicator of the proper installed volume and compression Keeping them away from wire mesh that may be required as a part of the installation process or given as an option to facilitate installation Figure 3-28: Firestop Collar Figure 3-29: Wrap Strip Wrap strip installation procedures: 1 (Tuck-in installations) Wrap a layer of wrap strip around the penetrant. You may use masking tape to temporarily secure the strip. Apply successive layers of wrap strip as required by the system chosen. 2 Secure the wrap strip in place with steel tie wire or foil tape. 3 It is recommended that both sides of the wall, and the top and bottom of the floors, be caulked. Wrap strip installation procedures: (continued) 4 (Restraining collar installations) Calculate the required length of the restraining collar needed to completely wrap around the outer diameter of the wrap strip rings. Include an additional inch for overlap. Requirements for Firestop Testing: Exposure to severe fire under positive pressure Room temperature must reach 1,000ºF within 5 minutes Room temperature must reach 1,700º in 1 hour Room temperature must reach 1,850º in 2 hours Room temperature must reach 1,925º in 3 hours Room temperature must reach 2,000º in 4 hours Requirements for a Hose Stream Test: A Powerful water hose stream A 2 1/2-inch hose with a 1 1/8-inch hose nozzle. A 1 to 3 hour test with water applied at 30 psi for a specified length of time, based on an hourly rating and the size of the test surface. A 4-hour test with water applied at 45 psi for an extended period of time, based on the size of the test surface. Fire rating categories include: Fire: The rating that provides the time period for which the system is capable of blocking passage of flame through the system (and requires acceptable hose stream performance) is called the Flame or (F) rating. Temperature: The Temperature or (T) rating provides the time period for which the system is capable of limiting maximum temperature rise in the unexposed surface of the wall, floor assembly or the penetrating item, and on the fill material in the open space—not to exceed 325ºF (181ºC) above the initial temperature. It also requires acceptable stream performance. Fire rating categories include: (continued) Leakage: The Leakage or (L) rating provides information concerning the amount of air leakage, specified in cubic feet per square foot of an opening, through the firestop system and/or 40ºF air temperature. FH Rating: The firestopping system meets the requirement of an FH rating if it remains in the opening during both the fire test and the hose stream test, within the limitations of an (F) rating. Also, during the hose stream test, the system should not develop any openings that would permit a projection of the stream past the unexposed side. Fire rating categories include: (continued) FTH Rating: The firestopping system meets the requirements established for an FTH rating if it remains in the opening during the fire test and the hose stream test, within the limits set for the (F), (T), and (FH) ratings. REVIEW QUESTIONS 1 You are installing an underground conduit for entrance cable. The architect has left a very old tree on the property that lies directly between the local service provider’s service manhole and the entrance closet. Can you run the conduit around the tree? REVIEW QUESTIONS 2 What is the expected electrical voltage level of an equipment ground? REVIEW QUESTIONS 3 _________ and _____________ are some of the main causes of electronic equipment failure. REVIEW QUESTIONS 4 Describe a good first-step practice to employ when troubleshooting an intermittent network communication problem. REVIEW QUESTIONS 5 In a telecommunications installation, where would you find a TMGB? REVIEW QUESTIONS 6 How is the TMGB bonded to the building’s main electrical service grounding electrode? REVIEW QUESTIONS 7 When all TGBs in a building are bonded together along with the TMGB, what structure is created? REVIEW QUESTIONS 8 What is the purpose of the protector unit in a primary protector block? REVIEW QUESTIONS 9 What is a retrofit installation as it applies to entrance facilities? REVIEW QUESTIONS 10 What is the most overriding reason for implementing firestopping?