VA 27 05 26-2006 GROUNDING AND BONDING FOR COMMUNICATIONS SYSTEMS.pdf

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1、10-06M 27 05 26 - 1 SECTION 27 05 26 GROUNDING AND BONDING FOR COMMUNICATIONS SYSTEMS SPEC WRITER NOTE: Delete / _ / if not applicable to project. Also delete any other item or paragraph not applicable in the section and renumber the paragraphs. Insert additional provisions as required for this proj

2、ect. PART 1 - GENERAL 1.1 DESCRIPTION A. This section specifies general grounding and bonding requirements of telecommunication installations for equipment operations. B. “Grounding electrode system” refers to all electrodes required by NEC, as well as including made, supplementary, telecommunicatio

3、ns system grounding electrodes. C. The terms “connect” and “bond” are used interchangeably in this specification and have the same meaning. 1.2 RELATED WORK A. Section 27 05 11, REQUIREMENTS FOR COMMUNICATIONS INSTALLATIONS: General electrical requirements and items that are common to more than one

4、section of Division 27. B. Section 27 10 00, STRUCTURED CABLING: Low Voltage power and lighting wiring. C. Section 26 41 00, FACILITY LIGHTNING PROTECTION: Requirements for a lightning protection system. 1.3 SUBMITTALS A. Submit in accordance with Section 27 05 11, REQUIREMENTS FOR COMMUNICATIONS IN

5、STALLATIONS. B. Shop Drawings: 1. Sufficient information, clearly presented, shall be included to determine compliance with drawings and specifications. 2. Include the location of system grounding electrode connections and the routing of aboveground and underground grounding electrode conductors. C.

6、 Test Reports: Provide certified test reports of ground resistance. D. Certifications: Two weeks prior to final inspection, submit four copies of the following to the Resident Engineer: 1. Certification that the materials and installation is in accordance with the drawings and specifications. Provid

7、ed by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-10-06M 27 05 26 - 2 2. Certification, by the Contractor, that the complete installation has been properly installed and tested. 1.4 APPLICABLE PUBLICATIONS Publications listed below (including amendments, add

8、enda, revisions, supplements, and errata) form a part of this specification to the extent referenced. Publications are referenced in the text by the basic designation only. A. American Society for Testing and Materials (ASTM): B1-2001 Standard Specification for Hard-Drawn Copper Wire B8-2004 Standar

9、d Specification for Concentric-Lay-Stranded Copper Conductors, Hard, Medium-Hard, or Soft B. Institute of Electrical and Electronics Engineers, Inc. (IEEE): 81-1983 IEEE Guide for Measuring Earth Resistivity, Ground Impedance, and Earth Surface Potentials of a Ground System C. National Fire Protecti

10、on Association (NFPA): 70-2005 National Electrical Code (NEC) D. Telecommunications Industry Association, (TIA) J-STO-607-A-2002. Commercial Building Grounding (Earthing) and Bonding Requirements for Telecommunications E. Underwriters Laboratories, Inc. (UL): 44-2005 . Thermoset-Insulated Wires and

11、Cables 83-2003 . Thermoplastic-Insulated Wires and Cables 467-2004 Grounding and Bonding Equipment 486A-486B-2003 Wire Connectors PART 2 - PRODUCTS 2.1 GROUNDING AND BONDING CONDUCTORS A. Equipment grounding conductors shall be UL 83 insulated stranded copper, except that sizes 6 mm (10 AWG) and sma

12、ller shall be solid copper. Insulation color shall be continuous green for all equipment grounding conductors, except that wire sizes 25 mm (4 AWG) and larger shall be permitted to be identified per NEC. B. Bonding conductors shall be ASTM B8 bare stranded copper, except that sizes 6 mm (10 AWG) and

13、 smaller shall be ASTM B1 solid bare copper wire. Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-10-06M 27 05 26 - 3 C. Isolated Power System: Type XHHW-2 insulation with a dielectric constant of 3.5 or less. D. Telecom System Grounding Riser Conduc

14、tor: Telecommunications Grounding Riser shall be in accordance with J STO-607A. Use a minimum 50mm (1/0 AWG) insulated stranded copper grounding conductor unless indicated otherwise. 2.2 GROUND RODS A. Copper clad steel, 19 mm (3/4-inch) diameter by 3000 mm (10 feet) long, conforming to UL 467. B. Q

15、uantity of rods shall be as required to obtain the specified ground resistance. 2.3 SPLICES AND TERMINATION COMPONENTS Components shall meet or exceed UL 467 and be clearly marked with the manufacturer, catalog number, and permitted conductor size(s). 2.4 TELECOMMUNICATION SYSTEM GROUND BUSBARS A. P

16、rovide solid copper busbar, pre-drilled from two-hole lug connections with a minimum thickness of 6 mm (1/4 inch) for wall and backboard mounting using standard insulators sized as follows: 1. Room Signal Grounding: 300 mm x 100 mm (12 inches x 4 inch). 2. Master Signal Ground: 600 mm x 100 mm (24 i

17、nches x 4 inch). 2.5 GROUND CONNECTIONS A. Below Grade: Exothermic-welded type connectors. B. Above Grade: 1. Bonding Jumpers: compression type connectors, using zinc-plated fasteners and external tooth lockwashers. 2. Ground Busbars: Two-hole compression type lugs using tin-plated copper or copper

18、alloy bolts and nuts. 3. Rack and Cabinet Ground Bars: one-hole compression-type lugs using zinc-plated or copper alloy fasteners. A. Cable Shields: Make ground connections to multipair communications cables with metallic shields using shield bonding connectors with screw stud connection. 2.6 EQUIPM

19、ENT RACK AND CABINET GROUND BARS Provide solid copper ground bars designed for mounting on the framework of open or cabinet-enclosed equipment racks with minimum dimensions of 4 mm thick by 19 mm wide (3/8 inch x inch). Provided by IHSNot for ResaleNo reproduction or networking permitted without lic

20、ense from IHS-,-,-10-06M 27 05 26 - 4 2.7 GROUND TERMINAL BLOCKS At any equipment mounting location (e.g. backboards and hinged cover enclosures) where rack-type ground bars cannot be mounted, provide screw lug-type terminal blocks. 2.8 SPLICE CASE GROUND ACCESSORIES Splice case grounding and bondin

21、g accessories shall be supplied by the splice case manufacturer when available. Otherwise, use 16 mm (6 AWG) insulated ground wire with shield bonding connectors. PART 3 - EXECUTION 3.1 GENERAL A. Ground in accordance with the NEC, as shown on drawings, and as hereinafter specified. B. System Ground

22、ing: 1. Secondary service neutrals: Ground at the supply side of the secondary disconnecting means and at the related transformers. 2. Separately derived systems (transformers downstream from the service entrance): Ground the secondary neutral. 3. Isolation transformers and isolated power systems sh

23、all not be system grounded. C. Equipment Grounding: Metallic structures (including ductwork and building steel), enclosures, raceways, junction boxes, outlet boxes, cabinets, machine frames, and other conductive items in close proximity with electrical circuits shall be bonded and grounded. SPEC WRI

24、TER NOTE: If appropriate for project, include details involving grounding for patient equipment and areas on plans. Standard Details may be obtained at http:/www.va/gov/facmgt/standard/details-elec.asp. 3.2 INACCESSIBLE GROUNDING CONNECTIONS Make grounding connections, which are buried or otherwise

25、normally inaccessible (except connections for which periodic testing access is required) by exothermic weld. 3.3 SECONDARY EQUIPMENT AND CIRCUITS A. Main Bonding Jumper: Bond the secondary service neutral to the ground bus in the service equipment. B. Metallic Piping, Building Steel, and Supplementa

26、l Electrode(s): 1. Provide a grounding electrode conductor sized per NEC between the service equipment ground bus and all metallic water and gas pipe Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-10-06M 27 05 26 - 5 systems, building steel, and sup

27、plemental or made electrodes. Jumper insulating joints in the metallic piping. All connections to electrodes shall be made with fittings that conform to UL 467. 2. Provide a supplemental ground electrode and bond to the grounding electrode system. F. Conduit Systems: 1. Ground all metallic conduit s

28、ystems. All metallic conduit systems shall contain an equipment grounding conductor. 2. Non-metallic conduit systems shall contain an equipment grounding conductor, except that non-metallic feeder conduits which carry a grounded conductor from exterior transformers to interior or building-mounted se

29、rvice entrance equipment need not contain an equipment grounding conductor. 3. Conduit containing only a grounding conductor, and which is provided for mechanical protection of the conductor, shall be bonded to that conductor at the entrance and exit from the conduit. G. Feeders and Branch Circuits:

30、 Install equipment grounding conductors with all feeders and power and lighting branch circuits. H. Boxes, Cabinets, Enclosures, and Panelboards: 1. Bond the equipment grounding conductor to each pullbox, junction box, outlet box, device box, cabinets, and other enclosures through which the conducto

31、r passes (except for special grounding systems for intensive care units and other critical units shown). 2. Provide lugs in each box and enclosure for equipment grounding conductor termination. 3. Provide ground bars in panelboards, bolted to the housing, with sufficient lugs to terminate the equipm

32、ent grounding conductors. J. Receptacles shall not be grounded through their mounting screws. Ground with a jumper from the receptacle green ground terminal to the device box ground screw and the branch circuit equipment grounding conductor. M. Raised Floors: Provide bonding of all raised floor comp

33、onents. /See details on the drawings. / 3.4 CORROSION INHIBITORS When making ground and ground bonding connections, apply a corrosion inhibitor to all contact surfaces. Use corrosion inhibitor appropriate for protecting a connection between the metals used. Provided by IHSNot for ResaleNo reproducti

34、on or networking permitted without license from IHS-,-,-10-06M 27 05 26 - 6 3.5 CONDUCTIVE PIPING A. Bond all conductive piping systems, interior and exterior, to the building to the grounding electrode system. Bonding connections shall be made as close as practical to the equipment ground bus. B. I

35、n operating rooms and at intensive care and coronary care type beds, bond the gases and suction piping, at the outlets, directly to the room or patient ground bus. 3.6 TELECOMMUNICATIONS SYSTEM A. Bond telecommunications system grounding equipment to the electrical grounding electrode system. B. Fur

36、nish and install all wire and hardware required to properly ground, bond and connect communications raceway, cable tray, metallic cable shields, and equipment to a ground source. C. Ground bonding jumpers shall be continuous with no splices. Use the shortest length of bonding jumper possible. D. Pro

37、vide ground paths that are permanent and continuous with a resistance of 1 ohm or less from raceway, cable tray, and equipment connections to the building grounding electrode. The resistance across individual bonding connections shall be 10 milli ohms or less. E. Below-Grade Grounding Connections: W

38、hen making exothermic welds, wire brush or file the point of contact to a bare metal surface. Use exothermic welding cartridges and molds in accordance with the manufacturers recommendations. After welds have been made and cooled, brush slag from the weld area and thoroughly cleaned the joint area.

39、Notify the Resident Engineer prior to backfilling any ground connections. F. Above-Grade Grounding Connections: When making bolted or screwed connections to attach bonding jumpers, remove paint to expose the entire contact surface by grinding where necessary; thoroughly clean all connector, plate an

40、d other contact surfaces; and apply an appropriate corrosion inhibitor to all surfaces before joining. G. Bonding Jumpers: 1. Use insulated ground wire of the size and type shown on the Drawings or use a minimum of 16 mm (6 AWG) insulated copper wire. 2. Assemble bonding jumpers using insulated grou

41、nd wire terminated with compression connectors. Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-10-06M 27 05 26 - 7 3. Use compression connectors of proper size for conductors specified. Use connector manufacturers compression tool. H. Bonding Jumper

42、 Fasteners: 1. Conduit: Fasten bonding jumpers using screw lugs on grounding bushings or conduit strut clamps, or the clamp pads on push-type conduit fasteners. When screw lug connection to a conduit strut clamp is not possible, fasten the plain end of a bonding jumper wire by slipping the plain end

43、 under the conduit strut clamp pad; tighten the clamp screw firmly. Where appropriate, use zinc-plated external tooth lockwashers. 2. Wireway and Cable Tray: Fasten bonding jumpers using zinc-plated bolts, external tooth lockwashers, and nuts. Install protective cover, e.g., zinc-plated acorn nuts o

44、n any bolts extending into wireway or cable tray to prevent cable damage. 3. Ground Plates and Busbars: Fasten bonding jumpers using two-hole compression lugs. Use tin-plated copper or copper alloy bolts, external tooth lockwashers, and nuts. 4. Unistrut and Raised Floor Stringers: Fasten bonding ju

45、mpers using zinc-plated, self-drill screws and external tooth lockwashers. 3.7 COMMUNICATION ROOM GROUNDING A. Telecommunications Ground Busbars: 1. Provide communications room telecommunications ground busbar hardware at 950 mm (18 inches) at locations indicated on the Drawings. 2. Connect the tele

46、communications room ground busbars to other room grounding busbars as indicated on the Grounding Riser diagram. B. Telephone-Type Cable Rack Systems: aluminum pan installed on telephone-type cable rack serves as the primary ground conductor within the communications room. Make ground connections by

47、installing the following bonding jumpers: 1. Install a 16 mm (6 AWG) bonding between the telecommunications ground busbar and the nearest access to the aluminum pan installed on the cable rack. 2. Use 16 mm (6 AWG) bonding jumpers across aluminum pan junctions. C. Self-Supporting and Cabinet-Mounted

48、 Equipment Rack Ground Bars: 1. When ground bars are provided at the rear of lineup of bolted together equipment racks, bond the copper ground bars together using solid copper splice plates supplied by the ground bar manufacturer. Provided by IHSNot for ResaleNo reproduction or networking permitted

49、without license from IHS-,-,-10-06M 27 05 26 - 8 2. Bond together nonadjacent ground bars on equipment racks and cabinets with 16 mm (6 AWG) insulated copper wire bonding jumpers attached at each end with compression-type connectors and mounting bolts. 3. Provide a 16 mm (6 AWG) bonding jumper between the rack and/or cabinet ground busbar and the aluminum pan of an ove