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HomeMy WebLinkAbout260526 - GROUNDING AND BONDING FOR ELECTRICAL SYSTEMS.THE KENT 26 05 26 - 1 THE KENT Issue Date 05.09.18 GROUNDING AND BONDING FOR ELECTRICAL SYSTEMS THE KENT SECTION 26 05 26 - GROUNDING AND BONDING FOR ELECTRICAL SYSTEMS PART 1 - GENERAL 1.01 SUMMARY A. This Section includes methods and materials for grounding systems and equipment, plus the following special applications: 1. Power system grounding. 2. Electrical equipment and raceway grounding and bonding. 3. Grounding for communications systems grounding as specified in Section 27 05 00. 4. Grounding for electronic safety and security systems grounding as specified in Section 28 05 00. 1.02 RELATED DOCUMENTS A. Drawings and general provisions of the Contract, including General and Supplementary Conditions and Division 01 Specification Sections, apply to this Section. B. Section 26 05 00 - Basic Electrical Requirements. C. Section 27 05 00 - Communication Systems Electrical Requirements. D. Section 28 05 00 – Electronic Safety and Security Systems Electrical Requirements. 1.03 REFERENCES A. Review the Drawings and all sections of the Specifications for equipment furnished by other Contractors and the Owner throughout the entire project. B. See references noted in Specification Section 26 05 00, Paragraph 1.03. C. NFPA 70. D. IEEE 1100-1999 (Emerald Book) – IEEE Recommended Practice for Powering and Grounding Electronic Equipment. E. NECA 331-2004 – Building and Service Entrance Grounding and Bonding. F. BICSI J-STD-607-A – Commercial Building Grounding and Bonding Requirements for Telecommunications. 1.04 SYSTEM DESCRIPTION A. Provide complete grounding and bonding system as indicated in the Contract Documents. THE KENT 26 05 26 - 2 THE KENT Issue Date 05.09.18 GROUNDING AND BONDING FOR ELECTRICAL SYSTEMS THE KENT 1.05 SUBMITTALS A. Submit shop drawings and product data under provisions of Division 01 and Section 26 05 00. B. Product Data: For each type of product indicated. C. Other Informational Submittals: Plans showing dimensioned as-built locations of grounding features specified in Part 3 "Field Quality Control" Article, including the following: 1. Ground rods. D. Qualification Data: For testing agency and testing agency's field supervisor. E. Operation and Maintenance Data: For grounding to include the following in emergency, operation, and maintenance manuals: 1.06 QUALITY ASSURANCE A. Provide complete grounding system in accordance with NFPA 70 and as supplemented by this specification. B. Electrical Components, Devices, and Accessories: Listed and labeled as defined in NFPA 70, Article 100, by a testing agency acceptable to authorities having jurisdiction, and marked for intended use. C. Comply with UL 467 for grounding and bonding materials and equipment. 1.07 DELIVERY, STORAGE AND HANDLING A. Deliver, store and handle materials in accordance with Section 26 05 00. 1.08 PROJECT CONDITIONS A. Verify that soil conditions will be suitable for earthing connections prior to installation. 1.09 SEQUENCING AND SCHEDULING A. Sequence and Schedule work in accordance with Section 26 05 00. 1.10 WARRANTY A. Warranty in Accordance with requirements of Division 01 and Section 26 05 00. PART 2 - PRODUCTS 2.01 MANUFACTURERS A. Grounding Insulated Bushings: O-Z/Gedney Company B. Ground Clamps: Thomas & Betts. THE KENT 26 05 26 - 3 THE KENT Issue Date 05.09.18 GROUNDING AND BONDING FOR ELECTRICAL SYSTEMS THE KENT C. Conduit Hub: Thomas & Betts. D. Exothermic Welds: Erico International Corp. E. Compression System: Burndy Corp. 2.02 MATERIALS A. Grounding conductor to be #3/0 AWG bare copper. B. Grounding Insulated Bushings for Distribution Panels and Main Switchboards: O-Z/Gedney Company #1GB1204 or approved equal. C. Ground Rods: Steel core, bonded copper-clad type. Minimum of 3/4 inch in diameter and 10 feet in length. D. Ground Clamps: Thomas & Betts #3903, #3904, #3905, #3906, #3907, #3908 and #3909, or approved equal. E. Conduit Hub: Thomas & Betts #3940 or approved equal F. Exothermic Welds: Utilize CADWELD process by Erico International Corp., or approved equal. G. In lieu of exothermic welds: Utilize compression system by Burndy corp. or approved equal. 2.03 CONDUCTORS A. Insulated Conductors: Copper wire or cable insulated for 600 V unless otherwise required by applicable Code or authorities having jurisdiction. B. Bare Copper Conductors: 1. Solid Conductors: ASTM B 3. 2. Stranded Conductors: ASTM B 8. 3. Tinned Conductors: ASTM B 33. 4. Bonding Cable: 28 kcmil, 14 strands of No. 17 AWG conductor, 1/4 in. in diameter. 5. Bonding Conductor: No. 4 or No. 6 AWG, stranded conductor. 6. Bonding Jumper: Copper tape, braided conductors, terminated with copper ferrules; 1-5/8 inches wide and 1/16 inch thick. 7. Tinned Bonding Jumper: Tinned-copper tape, braided conductors, terminated with copper ferrules; 1-5/8 inches wide and 1/16 inch thick. C. Grounding Bus: Rectangular bars of annealed copper, 1/4 by 2 inches in cross section, unless otherwise indicated; with insulators. 2.04 CONNECTORS A. Listed and labeled by a nationally recognized testing laboratory acceptable to authorities having jurisdiction for applications in which used, and for specific types, sizes, and combinations of conductors and other items connected. THE KENT 26 05 26 - 4 THE KENT Issue Date 05.09.18 GROUNDING AND BONDING FOR ELECTRICAL SYSTEMS THE KENT B. Bolted Connectors for Conductors and Pipes: Copper or copper alloy, bolted pressure-type, with at least two bolts. 1. Pipe Connectors: Clamp type, sized for pipe. C. Welded Connectors: Exothermic-welding kits of types recommended by kit manufacturer for materials being joined and installation conditions. 2.05 GROUNDING ELECTRODES A. Ground Rods: Steel core, bonded copper-clad type; 3/4 inch in diameter by10 feet in length. 2.06 SOURCE QUALITY CONTROL A. Performance of grounding system to be verified as indicated below under Part 3 of this Section. PART 3 - EXECUTION 3.01 EXAMINATION A. Verify the following: 1. Verify that water service consists of metallic piping entering the building and that grounding connection is made ahead of any non-metallic water piping within the building. 2. Verify accessibility and suitability of building structural steel for making grounding conductor connections. 3.02 PREPARATION A. Where grounding connections are to be made to building structural steel, clean steel of paint, rust, corrosion and other contamination that would reduce the effectiveness of grounding connections. B. Protect below grade connections from corrosion. C. Protect above grade connections from damage. 3.03 APPLICATIONS A. Conductors: Install stranded conductors for No. 12 AWG and larger, unless otherwise indicated. B. Underground Grounding Conductors: Install bare tinned-copper conductor, No. 3/0 AWG minimum. 1. Bury at least 24 inches below grade. THE KENT 26 05 26 - 5 THE KENT Issue Date 05.09.18 GROUNDING AND BONDING FOR ELECTRICAL SYSTEMS THE KENT C. Grounding Bus: Install in electrical and telephone equipment rooms, in rooms housing service equipment, and elsewhere as indicated. 1. Install bus on insulated spacers 1 inch, minimum, from wall 12 inches above finished floor, unless otherwise indicated. 2. Where indicated on both sides of doorways, route bus up to top of door frame, across top of doorway, down to specified height above floor, and connect to horizontal bus. D. Conductor Terminations and Connections: 1. Pipe and Equipment Grounding Conductor Terminations: Bolted connectors. 2. Underground Connections: Welded connectors, except as otherwise indicated. 3. Connections to Structural Steel: Welded connectors. 3.04 GROUNDING UNDERGROUND DISTRIBUTION SYSTEM COMPONENTS A. Comply with IEEE C2 grounding requirements. 3.05 EQUIPMENT GROUNDING A. Install insulated equipment grounding conductors with all feeders and branch circuits. B. Signal and Communication Equipment: For telephone, alarm, voice and data, and other communication equipment, provide No. 4 AWG minimum insulated grounding conductor in raceway from grounding electrode system to each service location, terminal cabinet, wiring closet, and central equipment location. 1. Service and Central Equipment Locations and Wiring Closets: Terminate grounding conductor on an insulated grounding bar. Size the bar as required to terminate all grounding and bonding conductors. 2. Terminal Cabinets: Terminate grounding conductor on cabinet grounding terminal. 3.06 INSTALLATION A. Circuit Grounding: 1. Provide a dedicated, insulated ground conductor for each circuit or grouped circuits in a common conduit or raceway. B. Equipment and Raceway Grounding: 1. Bond the conduit system to the main service entrance ground bus with full size ground wire. 2. Provide green insulated copper grounding conductor as the equipment grounding means for all electrical equipment and devices unless otherwise indicated. 3. Provide copper grounding conductors and straps as needed to provide continuous grounding paths. 4. Where conduit is used for mechanical protection of a grounding conductor, securely bond the conductor to the conduit at each end. THE KENT 26 05 26 - 6 THE KENT Issue Date 05.09.18 GROUNDING AND BONDING FOR ELECTRICAL SYSTEMS THE KENT 5. Utilize the conduit installation with double bonding locknuts and insulated bushings between all conduit and equipment as equipment grounding means for all electrical devices, unless otherwise noted. 6. Provide grounding insulated bushings for all conduits entering main electricity metering equipment. At each location, connect all bushings together by a continuous copper ground conductor to feeder circuit grounding conductor or conductors. 7. Provide grounding insulated bushings for feeder conduits entering branch panelboards and load center. In each panelboard and load center, connect all grounding insulated bushings together by a continuous copper ground conductor to feeder circuit grounding conductor or conductors. C. Electrical Service Bonding: 1. At the main electrical service entrance bond the service neutral to ground bar or ground bus. D. Grounding Electrode System: 1. Ground the main electrical service entrance to the incoming metallic water service with a grounding electrode conductor sized in accordance with NFPA 70, Table 250.66. Install a bonding jumper around the water meter the same size as the grounding electrode conductor. Supplement this underground water pipe with a ground rod triangle. 2. Supplement the grounding system with the supplementary grounding electrodes described in NFPA 70, Article 250.52(A)(1), (2), (3) and (4), where available. Connect the service entrance disconnects to this supplementary grounding electrode with a grounding electrode conductor sized in accordance with NFPA 70, Table 250.66. 3. Where the Power Company does not furnish primary transformation or grounding of a grounded system, provide sufficient ground rods near the transformer. Ground the transformer neutral to these ground rods with a #3/0 copper grounding electrode conductor. 4. Bond all building steel structure to the electrical system ground. Providing bonding jumpers as necessary to bond all building steel together to be electrically continuous. E. Grounding Electrode System Connections: 1. Exothermically weld all grounding system connections, except for building distribution and branch circuit conduits. Grounding connections of this type include, but not limited to: a. Cable to cable connections such as tees, splices and X's. b. Structure to ground connections including permanent types, as well as disconnectable lug connections. Disconnects are to use two boltable lugs; one welded to the structure and the other welded to the end of the ground lead. c. Ground rod connections such as those between rod and grounding conductor and splices of deep-driven rods. d. Structure to structure bonding such as across non-welded structural joints and between reinforcing bars. THE KENT 26 05 26 - 7 THE KENT Issue Date 05.09.18 GROUNDING AND BONDING FOR ELECTRICAL SYSTEMS THE KENT F. Communication Systems Grounding: 1. Provide all materials, equipment, and labor for communications systems grounding as specified in Section 27 05 00. 2. Provide a #6 AWG copper grounding wire from the telephone company cable termination location to the main service entrance ground bus. Install in conduit for mechanical protection. G. Electronic Safety and Security Systems Grounding: 1. Provide all materials, equipment, and labor for electronic safety and security systems grounding as specified in Section 28 05 00. H. Grounding Conductors: Route along shortest and straightest paths possible, unless otherwise indicated or required by Code. Avoid obstructing access or placing conductors where they may be subjected to strain, impact, or damage. I. Ground Rods: Drive rods until tops are 2 inches below finished floor or final grade, unless otherwise indicated. 1. Interconnect ground rods with grounding electrode conductor below grade and as otherwise indicated. Make connections without exposing steel or damaging coating, if any. J. Bonding Straps and Jumpers: Install in locations accessible for inspection and maintenance, except where routed through short lengths of conduit. 1. Bonding to Structure: Bond straps directly to basic structure, taking care not to penetrate any adjacent parts. 2. Bonding to Equipment Mounted on Vibration Isolation Hangers and Supports: Install so vibration is not transmitted to rigidly mounted equipment. 3. Use exothermic-welded connectors for outdoor locations, but if a disconnect-type connection is required, use a bolted clamp. K. Grounding and Bonding for Piping: 1. Metal Water Service Pipe: Install insulated copper grounding conductors, in conduit, from building's main service equipment, or grounding bus, to main metal water service entrances to building. Connect grounding conductors to main metal water service pipes, using a bolted clamp connector or by bolting a lug-type connector to a pipe flange, using one of the lug bolts of the flange. Where a dielectric main water fitting is installed, connect grounding conductor on street side of fitting. Bond metal grounding conductor conduit or sleeve to conductor at each end. 2. Water Meter Piping: Use braided-type bonding jumpers to electrically bypass water meters. Connect to pipe with a bolted connector. 3. Bond each aboveground portion of gas piping system downstream from equipment shutoff valve. L. Grounding for Steel Building Structure: Install a driven ground rod at base of each corner column and at intermediate exterior columns at distances not more than 60 feet apart. THE KENT 26 05 26 - 8 THE KENT Issue Date 05.09.18 GROUNDING AND BONDING FOR ELECTRICAL SYSTEMS THE KENT 3.07 FIELD QUALITY CONTROL A. Perform the following tests and inspections and prepare test reports: 1. After installing grounding system but before permanent electrical circuits have been energized, test for compliance with requirements. 2. Test completed grounding system at each location where a maximum ground- resistance level is specified, at service disconnect enclosure grounding terminal. Make tests at ground rods before any conductors are connected. a. Measure ground resistance not less than two full days after last trace of precipitation and without soil being moistened by any means other than natural drainage or seepage and without chemical treatment or other artificial means of reducing natural ground resistance. b. Perform tests by fall-of-potential method according to IEEE 81. B. Report measured ground resistances that exceed the following values: 1. Power and Lighting Equipment or System with Capacity 500 kVA and Less: 1> ohms. 2. Power and Lighting Equipment or System with Capacity 500 to 1000 kVA: 5 ohms. 3. Substations and Pad-Mounted Equipment: 5 ohms. C. Excessive Ground Resistance: If resistance to ground exceeds specified values, notify Architect promptly and include recommendations to reduce ground resistance. END OF SECTION