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READ AND REMOVE THIS PAGE BEFORE PLACING
THE SPECIFICATION SECTION IN THE CONTRACT

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DIVISION 16:  ELECTRICAL

SECTION 16062 ‑ SECONDARY GROUNDING

USE:	Furnishing and installing grounding systems for secondary electrical distribution service equipment.  

NOTES TO SPECIFIER:

	A.	Options within paragraphs are identified by enclosure in brackets; blank spaces enclosed by brackets [_____] provide for information to be inserted, as appropriate, to individual projects.

	B.	TO AVOID CONFLICTING REQUIREMENTS AND COSTLY MISTAKES, the specifier must edit (delete, substitute or add to the text).  The remaining paragraphs must be renumbered.

	C.	DELETE FOR FINAL COPY: Notes to the Specifier, located between lines of asterisks; all [brackets], underlining, boldface, and italics, within the paragraphs; and this page.  (Open Reveal Codes [alt F3] to do this accurately.)

	D.	To Edit “(Footer B)”: (Corel 8).  ENTIRE FOOTER SHOULD BE BOLDED.  Click in the footer and delete the “Project Name (ftr B)” text and replace it with the Name of the Project (upper and lower case).  Replace date with current MM/YY (WITHOUT BRACKETS).

	E.	The Guide Specifications are intended to be continuously reviewed and revised.  User’s technical comments are appreciated.  Also, other related or similar specification that are written “from scratch” that could benefit others, or other questions can be sent to NSTC A/E Group, ST 110, or call (303) 987-6868.

DRAWING DATA REQUIRED:

REVISIONS OF THIS SECTION:
CSI format, editorial changes 12/01
Metric: Not Applicable
Technical Update: 11/99

SECTION 16062

SECONDARY GROUNDING

PART 1:  GENERAL

1.1	SUMMARY

	A.	Section Includes:  [Furnishing] [and] [installing] grounding-system equipment for secondary electrical-distribution services and equipment.

1.2	SUBMITTALS

	A.	General:  Submittals shall be according to [Section 01009 - General Information and Requirements.] [Section 01330 ‑ Submittal Procedures.] [Section 01365 - Certificates of Conformance.]

	B.	Manufacturer's Literature:  Submit 5 copies of the manufacturer's technical data for the grounding system equipment to be used on this project, including grounding conductors, ground rods and grounding terminals and connectors.

1.3	QUALITY ASSURANCE

	A.	Labeling Requirements:  Grounding-system equipment shall be Underwriters Laboratories, Inc. (UL) listed and labeled.  UL listing and labeling will not be required if it can be shown that grounding system equipment meets the requirements of another nationally recognized testing laboratory (NRTL).

PART 2:  PRODUCTS

2.1	MATERIALS

	A.	General:  Grounding-system components shall be constructed of the manufacturer's standard materials, as listed in published product information; types and sizes shall be as indicated or as required for the installation.

	B.	Conductor Material:  Soft‑drawn, annealed copper.

	C.	Conductor Type:  Solid in sizes No. 8 AWG and smaller and stranded in sizes No. 6 AWG and larger.

	D.	Conductor Insulation:  Bare or with green insulation as specified for Conductors for General Wiring in Section 16120 ‑ Conductors and Cables.

E.	Braided Bonding Jumpers:  Copper tape, braided No. 30 AWG bare copper wire, terminated with copper ferrules.

F.	Bonding straps:  Soft copper, 0.05 inch (1 mm) thick and 2 inches (50 mm) wide, except as indicated.

	G.	Ground Rod Material:  Copper-jacketed steel (copperweld).

	H.	Ground Rod Size:  Not less than 3/4‑inch diameter by 10-feet long.

	I.	Ground Rod Type:  Sectional.

	J.	For Connection to Rods and Pipes up to One Inch OD:  Two‑bolt, saddle‑type pipe clamp with attached conduit hub and conductor lug.

	K.	Thermic Connection:  For ground wire connection to solid ground rod, thermic connection may be substituted for pipe clamp specified above.

	L.	For Connection to Pipes up to 12 Inches OD:  U-bolt and yoke with attached conduit hub and conductor lug.

	M.	For Connection to a Flat Surface:  Compression or screw clamp terminal lug as described in Section 16120 - Conductors and Cables.

	N.	Ground Buses For Panelboards:  As required in Section 16138 ‑ Cabinets and Enclosures.

PART 3:  EXECUTION

3.1	INSTALLATION

	A.	General:  Install grounding-system components as indicated or as necessary, complying with the manufacturer's written instructions, applicable requirements of codes and standards, and according to recognized industry practices.

	B.	Service Grounding:  Shall be according to Article 250 of the NFPA 70.

	C.	Equipment Grounding:  Make tight metal-to-metal contact between all metallic parts of the raceway system and enclosures to ensure a ground fault current path of the lowest-possible impedance.

	D.	Supplementary Equipment-Grounding Conductors:  Install a grounding conductor, sized according to the NFPA 70 Table 250‑122,  in flexible conduit, in non‑metallic conduits, from the ground terminal on receptacles, and where otherwise indicated.  Connect the ends of grounding conductors to any convenient metallic box or enclosure which is connected to the rigid steel or EMT conduit system.

	E.	Metal Poles Supporting Outdoor Lighting Fixtures:  Ground pole to a grounding electrode in addition to separate equipment grounding conductor run with supply branch circuit.

	F.	Grounding Rods:  Locate a minimum of 1 rod length from each other and at least the same distance from any other grounding electrode.

a.	ab	Drive until tops are 2 inches (50 mm) below finished floor or final grade, except as otherwise indicated.
		2.	Interconnect with other grounding electrode conductors.  Use exothermic welds or grounding clamp connectors, unless otherwise indicated.  Make these connections without damaging copper coating or exposed steel.

G.	ab	Grounding Conductors:  Route along the shortest and straightest paths possible, except as otherwise indicated.  Avoid obstructing access or placing conductors where they may be subjected to strain, impact, or damage.

H.	ab	Metal Water Service Pipe:  Provide insulated copper grounding conductors, sized as indicated, 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 by grounding clamp connectors.  Where a dielectric main water fitting is installed, connect grounding conductor to street side of fitting.  Do not install a grounding jumper across dielectric fittings.  Bond grounding conductor conduit to conductor at each end.

I.	ab	Water Meter Piping:  Use braided type bonding jumpers to electrically bypass water meters.  Connect to pipe with grounding clamp connectors.

J.	ab	Interior Metal:  Bond interior metal piping systems and metal air ducts to equipment grounding conductors of associated pumps, fans, blowers, electric heaters, and air cleaners.  Use braided type bonding straps.

K.	ab	Ufer Ground (Concrete Encased Grounding Electrode):  Fabricate using a minimum of 20 feet of bare copper conductor not smaller than No. 4 AWG.  Where base of concrete foundation is less than 20 feet in length, coil excess conductor within base of concrete foundation.  Bond grounding conductor to reinforcing steel to at least 4 locations, and to anchor bolts.  Extend grounding conductor below grade and connect to building grounding grid or to a grounding electrode external to concrete.

L.	ab	Grounding Bushings:  Where steel conduits terminate without mechanical connection to metallic enclosures, install a grounding bushing on the end of each conduit and connect them to the enclosure with a bare-copper grounding conductor sized according to NEC Table 250‑122 for the largest circuit being connected.  For electrically-noncontinuous conduits which contain only a grounding conductor, bond the conduit and conductor together at both ends by means of grounding bushings.

	M.	Service-Grounding Electrode:  The resistance between the service-grounding electrode and earth shall not be greater than 10 ohms.  When necessary, drive no more than two additional ground rods and interconnect them with the original-grounding electrode to achieve this conductivity requirement.

	N.	Ground Fault Current Path:  The resistance between the service-equipment enclosure and the metallic frame of any connected equipment shall not be greater than 5 ohms.  When necessary, clean and tighten metal‑to‑metal connections or install supplementary-grounding conductors in the ground path to achieve this conductivity requirement.

PART 4:  MEASUREMENT AND PAYMENT
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WHEN A "LUMP SUM" CONTRACT IS USED, DELETE THE TITLE PART 4:  MEASUREMENT AND PAYMENT, AND BOTH ARTICLES FROM THIS SECTION.  MEASUREMENT AND PAYMENT WILL BE ADDRESSED IN PART 4 OF SECTION 01010 -SUMMARY OF WORK.
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4.1	METHOD OF MEASUREMENT

	A.	Units:  The work described in this section will not be measured for payment.

4.2	BASIS OF PAYMENT

	A.	Payment:  No direct payment for the work described under this section will be made.  Consideration for this item shall be included in the bid price for other items of the Contract.

END OF SECTION

SECONDARY GROUNDING
Project Name (ftr B)	[12/01]
16062 -