SECTION 16450 GROUNDING
PART 1 GENERAL
1.1 RELATED REQUIREMENTS
A. Applicable provisions of Division 0 and Division 1 shall govern work in this Section.
1.2 SCOPE
A. Provide all material, labor and incidentals necessary for the completion of this section of the work.
1.3 QUALITY ASSURANCE
A. Follow the requirements of the following regulatory agencies;
1. National Fire Protection Association (NFPA), NFPA-70 - National Electrical Code (NEC) and Wisconsin amendments thereto.
2. Local Codes and Ordinances
1.4 REFERENCE STANDARDS
A. Conform to the standards of the National Electrical Contractors Association (NECA), Standard of Installation.
1.5 SUBMITTALS
A. Ground rod locations.
B. Ground resistance at each ground rod.
C. Soil conditions.
D. Building water service resistance
PART 2 PRODUCTS
2.1 GROUND CLAMPS
A. Ground clamp fittings shall be interlocking clamp type fabricated from high strength corrosion-resistant metal with high strength silicon bronze U-bolt, nuts, and lock washers.
2.2 GROUND RODS
A. Thick copper covering inseparably welded to a strong steel core.
B. ¾ in. diameter minimum
C. Ten feet long minimum
D. Furnish and install up to three rods, positioned in a triangular pattern (spaced 15 feet apart) to achieve 5 ohms or less.
2.3 GROUND WIRES
A. Copper only
B. Size as shown on drawings, or as required by NEC
C. No. 6 AWG minimum
PART 3 EXECUTION
3.1 GENERAL
A. Ground electrical systems and equipment as required by code, utility, local ordinances, and to requirements herein.
B. Install separate code rated grounding conductors to special equipment and activity areas as required by code.
C. Bond all metallic piping systems and service equipment as required by NEC.
D. Cable connections and joints shall be thermo-welded.
3.2 SYSTEM GROUND
A. Attach grounding electrode conductor to point ahead of water meter or service shut-off valve. Grounding electrode conductor shall be permitted to be attached to other grounding electrodes where available in the building as defined in NEC Article 250-81 in lieu of attaching to water service.
B. Water piping system ground shall be augmented by 2 NEC approved grounding electrodes so as to achieve an effective ground resistance as required by code and as shown on the plans. Building steel shall be used where available.
C. Drive ground rods to a depth 4 inches below finished grade.
D. Grounding electrode conductor.
1. Continuous without splice from nearest building grounding electrode. Ground to service equipment.
2. Install bonding jumper around water meter.
3. Install in rigid metal conduit securely fastened to pipe.
4. Attach non-ferrous metal tag to warn against removal.
5. Make connections to ground electrodes with approved molded exothermic weld process.
3.3 EQUIPMENT GROUND
A. Bond metallic conduits, supports, cabinets, and other equipment so ground will be electrically continuous from service to outlet boxes.
B. Install grounding conductor in nonmetallic and flexible conduit to complete equipment ground continuity. Ground wire shall be bonded at equipment and at first junction box of conduit system on line side of flexible conduit to the system.
C. Install grounding conductors to permit shortest and most direct path from equipment to ground. When grounding conductor runs through metallic conduit, bond to conduit at entrance and exit with a bolted clamp.
D. Ground neutral at service-entrance only.
E. Install a separate equipment grounding conductor in each conduit containing feeder conductors.
F. Install a green equipment grounding conductor in all conduits serving receptacles and special purpose outlets.
G. Provide dedicated equipment grounding conductors with all circuits serving isolated ground receptacles. Isolated ground conductors shall have a green jacket with a yellow stripe.
H. Green ground bar in panels: shall be similar to neutral bar, except tinted green and bonded to panel tub.
I. Connections shall be accessible for inspection and checking. No insulation shall be installed over ground connections.
J. Ground connection surfaces shall be cleaned and all connections shall be made so that it is impossible to move them.
K. Attach grounds permanently before permanent building service is energized.
L. Ground metal lighting poles. Install a ground lug on wall of pole directly across from handhole.
M. Attach ground wire neatly and firmly to walls.
3.4 FIELD QUALITY CONTROL
A. Contractor shall make ground resistance measurements. Measure in normally dry conditions, not less than 48 hours after rainfall.
B. Report ground resistance measurement to Engineer within 48 hours of measurement.
END OF SECTION
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