specifications - FAACO - Federal Aviation Administration Contract ...

FTWIC-2235June 20094/0 AWG stranded copper cable. Connections shall be by exothermic welds. Thegrounding electrode conductor for the electric service, sized in accordance with the NEC,shall not be smaller than No. 6 AWG and shall be connected to a ground rod in the earthelectrode system with an exothermic weld. All underground metallic pipes, tanks, andtelephone ground shall be connected to the earth electrode system by a copper cable nosmaller than No. 2 AWG. Exothermic welds shall not be used where hazards exist suchas near fuel tanks.K. All exposed non-current-carrying metallic parts of electrical and mechanical equipment,including metallic raceway systems, piping, steel columns, and other structural membersand neutral conductors of the wiring system shall be grounded as required by theNational Electrical Code and this specification. The grounding conductor shall be greencolor coded or bare, sized as specified or indicated, and if not specified or indicated, itshall be in accordance with Article 250 of the National Electrical Code. Grounding lugs,connectors and other components shall comply with the National Electrical Code.L. The grounding electrode conductor shall be bare copper unless otherwise indicated andshall be sized as shown on the contract drawings, or where not shown, shall be sized inaccordance with the applicable part of the National Electrical Code except that it shall notbe sized smaller than No. 6 AWG. This conductor shall be connected to the groundedconductor (neutral) in the service disconnecting means and shall extend to the groundingelectrode directly, in one continuous run. Where installed in metal conduit that is notelectrically continuous to the grounding electrode, the grounding electrode shall bebonded to the open ends of the conduit.M. The grounding electrode shall be installed as shown on the contract drawings, but in nocase shall it consist of less than the quantity shown. The rods shall be 3/4 inch by 10 feetcopper clad steel, and shall be the sectional type. The top of the ground rod shall be aminimum of 12 inches below grade. Where a metallic water piping system exists, thewater pipe shall be connected to the above specified grounding electrode with the samesize conductor as that which connects the three or more grounds together. Thisconnection shall be made whether or not shown on the contract drawings unlessprohibited by the local utility companies.N. The maximum resistance of the facility grounding electrode shall not exceed 5 ohmsunless a lower resistance is indicated on the drawings, in which case the value shown onthe drawings shall be used. All underground conductor to conductor connections, andconductor to ground rod connections shall be made by the exothermic weld process.END OF SECTION16450-7