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<br />, ' <br /> <br />(e) Enclosures for Grounding Electrode Conductors. Metal enclosures for grounding electrode conductors <br />shall be electrically continuous from the point of attachment to cabinets or equipment to the grounding <br />electrode, and shall be securely fastened to the ground clamp or fitting. Metal enclosures that are not physically <br />continuous from cabinet or equipment to the grounding electrode shall be made electrically continuous by <br />bonding each end to the grounding conductor. Where a raceway is used as protection for a grounding conductor, <br />the installation shall comply with the requirements of the appropriate raceway article.!=wn:nC,allJ <br /> <br />. . 250-66. Size of Alternating-Current Grounding Electrode Conductor <br /> <br />The size of the grounding electrode conductor of a grounded or ungrounded ac system shall not be less than <br />given in Table 250-66, except as permitted in (a) through (c). <br /> <br />Table 250-66. Grounding Electrode Conductor for Alternating-Current Systems <br /> <br />Size of Largest <br />Service-Entrance Conductor <br />or Equivalent Area for <br />Parallel Conductors 1 <br /> <br />Size of Grounding Electrode <br /> <br />Conductor <br /> <br />Copper <br /> <br />Aluminum or <br />Copper-Clad <br />Aluminum <br /> <br /> Aluminum or <br /> Copper-Clad <br />Copper Aluminum 2 <br />8 6 <br />6 4 <br />4 2 <br />2 1/0 <br /> <br />2 or smaller <br /> <br />1/2 or smaller <br />2/0 or 3/0 <br />4/0 or 250 <br />kcmil <br />Over 3/0 Over 250 kcmil <br />through 350 through 500 <br />kcmil kcmil <br />Over 350 kcmil Over 500 kcmil <br />through 600 through 900 <br />kcmil kcmil <br />Over 600 kcmil Over 900 kcmil <br />through 1100 through 1750 <br />kcmil kcmil <br />Over 1'100 Over 1750 <br />kcmil kcmil <br /> <br />1 or 1/0 <br /> <br />2/0 or 3/0 <br /> <br />1/0 <br /> <br />3/0 <br /> <br />2/0 <br /> <br />4/0 <br /> <br />3/0 <br /> <br />250 kcmil <br /> <br />Notes: <br />1. Where multiple sets of service-entrance conductors are used as permitted in Section 230-40, Exception No.2, the equivalent <br />size of the largest service-entrance conductor shall be determined by the largest sum of the areas of the corresponding conductors <br />of each set. <br />2. Where there are no service-entrance conductors, the grounding electrode conductor size shall be determined by the equivalent <br />size of the largest service-entrance conductor required for the load to be served. <br /> <br />1 This table also applies to the derived conductors of separately derived ac systems. <br />2 See installation restrictions in Section 250-64(a). irE~t'aTv. <br />FPN: See Section 250-24(b) for size ofac system conductor brought to service equipment. <br /> <br />(a) Connections to Made Electrodes. Where the grounding electrode conductor is connected to made <br />