INTEGRATED GAS SPACER CABLE

70-213 325-3. Uses Permitted. The Type IGS cable shall be permitted for use underground, including direct burial in the earth, as service-entrance conductors, or as feeder or branch-circuit conductors. 325-4. Uses Not Permitted. The Type IGS cable shall not be used as interior wiring or exposed in contact with buildings. B. Installation 325-11. Bending Radius. Where the coilable nonmetallic conduit and cable is bent for installation purposes or is flexed or bent during shipment or installation, the radii of bends measured to the inside of the bend shall not be less than specified in Table 325-11. Table 325-11. Minimum Radii of Bends Conduit Trade Minimum Size Radii 2 inch 24 inches (610 mm) 3 inch 35 inches (889 mm) 4 inch 45 inches (1.14 m) 325-12. Bends. A run of Type IGS cable between pull boxes or terminations shall not contain more than the equivalent of four quarter bends (360 degrees, total), including those bends located immediately at the pull box or terminations. 325-13. Fittings. Terminations and splices for the Type IGS cable shall be identified as a type that is suitable for maintaining the gas pressure within the conduit. A valve and cap shall be provided for each length of the cable and conduit to check the gas pressure or to inject gas into the conduit. 325-14. Ampacity. The ampacity of the Type IGS cable and conduit shall not exceed values shown in Table 325-14 for single conductor or multiconductor cable. C. Construction Specifications 325-20. Conductors. The conductors shall be solid aluminum rods, laid parallel, consisting of one to nineteen 1/2-inch (12.7-mm) diameter rods. The minimum conductor size shall be 250 kcmil and the maximum size shall be 4750 kcmil. 70-214 NATIONAL ELECTRICAL CODE Table 325-14. Ampacity Type IGS Size kcmil Amperes 250 119 500 168 750 206 1000 238 1250 266 1500 292 1750 315 2000 336 2250 357 2500 376 3000 412 3250 429 3500 445 3750 461 4000 476 4250 491 4500 505 4750 519 325-21. Insulation. The insulation shall be dry kraft paper tapes and a pressurized sulfur hexafluoride gas (SF₆), both approved for electrical use. The nominal gas pressure shall be 20 pounds per square inch gauge (psig) (138 kPa gauge). The thickness of the paper spacer shall be as specified in Table 325-21. Table 325-21. Paper Spacer Thickness Size Thickness kcmil Inches (mm) 250-1000 .040 (1.02) 1250-4750 .060 (1.52) 325-22. Conduit. The conduit shall be an approved medium density polyethylene identified as suitable for use with natural gas rated pipe in 2 inches, 3 inches, or 4 inches trade size. The percent fill dimensions for the conduit are shown in Table 325-22. The size of the conduit permitted for each conductor size shall be calculated for a percent fill not to exceed Table 1, Chapter 9.