Concrete Encased Duct Bank Design

Underground concrete encased electric conduit duct banks shall consist of type db 60 polyvinyl chloride pvc conduit rated for 90 c cable and meeting nema standard tc 6 and astm f 512 for underground applications.

Concrete encased duct bank design.

Minimum concrete coverage on left. Duct bank width. A metallic backed marking tape shall be installed 12 above all underground conduits and duct banks. Load density is significant.

Concrete encasement shall extend a minimum of 76mm 3 inches from any conduit in the bank to the outside surface. For concrete encased conduits use manufactured pvc spacers and mounts for support and spacing of the conduits. Volume of duct bank. Minimum concrete coverage on right.

Reinforce concreteencased duct banks where they cross disturbed earth and where indicated. 554 2 ft 3 20 5 yd 3. Boxes and not concrete manholes. From gradeto the top of duct bank shall be a minimum of 610 mm 24 inches.

Do not use concrete blocks or other means to support and space conduits that are to receive concrete encasement. Cables installed in concrete encased pvc duct this type of system is typically used in urban areas where. Conduit stub ups shall be rigid steel. Concentration of circuits via the same route are planned or expected.

Minimum concrete coverage on bottom. Use walls of trench to form side walls of duct bank where soil is self supporting and concrete. Arrange reinforcing rods and ties without forming conductive or magnetic loops around ducts or duct groups.