concrete encased duct bank with multiple voltages

Concrete encased duct bank with multiple voltages install#
Concrete encased duct bank with multiple voltages code#

Concrete encased duct bank with multiple voltages code#

Reference: Section 142.3, Labor Code and Section 18943(c), Health and Safety Code.ġ. NOTE: Authority cited: Section 142.3, Labor Code. Metallic underground ducts shall be suitably protected from corrosion. A duct bank makes it easier to replace damaged cables between buildings or to add. A duct bank may be alternatively be installed in a utility tunnel. Typical configuration of concrete duct bank (2 rows×4. 2: Where it is impractical to obtain the depth of cover specified, the depth shall be permitted to be reduced, provided that the duct has sufficient strength itself or adequate protection is installed above the duct to prevent damage to the duct system by any surface traffic. An assembly of underground conduits, often called a duct bank, may either be directly buried in the earth or encased in concrete, sometimes with a reinforcing rebar to aid against shear forces. Deformation behavior and damage analysis of underground high-voltage cable duct bank encased by concrete. Existing, concrete encased high voltage duct banks and other active. 1: Direct buried conduits to contain cables for series street lighting circuits operating at less than 7,500 volts shall be installed at a depth of at least 24 inches below the surface under which they are located.ĮXCEPTION: No. concrete-encased conduit duct banks within a major maintenance rail yard. A lesser depth is permitted for ducts containing cables operating at 35,000 volts or less, if the duct is rigid metallic conduit, Schedule 80 PVC conduit, or equivalent, or if the duct has a layer of concrete at least 3 inches thick above the duct.ĮXCEPTION: No. Underground ducts of rigid metallic steel conduit, Schedule 80 PVC conduit, or equivalent, containing cables operating at a potential above 35,000 volts, shall be installed at a depth of at least 36 inches.

Concrete encased duct bank with multiple voltages install#

Install warning tape 12 above concrete-encased duct bank. Per NEC, Article 700.10.D.1, feeder conductors that are a part of the EPSS, emergency systems in certain occupancies such as hospitals, must be protected against fire by being installed in spaces that are fully protected by an. 2), the following topics should be explored and evaluated to determine their relevance to the design. Underground conductors that are part of the EPSS distribution should be installed in concrete-encased duct banks. When designing large underground electrical duct banks (Fig. High-Voltage Electrical Safety OrdersĪrticle 19. Use above ground load break centers for all terminations, splices or taps. Duct-Bank Grounding Conductor: Bury 12 inches above duct bank when indicated as part of duct-bank installation. Typical concrete-encased duct bank detail highlighting the evaluated design considerations outlined in this article.