Electrical Engineering Standards

Review Design Standards General Statements before utilizing this web page.

On this page:
Building Codes & Industry Standards
Denver Service Center (DSC) Requirements
National Park Service (NPS) Requirements

Building Codes & Industry Standards

  • EIA/TIA Standards 568 & 569
  • IEEE - Standards
  • IESNA 10th Edition Illuminating Engineers Society of North America
  • NESC National Electrical Safety Code 2012
  • NFPA Codes and Standards - see Fire Protection Engineering Standards
  • UL - Underwriters Laboratories

Denver Service Center (DSC) Requirements


  • Site specific, in general Schedule 40 PVC for underground.
  • Minimum branch circuit conduit size = 3/4".
  • Provide conduit for all wiring (minimum size 3/4").
  • The use of non-metallic conduit or tubing is not allowed in interior dry locations unless required by code.
  • A separate equipment grounding conductor, sized per NEC requirements, shall be routed in all conduits.

Equipment and Materials

  • Listed and labeled as defined in NEC Article 100 for application.

Load Requirements

  • NEC 2014
  • 25% minimum spare capacity typical for future expansion.

Overcurrent Protection

  • Fully rated - Series rated is not desired.
  • Breakers preferred for reset capability (sizes 15 amperes or greater).
  • Fuse selection shall comply with NEC requirements and equipment manufacturers recommendations.

Power Wiring

  • Underground - THWN / XHHW
  • No MC or AC type cabling in walls in new construction.
  • No surface mounted MC or AC type cabling where rigid raceway can be used.
  • Copper conductors
  • Copper Buswork


  • EIA/TIA Standards, see above.
  • Cat 6 Cabling - (2) per 3/4" conduit; (1) Data, (1) Voice per each voice / data outlet (typical). Terminate all conductors.
  • Telephone Service Entrance (Demarcation Point) - Meet local phone company requirements.
  • A/E shall query Park for any additional IT, telecom or data system requirements.


  • Coordinate with utility companies as early as possible.
  • Underground distribution as much as possible.
  • NPS prefers not to own and operate utilities.
  • TVSS Protection on all Service Entrances.

National Park Service (NPS) Requirements

NPS Management Policies 2006 - The Guide to Managing the National Park System

Director's Orders (DOs)

Handbooks, Reference Manuals (RMs), Strategies, Plans, & other Professional Materials



Last updated: June 14, 2018