Underground Electrical Distribution Fundamentals

Live Streaming Online November 16-17

An EUCI Program

Click Here to register ($1195)

More communities are seeking to underground existing overhead electrical distribution lines for a variety of reasons such as: reliability/storm hardening, visual reasons, new construction requirements and more. This course will review the fundamentals of underground distribution feeder design and operation by providing an in-depth look at underground systems, technology, construction, and operation. This is the ideal course for engineers and project managers new to underground distribution projects or anyone looking for a more in-depth look at underground distribution systems.

Learning Outcomes

  • Expand on the various loop feed configurations used in underground systems
  • Discuss the major material types used, when and why they are used in underground systems
  • Review conductor types, applications and connecting systems used in underground systems
  • List the differences, features, types and applications of distribution transformers
  • Define the various type of pad-mount equipment and their applications
  • Review the design and operation safety requirements for underground systems
  • Discuss the typical fault types and other problematic issues for underground systems



9:10 a.m. – 5:00 p.m.
Course Timing

Loop Feed Configurations

  • Dip Poles
  • Underground Feeders

Major Materials

Dead Front vs. Live Front (Legacy Equipment)

  • Conductor
    • Direct Buried (NESC Part II Sec 35)
    • Installed in Duct
  • Connecting Systems
    • Molded Rubber Products
      • 200a Load Break Elbows
      • 600a Dead Break Connectors
      • Feed thru Parking Bushings and Parking Stands
      • Arresters
      • Cable Splices
  • Distribution Transformers
    • Single and Three Phase
    • Bay-o-net Fuses


9:10 a.m. – 12:00 p.m.
Course Timing

Padmount Equipment

  • Sectionalizing Cabinets
  • Switching Stations
  • Overcurrent Protective Equipment
  • Automatic Throw Over Switchgear
  • Voltage Regulators
  • Capacitor Banks

Safety Considerations

  • Design – NESC 2017 Part II Sections 30 – 39
  • Sec 31 General Requirements
  • Sec 32 Underground Conduit Systems

Operating Underground Distribution Systems

  • Visible Break
  • Grounding