Course ID
TDC04

COURSE DESCRIPTION

This course discusses the basics of underground transformer operations. It presents problems that arise when operating transformers and discusses troubleshooting techniques and inspection procedures. This course also describes the general characteristics of two basic types of pad-mounted switchgear: oil-immersed disconnect switches and transclosures. This course also describes how pad-mounted switchgear can be used to sectionalize and reroute power in an underground feeder system.

COURSE GOALS

  • Describe the general features of pad-mounted transformers.
  • Describe typical uses for pad-mounted transformers.
  • Identify four pad-mounted voltage problems and describe how to troubleshoot a three-phase transformer for these problems.
  • Describe the general characteristics of oil-immersed disconnect switches and transclosures.
  • Explain how pad-mounted switchgear can be used to sectionalize and reroute power in an underground feeder system.

 

SUBJECTS AND OBJECTIVES

Pad-Mounted Transformers

  • Describe the general construction and features of a pad-mounted transformer.

Pad-Mounted Transformer Installation

  • Describe an installation procedure for a three-phase pad-mounted transformer that includes the following steps: site preparation, transformer installation, and testing.

Troubleshooting a Three-Phase Transformer – Part 1

  • Define “one leg open” and describe its symptoms.
  • Define “ferroresonance” and describe its symptoms.
  • Define “off-ratio winding” and describe its symptoms.
  • Define “open neutral” and describe its symptoms.

Troubleshooting a Three-Phase Transformer – Part 2

  • Describe how the troubleshooting process can be used to isolate the cause of a problem in a three-phase pad-mounted transformer.

Pad-Mounted Switchgear

  • Identify two types of pad-mounted switchgear.
  • Describe the use of pad-mounted switchgear to sectionalize and isolate portions of a URD system.
  • Describe some typical physical and operational checks that can be performed on pad-mounted switchgear.

Pad-Mounted Switchgear Operation

  • Describe the use of pad-mounted switchgear to sectionalize and isolate equipment in an underground feeder system.