URD Transformers

3.5 2 Reviews SKU: TDURD00CENDuration: 60 Minutes

The purpose of this course is to teach the basic principles involved in detecting a transformer problem and to illustrate disconnecting, replacing, and reconnecting a faulted subsurface transformer. Basic troubleshooting techniques are presented using an example in which a subsurface residential transformer has caused a power outage. Techniques for energizing and de-energizing are illustrated. At the conclusion of this course, participants should be able to explain how to use the process of elimination to determine the cause of a residential power outage. They should be able to apply this process to locate the cause of a residential power outage. They should also know how to use diagrams to locate circuits, transformers, and houses, and know how to plan a logical search for the cause of an outage.

Course Details


Training Time: 60 minutes

Compatibility: Desktop Only

Based on: Industry Standards and Best Practices

Languages: English

Learning Objectives

  • Verifying the Power Outage
  • Use diagrams to locate the transformer(s) that feeds houses reporting a power outage.
  • Determine if houses reporting power outages are actually not getting power.
  • Determine if a problem in the primary circuit is the cause of the power outage.
  • Identifying a URD System Fault
  • Use diagrams to find a particular transformer in an underground residential distribution (URD) system.
  • Take a voltage reading of a transformer's secondary output.
  • Explain, with a schematic diagram, how a blown fuse can cause a transformer to have no secondary output even though it is receiving primary power.
  • Explain, with a diagram, how to de-energize a transformer without interrupting power to customers fed by other transformers in the circuit.
  • Isolating a URD Transformer
  • Use a primary schematic and a construction print (or similar system drawing) to find a tie point.
  • Make a tie.
  • Isolate a suspected faulty transformer.
  • Test a transformer and its primary cables to make sure that they are de-energized.
  • Testing a URD Transformer
  • Safely remove a transformer fuse for testing.
  • Install a new fuse in a URD transformer.
  • Re-energize a URD transformer.
  • Disconnect secondary cables.
  • Disconnecting a URD Transformer
  • Install grounds on primary cables.
  • Remove primary cables from a transformer.
  • Disconnect the neutrals and the case ground from a URD transformer.
  • Obtain information necessary to order a replacement URD transformer.
  • Recognize various types of URD transformers.
  • Replacing URD Transformer
  • Install a replacement URD transformer.
  • Test the replacement transformer for proper operation.
  • Restore transformers and cables on either side of the replacement transformer to their original conditions.
  • Disconnect the tie point.

Customer Reviews




Nelson M. Verified Customer


Good info, lots of practical stuff. Not a clear description of feedthrough bushings and exactly why

“Good info, lots of practical stuff. Not a clear description of feedthrough bushings and exactly why these are necessary. This crashes IE numerous times but I stuck with it because I wanted the info.”

ROBERT D. Verified Customer

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