URD Troubleshooting

Summary

The construction of underground residential distribution systems has increased significantly since its start in the 1960s. Today, many areas require URD systems for new housing developments. As the number of URD systems in use continues to grow, it becomes more and more important for linemen to be able to locate and identify faults quickly so that power can be restored to customers. This 29-minute video describes methods that can be used to troubleshoot two types of problems that may affect URD systems: transformer faults and cable faults.

Training Sessions

Isolating Transformer Faults – 9 minutes Describes the layout of a typical underground residential distribution system. Describes how to troubleshoot a transformer fault in which only the transformer primary fuse is blown. Describes how to troubleshoot a transformer fault in which the riser pole fuse is blown but the transformer primary fuse is intact.

Isolating Cable Faults, Part 1 – 10 minutes Describes how to troubleshoot a cable fault in a system equipped with cable fault indicators. Identifies three common types of cable fault indicators. Describes how to troubleshoot a cable fault by isolating and testing one section of cable at a time starting at the normally open point in the loop. Describes how to troubleshoot a cable fault by isolating and testing one section of cable at a time starting at a blown riser pole fuse.

Isolating Cable Faults, Part 2 – 10 minutes Describes how to troubleshoot a cable fault by re-energizing one section of cable at a time. Describes how the area to be isolated and tested for a cable fault in a URD system can be reduced. Describes the major difference between troubleshooting a transformer fault or a cable fault in a three-phase system and troubleshooting a transformer fault or a cable fault in a single-phase system. Describes how to troubleshoot a cable fault using a radar fault locator.

Support Materials Available

Student workbook, instructor guide.