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Underground Residential Distribution Transformers - Instant Video



This 49-minute video covers the basic principles involved in detecting a transformer problem, how to disconnect, replace, and reconnect 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.Explains how to use the process of elimination to determine the cause of a residential power outage and how to use this process to locate the cause of a residential power outage. Shows how to use diagrams to locate circuits, transformers, and houses, and know how to plan a logical search for the cause of an outage.

Training Sessions

Verifying the Power Outage – 6 minutes
Uses diagrams to locate the transformer, or transformers, that feeds houses reporting a power outage. Determines if residential customers reporting power outages are actually not getting power. Determines if a problem in the primary circuit is the cause of a power outage.

Identifying a URD System Fault – 7 minutes
Uses diagrams to find a particular transformer in a URD system. Takes a voltage reading of a transformer’s secondary output. Explains, with a schematic diagram, how a blown fuse could cause a transformer to have no secondary output even though it is receiving primary power. Explains, 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 – 9 minutes
Covers how to: 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, and test a transformer and its primary cables to make sure that they are de-energized.

Testing a URD Transformer – 7 minutes
Explains how to: safely remove a transformer fuse for testing, install a new fuse in a URD transformer, re-energize a URD transformer, and disconnect secondary cables.

Disconnecting a URD Transformer – 10 minutes
Covers how to: 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, and recognize various types of URD transformers.

Replacing a URD Transformer – 8 minutes
Explains how to: 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, and disconnect the tie point.

Item Code: URT-IV

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