Transformer Troubleshooting
COURSE DESCRIPTION
This course describes basic procedures for troubleshooting various types of transformers and transformer banks. The course begins by examining different types of transformers, transformer connections, and overcurrent and overvoltage devices that are typically used to protect transformers. The program identifies some typical causes of transformer outages and describes some general considerations involved in responding to a trouble call. The dangers associated with and the potential sources of backfeed are also covered. This course demonstrates procedures for isolating and testing single-phase transformers and three-phase transformer banks. The course also describes how to temporarily restore service in single-phase and three-phase applications.
COURSE GOALS
Describe different types of transformers, transformer connections, and overcurrent and overvoltage protective devices.
Identify typical causes of transformer outages.
Describe basic procedures for responding to a trouble call.
Describe potential sources of backfeed.
Describe how to isolate and test single-phase transformers and three-phase transformer banks.
Describe how to temporarily restore service in single-phase and three-phase applications.
SUBJECTS AND OBJECTIVES
Introduction to Transformer Troubleshooting
Describe different types of transformer connections.
Describe the basic differences between CSP transformers and conventional transformers.
Protective Devices
Describe some overcurrent protective devices that are used with transformers.
Describe some overvoltage devices that are used with transformers.
Transformer Problems
Describe typical causes of transformer outages.
Describe general considerations involved in responding to a trouble call.
Describe potential sources of backfeed.
Isolating and Testing Single-Phase Transformers – Part 1
Describe how to isolate and test a typical wye-connected conventional transformer.
Describe special considerations associated with isolating and testing a delta-connected conventional transformer.
Isolating and Testing Single-Phase Transformers – Part 2
Describe how to isolate a typical CSP transformer.
Describe how to test a typical CSP transformer.
Troubleshooting Three-Phase Banks
Identify ways that single-phase transformers can be banked together.
Define the following terms: pole top arcing and sympathetic tripping.
Describe how to isolate and test a typical three-phase transformer bank.
Temporary Service Restoration
Describe one way that temporary service can be restored in a single-phase application.
Describe one way that temporary service can be restored in a three-phase application.