Power Transformer Pressure Relay Testing

Summary

Problems in power transformers cannot always be prevented, but they can be controlled. Protective devices can be used to prevent problems from becoming more serious and causing extensive damage. One type of protective device that is commonly used on a power transformer is a pressure relay.

This 37-minute DVD covers the operation and testing of two basic types of pressure relays: sudden pressure and fault pressure.

Training Sessions

Sudden Pressure Relays – 9 minutes
States the function of a pressure relay in a power transformer. Explains how a sudden pressure relay works. Identifies control components typically associated with a sudden pressure relay. Describes how control components may interact with a sudden pressure relay.

Fault Pressure Relays – 14 minutes
Identifies where a fault pressure relay is typically used. Explains how a fault pressure relay works.

Testing a Sudden Pressure Relay – 13 minutes
States the purpose of testing a sudden pressure relay. Identifies safety precautions to be observed when a sudden pressure relay is tested. Describes a procedure for testing a sudden pressure relay on a de-energized transformer. Describes a procedure for testing a sudden pressure relay on an energized transformer.

Testing a Fault Pressure Relay – 10 minutes
Identifies precautions that should be observed when a fault pressure relay is tested. Describes a procedure for testing a fault pressure relay by applying pressure through the test plug hole. Describes a procedure for testing a fault pressure relay by applying pressure through the bleeder valve.

Support Materials Available

Student workbook, instructor guide.