E315 - Circuit Breaker Maintenance

4½ days - 2.9 Continuing Education Units Awarded

This course is designed to present some of the more common aspects of low and medium voltage switchgear maintenance. It must be understood that there is an incredible variety of equipment used on low and medium switchgear today. Switchgears play an important role in the distribution and control of electrical power in manufacturing or power plant and in a utility distribution system. Negligent maintenance practices can lead to power system inefficiency and loss of system reliability. 

This course instructs on mechanical maintenance practices and the conducting of electrical tests.  Safety and the benefits of preventive maintenance is stressed throughout the course presentation.

Topical Outline includes: Low and Medium Voltage Switchgear, Types of Breakers, Arc Interruption, Insulation Resistance Testing, Power Factor Testing, Instrument Transformer Testing, Low Voltage Protective Devices, Circuit Breaker Construction, Air Circuit Breakers, and Vacuum Circuit Breakers.

COURSE OBJECTIVES
Upon successful completion of this course, the student should be able to:

1. Discuss standard switchgear terminology.
2. Discuss the general classifications of circuit breakers.
3. Discuss circuit breaker construction.
4. Discuss circuit breaker ratings.
5. Discuss arcs and arc interruption
6. Discuss insulation resistance testing.
7. Discuss power factor testing
8. Discuss transformer testing.
9. Discuss protective devices
10. Discuss the operation of air circuit breakers.
11. Discuss the operation of vacuum circuit breakers
12. Discuss the operation of gas circuit breakers
13. Discuss circuit breaker maintenance

COURSE OUTLINE

1. Introduction: Voltage Convention, Low and Medium Voltage Switchgear, Types of Breakers, Arc Interruption
2. Insulation Resistance Testing: Factors Affecting Insulation Resistance, Temperature Correction, Insulation Resistance Testing, Circuit Breaker Insulation Resistance Testing, High Potential Testing
3. Power Factor Testing: Advantages, Test Procedure, Data Interpretation
4. Instrument Transformer Testing: Polarity Testing, Turns Ratio Testing, Secondary Excitation Testing
5. Low Voltage Protective Devices: Requirements, Time-Current Characteristics, Tripping Devices, Maintenance and Testing
6. Circuit Breaker Construction: Components, Operating Mechanism
7. Air Circuit Breakers: Medium Voltage, Low Voltage
8. Vacuum Circuit Breaker: Vacuum Circuit Breaker Interrupter, Maintenance
9. Gas Circuit Breaker: Discussion, Sulphur Hexaflouride Gas Interruption
10. Circuit Breaker Maintenance and Testing: Maintenance Fundamentals, Initial Tests, Routine Tests, Adjustments, Insulation Resistance Testing, Contact Resistance Tests, High Potential Tests, Power Factor Tests, and Breaker Motion Analysis