CLAUSE
1.0 Overview
     1.1 Scope
     1.2 Purpose
2.0 References
3.0 Definitions
PART A-FAILURE INVESTIGATION
4.0 Procedure for the Investigation of Circuit Breaker Failures
     4.1 Immediate Action
     4.2 Investigation
     4.3 Investigation Flow Chart
     4.4 Recommended Plan of Action
5.0 Data Collection
     5.1 General Approach
     5.2 Preparation
     5.3 Immediate Investigation
          5.3.1 Electrical Tests
          5.3.2 Tests of Insulating Medium
     5.4 Subsequent

6.0 Failure Analysis
     6.1 General
     6.2 Operating Mechanism
     6.3 Failure due to Degradation of External Solid
          Insulation
     6.4 Failure due to Voltage Transients
     6.5 Failures due to Misapplication
     6.6 Closing Resistor, Capacitor, Current
          Transformer Failure
     6.7 Failure due to Animals
     6.8 Other Causes of Failure
     6.9 Internal Dielectric and Interrupter Failures
          6.9.1 Single Pressure SF6 Puffer Circuit
                 Breaker
          6.9.2 Two-Pressure SF6 Circuit Breakers
          6.9.3 Bulk Oil Circuit Breakers
          6.9.4 Vacuum Circuit Breakers
          6.9.5 Air Magnetic Circuit Breakers
          6.9.6 Air Blast Circuit Breakers
          6.9.7 Minimum Oil Circuit Breakers
7.0 Failure Modes and Causes
PART B - DIAGNOSTICS
8.0 Diagnostics
ANNEXES
A Advanced Diagnostics (Informative)
B Diagnostic Tests (Informative)
     B.1 Mechanical Operation
     B.2 Insulation Power Factor
     B.3 Insulating Oil Testing
     B.4 Applied Voltage Test
     B.5 Electrical Resistance of Current Path
C Circuit Breaker Design (Informative)
     C1 Operating Mechanisms
     C2 SF8 Circuit Breakers
     C3 Bulk Oil Circuit Breakers
     C4 Vacuum Circuit Breakers
     C5 Air Magnetic Circuit Breakers
     C6 Air Blast Circuit Breakers
     C7 Minimum Oil Circuit Breakers
D Bibliography (Informative)
E Useful Imperial - Metric Conversion Factors
     (Informative)
FIGURES
Fig. 1 Suggested Investigation Flow-Chart
TABLES
Table 1 Suggested Checklist of Preparation Items
Table 2 Suggested Checklist of General Observations
Table 3 Electrical and Other Tests
Table 4 Diagnostics General Features of All Types of
           Circuit Breakers
Table 5 Diagnostics Special Features, Indoor Metal-
           clad Circuit Breakers
Table 6 Diagnostics Special Features, Air Magnetic
           Circuit Breakers
Table 7 Diagnostics Special Features, Vacuum Circuit
           Breakers
Table 8 Diagnostics Special Features, Bulk Oil
           Circuit Breakers
Table 9 Diagnostics Special Features, Minimum Oil
           Circuit Breakers
Table 10 Diagnostics Special Features, Two-Pressure
           SF6 Circuit Breakers
Table 11 Diagnsotics Special Features, Single- Pressure
           SF6 Circuit Breakers
Table 12 Diagnostics Special Features Air Blast
           Circuit Breakers
Table 13 Diagnostics Special Features Current
           Transformer Associated with Circuit Breakers