rel="nofollow" href="#ulink_952766eb-98b1-51ed-a844-cd4f34b248d1">Figure 1.1. Treeing phenomena in nonself-restoring insulation, leading to ulti...Figure 1.2. The various stages of pressure buildup and its release for an arc ...Figure 1.3. Pressure versus distance from the center of the arc, based on Lee’...Figure 1.4. Peak sound pressure in dBA, at a distance of 1.8 m from a variety ...Figure 1.5. Average arcing current versus the peak sound pressure dBA. Source:...Figure 1.6. Fibrillating current (ma) rms, versus body weight. Source: Referen...Figure 1.7. Ventricular fibrillation curves, current versus time. Source: Refer...Figure 1.8. Shock hazard categories according to IEC. Figure 1.9. Hazard boundaries around an arcing source, adapted from NFPA 70E. Figure 1.10. To illustrate the arcing time for low voltage circuit breakers, a...Figure 1.11. An outfit for PPE HRC4.Figure 1.12. A specimen arc flash label.2 Chapter 2Figure 2.1. Logo for the U.S. NIOSH PtD initiative.Figure 2.2. Key elements of safety by design.Figure 2.3. Statistics of electrical nonfatal injuries, industrywise, from 19...Figure 2.4. Fatalities in the construction industry, 1992–2002. 1: Tot...Figure 2.5. Percentage survival rate with respect to percentage body burns and...Figure 2.6. Risk and safety integrated concepts.Figure 2.7. Flow chart-risk assessment procedure.Figure 2.8. Elements of risk.Figure 2.9. Risk management process.
3 Chapter 3Figure 3.1. Electrode configurations.Figure 3.2. Iarc versus Voc for 208–1000 V, Comparison of IEEE 2002 versus 2018.Figure 3.3. Iarc versus Voc for 1–15 kV, Comparison of IEEE 2002 versus 2018.Figure 3.4. Flow chart for the calculation of arc flash hazard.
4 Chapter 4Figure 4.1. Methods of system grounding. Figure 4.2. Arc fault in a 3/16″ gap, 480-V system.Figure 4.3. Overvoltage versus ratio of resistor kW/charging kVA.Figure 4.4. (a and b) The stray capacitance currents and voltages in a low vol...Figure 4.5. (a) Selective ground fault protection in a high resistance grounde...Figure 4.6. (a) Corner grounded delta grounded system; (b) mid-point grounded ...Figure 4.7. (a) Zigzag grounding transformer showing winding connections, curr...Figure 4.8. Methods of low resistance or high resistance grounding of neutrals...Figure 4.9. A solidly grounded distribution system for selective ground fault ...Figure 4.10. A three-step ground fault coordination of the distribution system...Figure 4.11. Phase fault coordination of the system of Figure 4.9.Figure 4.12. Ground fault protection coordination with superimposed phase faul...Figure 4.13. Distribution system in Figure 4.9, modified for improved selective...Figure 4.14. Ground fault coordination, with low ground fault pickup settings ...Figure 4.15. A medium voltage low resistance grounded distribution system for ...Figure 4.16. Selective ground fault coordination of system in Figure 4.15, ext...Figure 4.17. Ground fault coordination in a large interconnected 13.8-kV syste...Figure 4.18. Selective ground fault coordination for the 13.8-kV distribution ...Figure 4.19. Derivation of a zero sequence polarizing voltage for directional ...
5 Chapter 5Figure 5.1. Decaying AC and DC components of the short-circuit current and the...Figure 5.2. Equivalent machine model for short-circuit calculations.Figure 5.3. Multiplying factors for E/X or E/Z amperes, three-phase faults, fo...Figure 5.4. (a) Typical computer-based calculation results, momentary (first cy...Figure 5.5. A low voltage distribution system for calculations of short-circui...Figure 5.6. Equivalent network for a fault at bus 3 (Figure 5.5 and Example 5....Figure 5.7. Equivalent network for a fault at bus 2 (see Figure 5.5 and Exampl...Figure 5.8. A multivoltage distribution system for hand calculations of short-...Figure 5.9. Equivalent network for a fault at 13.8 kV bus 2 (see Example 5.2).Figure 5.10. (a) Line-to-ground fault in a three-phase system, (b) line-to-gro...Figure 5.11. (a) Double line-to-ground fault in a three-phase system, (b) doub...Figure 5.12. (a) Two-phase fault in a three-phase system, (b) Two-phase fault-...Figure 5.13. Equivalent zero sequence circuit for a fault on bus 2 (Example 5....Figure 5.14. (a) Equivalent zero sequence circuit of a transformer with primar...Figure 5.15. Equivalent admittance diagram of the system in Figure 5.5.
6 Chapter 6Figure 6.1. Time constant of exponential DC decaying component of the short-ci...Figure 6.2. (a) Short-circuit current profile utility source only, no generator...Figure 6.3. Equivalent transformer circuits of a synchronous generator during ...Figure 6.4. Decaying AC component of the short-circuit current showing subtran...Figure 6.5. Calculated fault decrement curve of generator (DC component not sh...Figure 6.6. Calculated short-circuit currents for terminal fault of a 900 hp, ...Figure 6.7. A 13.8 kV bus with multiple sources of short-circuit currents.Figure 6.8. (a–c) Accumulation of incident energy profiles (see text).Figure 6.9. Calculation of short-circuit current decay profiles at 13.8 kV bus ...Figure 6.10. Crowbar arrangement.
7 Chapter 7Figure 7.1. Functionality of a MMPR (multifunction microprocessor-based relay)...Figure 7.2. An electromechanical overcurrent relay. Source: IEEE standard 141-...Figure 7.3. Time–current inverse characteristics of various overcurrent relay ...Figure 7.4. Instantaneous overcurrent function logic in an MMPR.Figure 7.5. Time–overcurrent characteristics of various overcurrent relay type...Figure 7.6. A low voltage system for illustration of selection of transformer ...Figure 7.7. Time–current coordination plot related to Figure 7.6, Example 7.2.Figure 7.8. A bimetallic thermal trip device. (a) Normal state and (b) tripped...Figure 7.9. A magnetic instantaneous trip device. (a) Normal state and (b) tri...Figure 7.10. (a) Current limitation, operation of a current limiting MCCB; (b)...Figure 7.11. Operation of a MCCB, not specifically designated as current limiti...Figure 7.12. Let-through characteristics of a current limiting MCCB.Figure 7.13. Time–current characteristics of a modern low voltage electronic t...Figure 7.14. Low arc flash circuit breaker design. Source: Arc-Flash Protection...Figure 7.15. Short-time bands of a low voltage trip programmer, to show coordi...Figure 7.16. A low voltage double-ended substation for calculations of arc flas...Figure 7.17. Let-through characteristics of a current-limiting fuse.Figure 7.18. Example of an installation where the motor contribution exceeds N...Figure 7.19. Current interruption by a current-limiting fuse.Figure 7.20. Arc voltage generated by a current limiting fuse during interrupt...Figure 7.21. Relation of X/R to rms and peak multiplying factors. Source: Base...Figure 7.22. Low voltage distribution system with integrally fused main second...Figure 7.23. Coordination in the distribution system of Figure 7.22. Current l...Figure 7.24. Coordination in the distribution system of Figure 7.22, modified b...Figure 7.25. Variations in the time–current characteristics of 150-A class E f...Figure 7.26. Thermal withstand curve of a 2.4-kV, 400-hp, SF = 1.15 motor.Figure 7.27. (a) and (b) Protection of thermal withstand curve of the motor in...Figure 7.28. Premature trip of 400-hp motor with overcurrent setting in Figure...Figure 7.29. A two-step overcurrent relay characteristics and motor starting c...Figure 7.30. Application of a zero-speed switch and an overcurrent element for...Figure 7.31. A practical time–current coordination of a 2.3-kV, 1000-hp motor ...Figure 7.32. A parallel
