J. C. Das - Arc Flash Hazard Analysis and Mitigation

11 Chapter 11Figure 11.1. Faults in the secondary zone shown in solid block cleared by prim...Figure 11.2. (a) A radial system of distribution, (b) primary selective system...Figure 11.3. ANSI through fault withstand curve, category I transformers, liqu...Figure 11.4. ANSI through fault withstand curve, category II transformers: (a)...Figure 11.5. ANSI through fault withstand curve, category III transformers: (a...Figure 11.6. ANSI through fault withstand curve, category IV transformers, liq...Figure 11.7. ANSI through fault withstand curve, category I, dry-type transfor...Figure 11.8. ANSI through fault withstand curve, category II, dry type transfo...Figure 11.9. Analytical construction of a through fault curve.Figure 11.10. Variations in the total clearing time–current characteristics of...Figure 11.11. Line and winding currents in transformers for various secondary ...Figure 11.12. Through fault withstand curve protection of a 2500-kVA, Z = 5.75...Figure 11.13. Through fault withstand curve protection of a 2500-kVA, Z = 5.75...Figure 11.14. Less flammable liquid-immersed transformers compliance to NEC sec...Figure 11.15. Less flammable liquid immersed transformers compliance to NEC sec...Figure 11.16. A low voltage and medium voltage distribution system for protect...Figure 11.17. Time–current coordination plot for 480-V, 2000-kVA transformer p...Figure 11.18. Time–current coordination plot for 2.4-kV, 7500-kVA transformer ...Figure 11.19. Modified distribution system of Figure 11.16, for arc flash reduct...Figure 11.20. Time–current coordination plot for 480-V, 2000-kVA transformer p...Figure 11.21. Time–current coordination plot for 2.4-kV, 7500-kVA transformer ...Figure 11.22. Time–current coordination plot for 480-V, 2000 kVA transformer p...Figure 11.23. Time–current coordination plot for 2.4-kV, 7500-kVA transformer ...Figure 11.24. A microprocessor based overcurrent relay connected through CTs o...

12 Chapter 12Figure 12.1. Excitation characteristics of C-type current transformers, showin...Figure 12.2. Excitation characteristics of T-type current transformers.Figure 12.3. Construction of various CT types: (a) window-type CT, (b) a fully...Figure 12.4. Excitation characteristics of a 100/5 core balance CT. V kis the ...Figure 12.5. Phase diagram of a class C current transformer.Figure 12.6. Illustrates the composite error according to IEC standards.Figure 12.7. Location of window type CTs in metal-clad draw-out switchgear. Tw...Figure 12.8. (a) Subtractive polarity and (b) additive polarity, shown by dark...Figure 12.9. (a) Residual connection of a GR fault relay through auxiliary wou...Figure 12.10. Connections of a product-type electromechanical ground fault rel...Figure 12.11. (a) Connection of a single 600/5 ratio CT, secondary voltage 162...Figure 12.12. Oscillogram showing progressive saturation of a CT.Figure 12.13. Hysteresis loop on magnetization of a magnetic material.Figure 12.14. Output of a 100/5 ratio C50 CT for a 40-kA fault current, severe...Figure 12.15. Improved response for 40 kA fault current, 200/5 ratio, C100 CT ...Figure 12.16. Adaptive overcurrent element block circuit diagram showing bipol...

13 Chapter 13Figure 13.1. Time–current characteristics of four low voltage devices for anal...Figure 13.2. Calculated incident energy release versus three-phase bolted shor...Figure 13.3. A typical indicator frame used in arc-resistance testing.Figure 13.4. Pressure buildup after an arc flash event, with and without ventin...Figure 13.5. Flap plates on an arc-resistant equipment, normally closed.Figure 13.6. Hinged arc panels with inner shield.Figure 13.7. Pressure relief plate after an arc flash event.Figure 13.8. Typical arc-resistant medium voltage enclosure with arc chimneys....Figure 13.9. Typical arc-resistant medium voltage enclosure with plenum. Sourc ...Figure 13.10. Inappropriate design of external arc venting system.

14 Chapter 14Figure 14.1. Statistical data of arc flash hazard with respect to voltage level...Figure 14.2. Incident energy release verses percentage of buses, all voltages....Figure 14.3. Zone interlocking between feeder and main secondary circuit break...Figure 14.4. Zone interlocking between feeder and main secondary circuit break...Figure 14.5. A low voltage distribution system for study of zone interlocking.Figure 14.6. Time–current coordination of devices in Figure 14.5, with and wit...Figure 14.7. A low voltage distribution system, with considerable rotating mot...Figure 14.8. Time–current coordination of devices in Figure 14.7, showing moto...Figure 14.9. Zone interlocking in medium voltage system with two sources of po...Figure 14.10. Instantaneous values of short-circuit wave forms from three sour...Figure 14.11. (a) Location of a fault through sensing the fault current direct...Figure 14.12. A block circuit diagram of microprocessor-based low voltage swit...Figure 14.13. A low voltage distribution system with provision of 1000-A class...Figure 14.14. Time–current coordination of the devices in Figure 14.13, withou...Figure 14.15. Time–current coordination of the devices in Figure 14.13, with 1...Figure 14.16. Picture of a voltage indicator mounted on a low voltage MCC door...Figure 14.17. Portable remote racking system for low voltage MCC buckets.Figure 14.18. Another version of a portable remote racking system for low volt...Figure 14.19. Picture of a low voltage MCC bucket, showing safety shutter posi...Figure 14.20. A control circuit diagram for connections of maintenance mode sw...Figure 14.21. Arc fault resistance infrared sight glass.Figure 14.22. Field of view of an infrared window equal to six times the cabin...Figure 14.23. A combination of viewing window and infrared window.Figure 14.24. Assembly of a TCL (also called FCL).Figure 14.25. Schematic diagram of a TCL.Figure 14.26. The timing diagram of a TCL with magnitude sensing.Figure 14.27. Arresting the system voltage dip with TCL.Figure 14.28. (a) TCL used in a reactor bypass scheme; (b) time–current profil...Figure 14.29. Normalized NQN and PDI (see text).Figure 14.30. PD measurement data of a generator over the course of years.Figure 14.31. CSA (current signal analysis) of a rotating machine showing brea...Figure 14.32. Model of a leaky dielectric and loss angle (see text).

15 Chapter 15Figure 15.1. Short-circuit profile of various DC sources: (a) rectifier with a...Figure 15.2. Standard approximation of short-circuit function. Source : Referen...Figure 15.3. A DC distribution system for calculation of short-circuit current...Figure 15.4. Equivalent circuit of short circuit of a battery through external...Figure 15.5. Time to peak t pkand rise time constant τ 1Bfor the short-circuit...Figure 15.6. Layout of a battery system for calculation of short-circuit curre...Figure 15.7. Calculated short-circuit time–current profiles: (a) battery, (b) ...Figure 15.8. Factors κ 1Mand κ 2Mfor determining the time to peak t pMand the ...Figure 15.9. Short-circuit current profile of a rectifier.Figure 15.10. Equivalent circuit for the short-circuit current calculation of ...Figure 15.11. Total short-circuit current profile of four partial short-circui...Figure 15.12. (a) Minimum arc voltage for vertical arcs; (b) minimum arc volta...Figure 15.13. A simplified model of arcing in a DC system.Figure 15.14. Arcing current profile superimposed on the short-circuit current...Figure 15.15. Time–current characteristics of a class L, 1000-A fuse.Figure 15.16. Calculated short-circuit and arcing current profiles (see Exampl...Figure 15.17. Short-circuit current of a converter with grid (gate) control. S ...

16 Chapter 16Figure 16.1. Power station substation automation (SA) functional diagram.Figure 16.2. IEC 61850 communication profiles.Figure 16.3. Hierarchy of IEC 61850 data model.Figure 16.4. Circuit breaker Model-XCBR information tree.Figure 16.5. Anatomy of IEC 61850 object nomenclature.Figure 16.6. GOOSE messaging.Figure 16.7. (a) Fiber optic multimode cable cross-section and light transmi...Figure 16.8. (a) Redundant star architecture using redundant ports on IEDs; ...Figure 16.9. A schematic picture of substation layouts and connections in a ...