Electrical Short Circuit/Arcing of Aged Aircraft Wiring

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$Atago Co., Ltd. Salinity Refractometer, Model S-10 Instruction Manual$

Figure 13. Oscillogram of voltage and current during a flashing event.Figure 14. The electrical power dissipated during a flash event.Electrical Arcing of Aged Aircraft Wire.Lectromechanical Design CompanyReport No. N191-RPT4AU99 August 12, 199912
Figure 15. Example of a strong arcing event.Strong ArcingStrong Arcing events were characterized by an active bright flash or glow that continuedfor a up to a second or more (Figure 15) with an intense electrical hum or crackling. The arc cancause much collateral damage to the insulation of adjacent wires, some of which becameinvolved in the event. Strong arcing was often terminated with tripping of the circuit breaker.The difference between the oscillogram of a flash and a strong arcing event is that thesame voltage arc waveform is repeated continuously in the arc at each half cycle for the durationof the short circuit. The phase to phase voltage at the beginning of an arc is shown in Figure 16 .The current in this arc started out in the range of 65 amperes (peak). After the other wires(including the phase C wire) became involved in the arc the current increased to peaks of 120amperes. Power peaks were found of up to 15 kW (Figure 17) and a total electrical energydissipated of about 5 kilojoules (kJ) .The magnitudes of the power peaks in the strong arcing event shown in Figure 17 areabout a factor of 2 higher than those found in the flashing event previously discussed becausemore wires were involved. Also different is the arc waveform is repeating continuously forhundreds of cycles in a strong arcing event, as compared to one to ten or twenty cycles for aflashing event. This increases the time in which energy is dissipated in a strong arcing event.Electrical Arcing of Aged Aircraft Wire.Lectromechanical Design CompanyReport No. N191-RPT4AU99 August 12, 199913
Page 3 and 4: Electrical Arcing of Aged Aircraft
Page 5 and 6: were placed between wires in small
Page 7 and 8: BackgroundArc tracking of aircraft
Page 9 and 10: EXPERIMENTAL PROCEDURESWet Arc Trac
Page 11 and 12: Figure 5. Circuit used in the metal
Page 13 and 14: Figure 8. Apparatus used for metal
Page 15 and 16: DESCRIPTION OF ELECTRICAL ACTIVITYT
Page 17: The voltage and current waveforms w
Page 21 and 22: RESULTSTable 1 lists the Test run g
Page 23 and 24: Table 3. Summary of Metal Shavings
Page 25 and 26: APPENDIX A: Description of Individu
Page 27 and 28: Test 1 & 2Wet Arc TrackingBundle: S
Page 29 and 30: Figure 22. Test 1: Oscillogram show
Page 31 and 32: Test 3Wet Arc TrackingBundle: Seven
Page 33 and 34: Figure 26. Test 3: Sample bundle af
Page 35 and 36: Figure 27. Test 4: Strong arcing on
Page 37 and 38: Test 6 & 7Wet Arc TrackingBundle: S
Page 39 and 40: Figure 32. Test 6: Sample bundle af
Page 41 and 42: Test 9:Bundle: Seven wires (6 over
Page 49 and 50: Figure 37. Test 14: Electrical powe
Page 51 and 52: Metal Shavings AbrasionTest 16 A &
Page 53 and 54: Test 17 & 192 Bundles: four wires e
Page 55 and 56: Figure 42. Test 17: Damage to wire
Page 57 and 58: Figure 44. Test 20: Damage done in
Page 59 and 60: Table 7. Description of alternate a

Electrical Short Circuit/Arcing of Aged Aircraft Wiring

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