Electrical Short Circuit/Arcing of Aged Aircraft Wiring

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

Figure 9. Circuit used for the wet dielectric tests.Electrical Arcing of Aged Aircraft Wire.Lectromechanical Design CompanyReport No. N191-RPT4AU99 August 12, 19998
DESCRIPTION OF ELECTRICAL ACTIVITYThree different categories of electrical activity were recorded during the arcingexperiments. They were scintillations, flashing and strong arcing. Each of these activitiesdeveloped a unique visual and oscillograph signature.ScintillationScintillations were the first electrical activity that was observed during the experiments.Visually, they began as pinpoints of light that flickered at the edge of the pre-damaged cracks inthe insulation (Figure 10). As time went on and a char track built up on the insulation, theflickers of light appeared at various places along the path between the pre-damaged cracks.During the more lively scintillations an electrical buzzing or crackling sounds could be heard. Noscintillations caused a circuit breaker to disrupt power.Figure 10. Scintillation at the edge of a pre-damaged crack.An oscillogram of scintillations (Figure 11) showed them to be high frequency eventswhich distorted the current and voltage waveforms. The frequency components appear to begreater than 1 megahertz. Quantitative measurements at these frequencies require the inductancesand capacitances of each of the components of the circuit (i.e. generator, circuit resistors,oscilloscope etc.) to be measured and analyzed which was not in the scope of this work. Energytransfer between wires cause voltage distortions (noise) and this process caused changes to theinsulation as a char path was built.Electrical Arcing of Aged Aircraft Wire.Lectromechanical Design CompanyReport No. N191-RPT4AU99 August 12, 19999
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: Figure 8. Apparatus used for metal
Page 17 and 18: The voltage and current waveforms w
Page 19 and 20: Figure 15. Example of a strong arci
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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