Electrical Short Circuit/Arcing of Aged Aircraft Wiring

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

Table 4. Summary of Metal Shavings Abrasion Test: 90° (Right Angle)Wire Spec Test # ShavingMaterialShaving Crosssection (Mils) Duration QualitativeDescription# CircuitBreakersTripped# of Wires thatFailed WetDielectric TestInsulation DamageW 42A/8/1-20 Test 16A Steel 41 X 26 19.25 hours No Flash 0 1 of 7 Moderate damage to PolyXFlexing broke 1 wireW 42A/8/1-20 Test 16B Al 7075 42 X 30 19.25 hours No Flash 0 2 of 7 Moderate damage to TopcoatFlexing broke/cracked 2 wiresTable 5. Summary of Metal Shavings Abrasion Test: LongitudinalWire Spec Test # ShavingMaterialShaving Crosssection (Mils) Duration QualitativeDescription# CircuitBreakersTripped# of Wires thatFailed WetDielectric TestInsulation DamageW 42/1/1-20 Test 17 Steel ~40 X 25 1+ hours Small Flash 0 2 of 8 Cuts in Poly X to the conductorW 42/1/1-20 Test 19 Steel 49 X 18 4 hours No Flash 0 2 of 8 Cuts in Poly X to the conductorW 42/1/1-20 Test 18 Al 7075 48 X 26 ~15 minute No Flash 0 0 of 8 Abrasion of TopcoatW 42/1/1-20 Test 20 Al 7075 120 X 6 4 hours No Flash 0 0 of 8 Abrasion of TopcoatElectrical Arcing of Aged Aircraft Wire.Lectromechanical Design CompanyReport No. N191-RPT4AU99 August 12, 199918
APPENDIX A: Description of Individual Test ResultsWet Arc Tracking TestsPreliminary Tests A & BWet Arc TrackingBundle: Seven wires (6 over 1) of BMS 42/1/1-20 specification, 15 inches in length.Electrolyte: 1% saline solution @ 100mg/minuteCircuit Resistance: 1 OhmGenerator: 3 phase, 400Hz, 120 line to neutral (208 line to line), 10 kVA.Length of tests: 5 minutes (Test A) and ½ minute (Test B)ObservationPreliminaryTest APreliminaryTest BVisible scintillation Yes YesFlash Yes YesStrong Arcing No ApproachingCircuit Breakers Tripped No NoDamage Length 1/2" 1/4"Number of Wires Failing WetDielectric TestBoth tests gave similar results although preliminary test A was run for 5 minutes andpreliminary test B was run for only ½ of a minute. Both began scintillations almost immediatelyand soon developed flashing type events.In test A the sample was very active for the first minute or so and then had periods ofdormancy interrupted by short spurts of activity. Examination of the bundle shows damage andchar for about ½ an inch around the pre-damaged cuts. Also, about 3/8 of the conductors of thetop two wires had been eroded away (Figure 18).The bundle in test B experienced a period of intense activity within the first 30 secondsapproaching strong arcing with 20+ cycles of continuous arcing (Figure 19). This periodincluded current peaks of 75 Amperes and over 350 joules of electrical energy was dissipated inthe event. The sample was then removed and examined. There was about a 1/4 inch of damageand char build up around the cut in the insulation, but both conductors were still intact.No circuit breaker tripped in either test.__Electrical Arcing of Aged Aircraft Wire.Lectromechanical Design CompanyReport No. N191-RPT4AU99 August 12, 199919
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 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: Table 3. Summary of Metal Shavings
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

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