crimping, interconnecting cables, harnesses, and wiring - NASA

More documents

Recommendations

Info

Figure 19-14. Western Union/Lineman Splice Page 84 of 114 NASA-STD-8739.4 with Change 6 19.9.1 Preparation. The conductors shall be pre-tinned (Requirement). There shall be at least 3 turns around each conductor and the wraps shall be tight with no gaps between adjacent turns (see Figure 19-15) (Requirement). The wraps shall not overlap and the ends of the wrap shall be trimmed flush prior to soldering to prevent protruding ends (Requirement). Conductors shall not overlap the insulation of the other wire (see Figure 19-16) (Requirement). Figure 19-15. Initial Wrap for Western Union/Lineman Splice Figure 19-16. Completed Wrap for Western Union/Lineman Splice 19.9.2 Soldering. The termination shall comply with all the requirements of NASA-STD- 8739.3 for a solder termination (Requirement). Solder shall wet all elements of the connection (Requirement). The solder shall fillet between connection elements over the complete periphery of the connection (see Figure 19-17) (Requirement). 19.10 Solder Ferrule Figure 19-17. Soldered Western Union/Lineman Splice The solder ferrule splice (see Figure 19-19) is fabricated using a crimp ferrule. This splice may only be fabricated as an end splice. Select the ferrule so that the ferrule fits over the inserted tinned wires, but not over the wire insulation. Maximum insulation clearance: the diameter of the ferrule. Minimum insulation clearance: the insulation does not interfere with the natural formation of the solder fillet. Maximum protrusion from the end of the ferrule: one wire diameter of the largest wire in the wire bundle. The minimum protrusion from the end of the ferrule: even with the end of the ferrule and visible after soldering. The solder shall fill the ferrule and be visible at both ends (Requirement).
Page 85 of 114 NASA-STD-8739.4 with Change 6 19.10.1 Preparation. Clean the ferrule. The conductors shall be pre-tinned, parallel to, and in contact with each other as indicated in figure 19-18 (Requirement). The conductors to be spliced shall not be twisted together (Requirement). The ferrule to be used shall be pre-tinned using a solder pot or solder iron (Requirement). Insert the wires from one end and adjust for insulation clearance and wire protrusion. Secure the wires with a spot tie or similar means to prevent movement during soldering. Trim protruding conductors even with each other with a maximum protrusion of one wire diameter of the largest wire in the wire bundle. Figure 19-18. Solder Ferrule 19.10.2 Soldering. Apply heat at the end of the ferrule away from the wire insulation. Solder shall be applied at the insulation end of the ferrule (Requirement). Fill the ferrule completely with solder. 19.11 Crimped Splices Maximum insulation clearance is the diameter of the ferrule Maximum protrusion of one wire diameter of largest wire in bundle Figure 19-19. Solder Ferrule Crimping wires into contacts is a method for splicing wires together without soldering. The tooling verification process and the completed termination shall comply with all the requirements of this document for a crimp termination except as specified herein for jiffy junction devices (Requirement). The contact/wires size and crimp tool setting combination shall be verified using the same requirements as for any machined contact (see 12.3.4) (Requirement). Create 3 test specimens and pull each wire in the specimen. The wire pulled shall meet the tensile requirement for a single wire of the same gage being tested in its “properly sized” contact (Requirement).
Page 1 and 2:
NASA TECHNICAL STANDARD National Ae
Page 3 and 4:
Status Document Revision DOCUMENT H
Page 5 and 6:
This page intentionally left blank.
Page 7 and 8:
Page 7 of 114 NASA-STD-8739.4 with
Page 9 and 10:
TABLE OF CONTENTS Page 9 of 114 NAS
Page 11 and 12:
Page 13 and 14:
Page 15 and 16:
LIST OF TABLES Page 15 of 114 NASA-
Page 17 and 18:
2. APPLICABLE DOCUMENTS 2.1 Applica
Page 19 and 20:
PVDF Polyvinylidene Fluoride RF Rad
Page 21 and 22:
Page 23 and 24:
4. GENERAL 4.1 General Page 23 of 1
Page 25 and 26:
5. TRAINING AND CERTIFICATION PROGR
Page 27 and 28:
Page 29 and 30:
6. FACILITIES, EQUIPMENT, MATERIALS
Page 31 and 32:
Page 33 and 34: Page 33 of 114 NASA-STD-8739.4 with
Page 37 and 38: 8. INTERCONNECTING CABLE/HARNESS FI
Page 41 and 42: Figure 9-1. Starting Stitch Figure
Page 45 and 46: Figure 9-8. Starting Lock Figure 9-
Page 47 and 48: 9.7 Metal Braid Shielding Figure 9-
Page 57 and 58: Figure 11-4. Group Grounding of Sta
Page 59 and 60: 11.8 Floating Shield Terminations F
Page 63 and 64: c. Records of examination shall be
Page 83: Page 83 of 114 NASA-STD-8739.4 with
Page 95 and 96: . Shield Terminations: (1) Shield t
Page 97 and 98: (4) Mating surfaces and coupling me
Page 99 and 100: (10) Tarnished, corroded, or contam
Page 101 and 102: Page 101 of 114 NASA-STD-8739.4 wit
Page 103 and 104: WIRE PREPARATION: MECHANICAL STRIPP
Page 107 and 108: FIGURE A-25 FIGURE A-26 CRIMPS: INS
Page 109 and 110: FIGURE A-29A CRIMPS: UNACCEPTABLE P
show all

crimping, interconnecting cables, harnesses, and wiring - NASA

You also want an ePaper? Increase the reach of your titles

Delete template?

Save as template?