|
| |
TM 9-4120-389-14
4-36. ELECTRICAL HIRING REPAIR GENERAL.
Preferred repair method consists of replacing wires, terminals, connectors, etc., rather than splicing wires,
bending ends to form terminals, and other make-shift procedures; although the latter may be appropriate for
emergency field repairs. Determine the proper size and length of wire, or the terminal, or connector to be used
for replacement by referring to table 4-3, "Wire List", and to the wiring diagram.
a.
Soldering connections. Wire connections must be made mechanically sound before they are
soldered; solder alone does not provide sufficient strength to prevent breakage. Joining surfaces of connections
to be soldered must be clean and bright. If a separate flux is used, it should conform to Specification MIL-F-
14256, rosin base flux, and should be brushed into the joint before soldering. If a slux-core solder is used, it
should always be rosin-core electrical solder. If an uncored solder is used, it should be a lead-tin solder, item 2,
Appendix E, conforming to Specification QQ-S-571. Wires should always be heated to the point at which the
solder will melt completely and flow into all parts of the joint. Excessive build-up of solder "gobs" on the joint
should be avoided or removed.
b.
Insulating joints. The preferred method of insulating electrical joints is by the use of heat-shrink
tubing. To apply, cut a piece of heat-shrink tubing of suitable diameter to a one-inch for covering joints at
terminals or connectors, or to a length about 1/2 inch (1.3 cm) longer than the joint to be insulated, and slide
the tubing over the wire before making the joint. After the joint is made, slide the tubing so that it covers the
joint, and shrink in place with heatgun (Item 5, Appendix B).
c.
Splicing wires. To repair broken or cut wires that are otherwise sound, the mating ends can be
stripped and spliced. A commercial butt splice can be crimped onto the end to join them, or a "Western Union"
wire splice can be made. The latter is made by stripping 1/4 - 1/2 inch (.06 - 1.3 cm) of insulation from the wire
ends, holding the ends parallel and facing opposite directions, then twisting each end around the other wire at
least three turns. Solder and apply insulation as described above.
d.
Crimping terminals. To install a terminal on the end of a wire, strip 1/4 - 1/2 inch (0.6 - 1.3 cm) of
insulation from the end of the wire, apply a one-inch piece of heat-shrink tubing (if the terminals are of the
uninsulated type), and insert wire end into the shank of the terminal. Crimp the shank, and install heat-shrink
tubing, if necessary.
4-114
|
