TM9-4120-400-14
4-20. ELECTRICAL WIRING REPAIR - GENERAL.
Repair
This task covers:
INITIAL SETUP
Materials/Parts
TOOIS
Wire
Refrigeration Unit Service Tool Kit
Insulation Sleeving
Solder
Crimping Tool Kit
Heat Gun
REPAIR
1. 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. Flux should be brushed onto the joint before soldering. 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.
2. 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 length of 1 inch (2.5 cm) 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. 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 moderate heat.
3. 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 ends to joint them, or a `*Western Union" wire splice can be
made. The latter is made by stripping 1/4 - 1/2 inch (0.6 -1.3 cm) of insulation from the wire ends, and
sliding on a piece of insulation tubing as described above. Hold the ends parallel and facing opposite
directions, then twist each end around the other wire at least three turns. Solder and apply insulation as
described above.
4. 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 (2.5 cm) piece of heat-shrink tubing (if the terminals are of the uninsulated type).
Insert wire-end into the shank of the terminal. Crimp the shank and install heat-shrink tubing, if necessary.
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