Broken wires can be repaired by means of crimped splices, by using terminal lugs from which the tongue has been cut off, or by soldering together and potting broken strands. These repairs are applicable to copper wire. Damaged aluminum wire must not be temporarily spliced. These repairs are for temporary emergency use only and should be replaced as soon as possible with permanent repairs. Since some manufacturers prohibit splicing, the applicable manufacturer’s instructions should always be consulted.
Splicing with Solder and Potting Compound
When neither a permanent splice nor a terminal lug is available, a broken wire can be repaired as follows [Figure 4-108]:
- Install a piece of plastic sleeving about 3 inches long and of the proper diameter to fit loosely over the insulation on one piece of the broken wire.
- Strip approximately 1½ inches from each broken end of the wire.
- Lay the stripped ends side by side and twist one wire around the other with approximately four turns.
- Twist the free end of the second wire around the first wire with approximately four turns. Solder the wire turns together using 60⁄40 tin-lead resin-core solder.
- When solder is cool, draw the sleeve over the soldered wires and tie at one end. If potting compound is available, fill the sleeve with potting material and tie securely.
- Allow the potting compound to set without touching for 4 hours. Full cure and electrical characteristics are achieved in 24 hours.