Broken copper wires can be temporarily repaired using crimped splices, terminal lugs with the tongue removed, or by soldering and potting the broken conductors. These repairs are applicable to copper wire. Damaged aluminum wire must not be repaired by temporary splicing.
These methods are intended for temporary emergency repairs only and should be replaced with permanent repairs as soon as practicable. Because some manufacturers prohibit wire splicing, always consult the applicable manufacturer's maintenance instructions before performing any repair.
Splicing with Solder and Potting Compound
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| Figure 1. Repairing broken wire by soldering and potting |
When neither a permanent splice nor a terminal lug is available, a broken wire can be repaired as follows [Figure 1]:
- 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 wire ends side by side and wrap one conductor 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.
- After the solder has cooled, 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 cure undisturbed for at least 4 hours. Full cure and electrical properties are achieved after 24 hours.
Quick Review: Emergency Splicing Repairs
When is an emergency wire splice acceptable in a powerplant electrical system?
An emergency wire splice is acceptable only when necessary to restore service temporarily and when permitted by the applicable manufacturer's maintenance instructions. A permanent repair or wire replacement should be completed at the earliest opportunity.
Why is wire replacement generally preferred over temporary splicing?
Replacing a damaged wire restores the electrical system to its original design and eliminates concerns about reduced mechanical strength, long-term reliability, and environmental resistance that may exist with temporary repairs.
What factors should be considered before performing a temporary wire repair?
Before carrying out a temporary repair, technicians should verify the wire material, evaluate the extent of the damage, ensure approved repair materials are available, and confirm that the repair method complies with the applicable maintenance documentation.
Why should temporary wire repairs be inspected after installation?
A post-repair inspection helps verify that the splice is mechanically secure, electrically sound, properly insulated, and adequately supported. It also confirms that the repaired section is protected from vibration, chafing, and other operating hazards.
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