Electrician Tip to Control Fine Wires

Electricians Tip to control very fine wires (such as K class .010” stranded welding wire) while inserting into mechanical connector lugs

1. Strip insulation carefully to avoid nicking wires and pull off the jacket. A picture containing knife Description automatically generated
2. Wind 1-1/4 turns of PVC electrical tape around the outermost tip to contain the strands from splaying outward. Leave the end of the tape long and twisted for threading A pair of black gloves Description automatically generated with medium confidence
3. Insert the wire (tape first) into the mechanical lug with binding screw nose not intruding into the wire hole at all.

4. Tighten the screw down by hand.

5. Pull out the tape from the open back hole in the lug.

6. Fully torque the binding screw and hold the final rated torque for a full 5 seconds (per UL486A-B) to take up any creep in the compression process ( torque wrench may continue to turn clockwise as creep is taken up)

This method helps to :

1. Stop stray strand from being in the wrong place outside the lug which could cause an unintentional loss of pole to pole voltage spacing.
2. Stop stray strands from getting trapped in the binding screw thread which could create extra screw friction that is not helpful when tightening to torque.
3. Speeds up the insertion process especially on full sized wires since the insertion can be done more confidently knowing the strands will stay in place.

Some electricians use miniature wire ties as an alternative to tape.

As long as the method does not leave plastic remaining on the wire there is no issue with what containment tool is used.

Ferrules are also a great way to contain fine stranded wires. However UL486 requires that any deviations from Code Wire such as Flex wire or use of ferrules on the flex wire is tested and in the file for that connector and wire combination.

It is up to each installer to be aware of the strand control issues with fine stranded wire and take the needed precautions, and to invoke the necessary procedures to ensure professional workmanship.