Wires may be connected by joints, as well. If the joints are "bad," there will be poor electrical connections and the electricity may not get where it should be going.

Connecting wires securely is referred to as splicing or joining. To be considered well-done, a joint must be mechanically sound. That means there will be a good electrical connection. The joints will not fall apart easily even if it is not soldered or connected with electrical connectors.

Using your needle-nose pliers, cut six pieces of wire, each 100 mm long. Using a wire stripper or utility knife, strip 25 mm of insulation off one end of each wire (check with your teacher if you need help with the task).

Each pigtail splice uses two wires. Start the splice by crossing the wires as shown in the diagram.

1. Why must you be careful to not nick (cut into) the wire when removing insulation?

2. Why should the wire twists in a splice be tight and uniform?

3. Why should uneven ends of wires be trimmed once the splice is completed?

Method: Tap Splice

The tap splice is used where you want to join a second wire to a conductor.

Make three tap splices using two different lengths of the 14-guage solid wire. Submit one of your tap splices with your section 1 assignment.

Each tap uses two wires

• one piece of 14-guage solid wire, 100 mm long
• one piece of 14-guage solid wire, 150 mm long

Cut the two lengths of wire. Using a wire stripper or utility knife, strip off 65-70 mm from one end of he 150-mm-long wire. Using a utility knife, strip 15mm out of the middle of the 100-mm-long wire. Cut away from yourself. Take care not to nick the wire (this creates a weak spot that can break). Cross the long wire over the short wire at right angles, about 5 mm to 7 mm from the insulation on the 100-mm-long wire, as shown to the right.

Using pliers, grip both wires firmly. Use your fingers to twist or manipulate the stripped end of the long wire back and around the stripped part of the short wire (the 100-mm-long wire). Once you have made the first loop, use a second pair of needle-nose pliers to repeat the procedure to complete the wrapping. Keep the loops as tight and even as possible. Use the first pliers to grip each completed loop. Move the pliers along the completed splice.

Continue wrapping until all the stripped wire of the 150-mm length is wrapped (you should have about five complete wraps). Your wraps should not go over any insulation. Use your pliers to wrap in the end of the 150-mm wire.

Method: Western-Union Splice

A Western-Union splice or joint is used to securely fasten two stranded or two solid wires together. The best joint is made when the wires joined are the same size and type.

Make four Western-Union splices using the 18-guage stranded wire. Submit one of your Western-Union splices with your Section 1 assignment.

Each Western-Union splice uses two wires. Cut two 100-mm lengths of stranded wire. Using a wire stripper or utility knife, carefully strip 37 mm of insulation off one end of each wire. With your fingers, twist the bared strands of each wire tightly together (this makes a neater joint). Cross the wires over each other as shown. There should be about 12 mm between the crossover location and the insulation on each wire

Hold the crossed wires firmly with your free hand (or a pair of extra pliers). With your fingers (pliers should not be necessary with stranded wire), twist one free end back, down, and under the crossover location. Tightly wrap approximately two turns.

Next, wrap the other free end forward, down, and under the crossover location. Continue wrapping in this direction to the end of the wire. Complete the splice by wrapping the remainder of the first wire. Keep the wraps close together. You must have at least three turns on either side of the crossover. Make sure the stranded wire does not splay. Clip off the uneven ends of the wires.

Your Western-Union splice should look as follows.

4. Why must you be careful not to splay the stranded wire?

Method: Fixture Splice

The fixture splice is used when a solid wire and a stranded wire must be joined.

Make one fixture splice using solid wire and stranded wire. Submit your fixture splice with Section 1 assignment.

Each fixture splice uses two wires:

• one piece of 14-guage solid wire, 100 mm long
• one piece of 18-guage stranded wire, 100 mm long

Cut the lengths of wire. Using a wire stripper or utility knife, strip 37 mm of insulation from one end of the stranded wire. Strip about 25 mm of insulation from one end of the solid wire. Twist the end of the stripped stranded wire very firmly (this makes a neat splice; if the strands are not twisted firmly, you will get a very uneven wrap). Position the stranded wire at right angles about 4 mm from the insulation on the solid wire.

You will be wrapping the stranded wire around the solid wire.

Hold the insulated ends of the wire firmly in your free hand or in a pair of pliers. Use your fingers (the needle-nose pliers should not be necessary) to wrap the stranded wire around the solid wire. Make about five to seven tight wraps. Be careful not to splay the stranded wire.

When done wrapping, use the pliers to bend the end of the stripped solid wire over the back along itself. The turned-back end should be along the wrapped stranded wire. Clip off the uneven ends of the wires. Your splice should look like this.

5. Jeremy wants to join two wires of the same size and type in a straight line. Which type of wire splice should he use?