Lecture on Wire Splicing and

Termination

Prepared by Amit Kumer Podder

Khulna University of Engineering & Technology (KUET)

Wire Splicing A wire spice is when two pieces of electrical wire are taken and join

them together with a crimp, butt-splice, or heat shrink to make a

complete electrical connection.

Importance of Wire Splicing

The Splicing or jointing is required since the wires are manufactured in 100

metres lengths and the total length of wire used for house wiring may be

more than 100 metres.

The jointing conductors and wires should always be carried out at outlets

i.e. in switches,ceiling roses using the looping in system or in junction

boxes.

Splicing should never be done in conduit runs but sometimes necessary

when repairing old works.

Various Kinds of Splicing Techniques

Western Union Splice or Twist Splice

Married Joint

Single Branch Splice or A Tap Joint

Double Branch Splice

Flexible Cord Splicing

Pigtail Joint

Pigtail Joint of a Solid Conductor and A Flexible Wire

Western Union Splice or Twist Splice

It can be completed in four steps--

1. Removing Insulation

2. Mechanically jointing the conductors

3. Soldering the joint

4. Tapping the soldered joint

Removing Insulation

Mechanically jointing the conductors

Soldering the joint

Tapping the soldered joint

Married joint

For a wire having one strand only ,the joint made is called

twisted joint, but for wires having a number of strands ,the

joint is called as married joint.

Spreading of Strands

Married joint

Intersecting of Strands of two wires

Twisting of Strands Finishing Joints

Single Branch Splice or Tap joint

Sometimes It is necessary to tap the electrical energy from a running line .In that case one free end of the wire is available and thus the twist joint is not possible which necessarily requires two free ends. So in such circumstances a T joint is necessarily made.

Removing the insulation

Single Branch Splice or Tap joint

Neck turn for making T-joint

Finishing Joints

Double Branch Splice

The double branch splice is used when the electrical energy is

required to be sent in two directions at right angles to each

other.

Tap Joint for stranded wires

For Stranded wires the single branch or the tap joint is made

below---

Flexible Cord Splicing

Sometimes it is necessary to provide a joint in a twin core cord.

In such cases the two joints of the cores must be staggered as

presented below--

Pigtail Joint

The Pigtail joint is the most important joint, since it is often

required of termination of the wires in switches, holders etc as

presented below–

Pigtail Joint of a Solid Conductor and a

flexible wire

Such a joint is made in a manner similar to that of an ordinary

pigtail joint ,except that after wrapping the stranded wire round

the solid conductor for a length of 2.5 cm as presented below–

Termination of the Wire

While making termination ,the insulation of the wire is brought

near the screw ,it is wrong method to keep it away as presented

below as such a termination causes a short circuit–