This document discusses common wire splices and joints, including the Western Union splice used for wires of the same size, the plain tap joint used to connect a branch wire to a main line, and the rat tail or pig tail splice that twists wires together to connect wires to conduits. It also mentions the cross joint for tapping two branch wires to a main wire and the Underwriter's knot in extension cords to relieve strain on small wires and binding screws.

1. Lesson 4
Common
Splices and
Joints

2. Western Union
Splice

3. Splice commonly
used in connecting
wires of the same
size.

4. Plain tap joint

5. An ordinary tap
used when
connecting the end
of a branch wire to
main line.

6. Rat tail or Pig Tail

7. This is used in making
connections between
wires and conduits.
The wires are simply
twisted around each
other.

8. Cross joint

9. When it is
necessary to tap
two branch of wires
to a main wire
make a cross joint.

10. Underwriter’s knot

11. KNOT that is made
in extension cords
and lamp cords. Its
purpose is to relieve
the strain on small

12. wires of the cord
and binding screws
of convenience
outlets, sockets and
male plugs.