Wire joints – Types

 

Wire joints – Types

Definition of joint: A joint in an electrical conductor means connecting/tying or interlaying together of two or more conductors such that the union/junction becomes secured both electrically and mechanically.

Types of joints:

Pig-tail/Rat-tail/Twisted joint:		Used in a junction box and for connecting branch circuits. joint is suitable for pieces where there is no mechanical stress on the conductors
Married joint:		The married joint is an electrical joint used for joining multi-strand cables. A married joint is used where electrical conductivity is required, along with compactness.
Tee joint		This joint could be used in overhead distribution lines where the electrical energy is to be tapped for service connections.
Britannia straight joint:		This joint is used in overhead lines where considerable tensile strength is required. It is also used both for inside and outside wiring where single conductors of diameter 4 mm or more are used.
Britannia tee joint:		This joint is used for overhead lines for tapping the electrical energy perpendicular to the service lines.
Western union join		This joint is used in overhead lines for extending the length of wire where the joint is subjected to considerable tensile stress.
Scarfed joint		This joint is used in large single conductors where good appearance and compactness required and there is no strain on the wire.
Plain tap joint:		This joint is the most frequently used, and is quickly made.
Aerial tap joint :		This is used as a temporary tap usually done in construction sites. This joint is suitable for low current circuits only.
Knotted tap joint :		A knotted tap joint is designed to take considerable tensile stress.
Duplex cross-tap joint:		This joint is used where two wires are to be tapped at the same time.
Double-cross tap joint		It is used where two tap conductors need to extend away from the branch conductor in the opposite direction.