4.1.7 JointsA joint in a solid conductor or in one of the individual wires of a stranded conductor shall neither increasethe diameter nor materially decrease the strength of the conductor or the individual wire. No more thanone of the wires in a stranded conductor of 19 wires or less, or more than one of the wires in any givenlayer in a stranded conductor of more than 19 wires, shall be joined in any 0.3 m (1 ft) of conductor.In a rope-lay-stranded conductor, which consists of a central core surrounded by one or more layers ofstranded members (primary groups), each member shall be considered equivalent to a solid wire, and assuch, may be spliced as a unit. These joints shall not be any closer together than two lay lengths.