Original Version

Rule 59.3-E4

59.3-E4)    In Conduits: Common neutral conductors may be installed in the same conduits with related phase conductors, provided that the insulation of the neutral conductor is not less than that required of the phase wires and, further, that it is treated as a phase wire for the entire run between terminals.  Where the conduit installation is an effectively grounded metal riser pipe, the reference to insulation of the common neutral need not apply, provided the neutral conductor is connected to both ends of the riser pipe and effectively, grounded.

Strikeout and Underline Version

Rule 59.3-E4

59.3-E4)    In Metal Conduits: Common neutral conductors may be installed in the same metal riser conduits with related phase conductors, provided that the insulation of the neutral conductor is not less than that required of the phase wires and, further, that it is treated as a phase wire for the entire run between terminals.  Where the conduit installation metal riser conduit is an effectively grounded metal riser pipe, the reference to insulation of the common neutral need not apply, provided the neutral conductor is connected to both ends of the riser pipe and effectively, grounded.

Final Version

Rule 59.3-E4

59.3-E4)    In Metal Conduits: Common neutral conductors may be installed in the same metal riser conduits with related phase conductors, provided that the metal riser conduit is an effectively grounded.