Original Version
Rule 57.7
57.7 Use of Guard Arms and Coverings
Any guard arm which is required to be installed by the provisions of Rule 57.4-F shall be at least 4 feet in length (Rule 20.9-D) and parallel to and not more than 4 inches above the top of the cable or messenger. In lieu of the guard arm, suitable protective covering (Rule 22.2) at least 4 feet in length may be placed around the cable and messenger.
Double guard arms shall be used where such a messenger or cable is dead ended on or wrapped around a wood pole, at a vertical separation of less than 6 feet below unprotected supply conductors of other circuits of 750 volts or less. Portions of cables which take the form of a riser or a grounded lateral or vertical run shall be covered as specified in Rule 54.6-E for risers.
Strikeout and Underline Version
Rule 57.7
57.7 Use of Guard Arms and Coverings
Any guard arm which is required
to be installed by the provisions of Rule 57.4-F shall be at least 4 feet in
length (Rule 20.9-D
21.0-D) and parallel to and not more than 4 inches above the top
of the cable or messenger. In lieu of
the guard arm, suitable protective covering (Rule 22.2
22.8) at least 4 feet in
length may be placed around the cable and messenger.
Double guard arms shall be used where such a messenger or cable is dead ended on or wrapped around a wood pole, at a vertical separation of less than 6 feet below unprotected supply conductors of other circuits of 750 volts or less. Portions of cables which take the form of a riser or a grounded lateral or vertical run shall be covered as specified in Rule 54.6-E for risers.
Final Version
Rule 57.7
57.7 Use of Guard Arms and Coverings
Any guard arm which is required to be installed by the provisions of Rule 57.4-F shall be at least 4 feet in length (Rule 21.0-D) and parallel to and not more than 4 inches above the top of the cable or messenger. In lieu of the guard arm, suitable protective covering (Rule 22.8) at least 4 feet in length may be placed around the cable and messenger.
Double guard arms shall be used where such a messenger or cable is dead ended on or wrapped around a wood pole, at a vertical separation of less than 6 feet below unprotected supply conductors of other circuits of 750 volts or less. Portions of cables which take the form of a riser or a grounded lateral or vertical run shall be covered as specified in Rule 54.6-E for risers.