General Order 64-A

Section VIII

Detailed Construction Requirements For Communication Lines

(Class C Circuits)

86.6    Insulation.

Where insulators are used in guys, their values shall be calculated on the highest voltage carried at the level on the pole, tower, structure or cross arm nearest which the guy is attached and they shall conform to the following specifications:

A.    Material.

Insulators used on communication lines shall be of porcelain, glass or other equally suitable material as regards electrical and mechanical properties.

B.    Strength.  (See Rule 49.5-B.)

C.    Voltage Requirements.

Insulators shall be capable of withstanding the flash-over voltages given in the following table when under mechanical loadings to which they are subjected.

Insulators shall be tested under American Institute of Electrical Engineers’ specifications as a minimum.

* (See Rule 20.5-B.)

D.    Location.

(1)    Anchor:  Each anchor guy shall be equipped with an insulator so located that it shall, at all times, be at least 8 feet vertically below the nearest conductor and at least 8 feet vertically above the ground.  Excepted from this rule are:

Guys attached to or passing poles or structures supporting only communication conductors, provided no exposures of guys to supply circuits involved.  (See App.  G, Fig. 26.)

Guys attached to poles or structures not permanently grounded supporting supply conductors only in excess of 17,000 volts, provided no other exposures of guys to supply circuits are involved.  (See App. G, Fig. 27.)

Guys attached to permanently grounded metal poles or structures, provided such guys are maintained at a distance of at least 8 feet vertically from the nearest supply conductor of less than 17,000 volts on poles or structures not permanently grounded or 8 feet radially from the center line of any poles (other than those to which said guys are attached) carrying supply conductors of less than 17,000 volts on poles or structures not permanently grounded.  (See App. G, Fig. 28.)

Guys from the level of conductors less than 16 feet above ground requiring insulators shall have same located at not less than 8 feet or more than 10 feet vertically above the ground.  (See App. G, Fig. 29.)

(2)    Overhead:  Each overhead guys shall be equipped with two insulators, so located that one shall be at a distance of 6 feet to 9 feet, measured along the line of the guy from each point of attachment to pole or structure and both shall be at least 8 feet vertically above the ground.  Excepted from this rule are:

Guys between poles or structures, not permanently grounded, supporting only communication conductors, provided no exposures of guys to supply circuits are involved.  (See App. G, Fig. 32.)

Guys between permanently grounded metal poles or structures, provided such guys are maintained at a distance of at least 8 feet vertically from the nearest supply conductor of less than 17,000 volts on poles or structures not permanently grounded or 8 feet radially from the center line of any poles (other than those to which said guys are attached) carrying supply conductors of less than 17,000 volts on poles structures not permanently grounded.  (See App. G, Fig. 30.)

Guys between permanently grounded metal poles or structures and poles or structures (not permanently grounded) and said guys are in metallic contact with permanently grounded anchor guys, provided such guys are maintained at a distance of at least 8 feet vertically from the nearest supply conductor of else than 17,000 volts on poles or structures not permanently grounded or 8 feet radially from the center line of any poles (other than those to which said guys are attached) carrying supply conductors of less than 17,000 volts on poles or structures not permanently grounded.  (See App. G, Fig. 31.)

Guys between poles or structures, not permanently grounded, supporting supply conductors and said guys are in metallic contact with contact with permanently grounded anchor guys.  Such guys shall be equipped with one insulator, located 6 feet to 9 feet, measured along the line of the guy from the upper point of attachment, provided all permanently grounded sections of such guys are maintained at a distance of at least 8 feet vertically from the nearest supply conductor of less than 17,000 volts on poles or structures not permanently grounded, or 8 feet radially from the center line of any pole (Other than those to which said guys are attached) carrying supply conductors of less than 17,000 volts on poles or structures not permanently grounded.  (See App. G, Fig.  33.)

Guys less than 17 feet in length requiring insulators between poles or structures not permanently grounded, in which case on insulator placed equidistant from each support will be sufficient.

(3)    Truss:  Each truss guy, the lower end of which is not grounded, shall be equipped with two insulators, one which shall be located at least 8 feet below the lowest conductor and the other at least 8 feet vertically above the ground.  Where the lower end is grounded, the bottom insulator may be omitted.  Excepted from this rule are:

Truss guys on poles or structures, not permanently grounded, supporting only communication conductors, provided no exposure of guys to supply circuits is involved.  (See App. G, Fig. 26.)