General Order 64 (Rule 66)

Section VI

TABLE 7 Specification for Insulators for Guys
Maximum voltage of supply lines on poles to which guy is attached	Minimum flash-over voltage of strain insulators
	Dry	Wet – 1-5 inch rain per min.
750 volts	5,000	3,500
2,300 volts	7,500	4,500
4,000 volts	10,000	6,000
6,600 volts	14,000	7,000
7,500 volts	16,000	8,000
11,000 volts	20,000	11,000
15,000 volts and above	25,000	15,000

(b) Guy insulators shall preferably be so constructed that guy wires are interlocking and shall have a mechanical strength at least equal to that of the guys in which they are installed.

(c) Insulators in Ground Guys: A ground guy shall be defined as a guy which has its lower end permanently grounded; it is commonly called a sidewalk, truss, or an anchor guy.

Note - Guy wires in metallic contact with metal anchor rods having a minimum diameter of 5/16 inch and embedded in the ground to a minimum depth of 4 feet shall be considered as permanently grounded.

1. Each ground guy attached to any pole, crossarm or structure carrying supply conductors of 17,000 volts or less shall be equipped with an insulator, so located that same shall at all times be maintained at least 8 feet vertically above the ground. (See Appendix E, Fig. 16A.) (See Par. (e)1 for exception to this rule.)

2. Each ground guy attached to any pole, crossarm or structure carrying supply conductors in excess of 17,000 volts shall be equipped with an insulator of the interlocking type having the highest voltage specification (see Table 7, Rule 66 (a) and so located that same shall be at all times maintained at least 8 feet below the nearest supply conductor and at least 8 feet vertically above the ground. (See Appendix E, Fig. 16B.) (For exceptions to this rule, see Par. (e)4 (Appendix E, Fig 19B) and 5.)

(d) Insulators in Overhead Guys: Overhead guys shall be considered as those guys, commonly called span guys, extending from pole or crossarm to pole or crossarm to guy stub.

1. Each overhead guy attached to any pole, crossarm or structure carrying supply conductors of 17,000 volts or less shall be equipped with two insulators, one insulator to be located not less than 6 feet nor more than 9 feet (measured along the line of said guy) from the upper point of attachment, the other to be not less than 6 feet nor more than 9 feet (measured along the line of said guy) from the lower point at attachment and maintained at least 8 feet vertically above the ground. (See Appendix E, Fig. 17A.) (For exception to this rule, see Par. (e) 4 (Appendix E, Fig. 19B).)

2. Each overhead guy attached to any pole, crossarm or structure carrying supply conductors in excess of 17,00 volts shall be permanently grounded and shall be equipped with an insulator of the interlocking type, having the highest voltage specifications (see Table 7, Rule 66(a)) and so located that same shall not be less than 6 feet nor more than 9 feet (measured along the line of said guy) from the lower point of attachment and shall at all times be maintained at least 8 feet below the nearest supply conductor and at least 8 feet vertically above the ground. (See Appendix E, Fig. 17B.) (For exceptions to this rule, see Par. (e) 2 (Fig. 18A), 3 (Figs. 18B and 19A), 4 (Fig 19B) and 5.)

1. When truss guys attached to poles or structures carrying supply conductors of 17,000 volts or less are not permanently grounded, they shall be equipped with two insulators, the upper insulators to be maintained at least 8 feet below the nearest supply conductor, and the lower insulator to be maintained at least 8 feet vertically above the ground. (See Appendix E, Fig 16A.)

2. When an overhead guy is attached to a wooden pole, crossarm or structure carrying supply conductors in excess of 17,000 volts and said guy crosses over or under telephone, signal or other similar circuits for public use, insulators or the interlocking type shall be employed therein. Two insulators shall be located with a distance of not less than 6 feet, nor more than 9 feet (measured along the line of said guy) from one point of attachment on the pole, crossarm or structure carrying said conductor in excess of 17,000 volts and one insulator to be likewise located from the other point of attachment when same is attached to a pole or structure carrying supply conductors of 17,000 volts or less. Should both points of attachments be on poles, or structures carrying supply conductors in excess of 17,000 volts, then four insulators shall be used, two insulators to be located as given above from each point of attachment. In all cases such overhead guys shall be permanently grounded and the insulator or insulators, as the case may be, at the lower point of attachment shall be so located that same shall not be less than 6 feet nor more than 9 feet (measured along the line of said guy) from the lower point of attachment and shall at all times be maintained at least 8 feet below the nearest supply conductor and at least 8 feet vertically above the ground. (See Appendix E, Fig. 18A.) (For exceptions to this rule, see Par. (e) 3 (Fig. 19A), 4 (Fig. 19B) and 5.)

Note - Guys attached to poles carrying supply conductors in excess of 17,000 volts should not cross above where it is practicable to cross below Class “S” lines.

3. When the insulator or insulators, as the case may be, and as required in Par. (d) 2 (Fig. 17B) and (e) 2 (Fig. 18A), can not, because lack of clearance above roads or other obstructions, be maintained at least 8 feet below the nearest supply conductor and at least 8 feet vertically above the ground, each overhead guy in the case of Par. (d) 2, shall be equipped with two insulators, of the interlocking type, having the highest voltage specification, which shall be located as in Par. (d) 1 (Fig. 17A), and each overhead guy in the case of Par. (e) 2, shall be equipped with three of four insulators (depending upon the voltage of the supply conductors) located as in Par. (d) 1. In addition such overhead guy shall be metallically connected to the upper end of an anchor guy which shall be equipped with a similar insulator located at least 8 feet below the nearest supply conductor and at least 8 feet vertically above the ground. (See Appendix E, Figs. 18B and 19A.) (For exceptions to this rule, see Par. (e) 4 (Fig. 19B) and 5.)

4. When an overhead guy wire is in grounded contact with a ground wire or an anchor guy and said ground wire or anchor guy is attached to a pole or structure not carrying supply conductors, such construction shall be treated as one continuous grounded guy and only the insulator or insulators as the case may be, at the upper point of attachment, and as located in Par. (d) 1 (Fig. 17A) and (e) 2 (Fig. 18A) or 3 (Figs. 18B and 19A) shall be held to be necessary. (See Appendix E, Fig. 19B.) (For exceptions to this rule, see Par. 5, following.)

5. When guy wires are attached to a pole or structure of metal or other conducting material, supporting only conductors in excess of 17,000 volts no insulation shall be required at any point in the guy wire.