Original Version

Rule 49.5

49.5    Insulators

A.    Line

Insulators, supports, clamps and other miscellaneous attachments shall be designed to withstand, with at least the safety factors specified in Rule 44, the mechanical stress to which they are subjected by conductors, wires or structures, under the loading conditions as specified in Rule 43.  Pin insulators shall effectively engage the thread of the pin for at least two and one-half turns.

B.    Guy

Guy insulators, including insulators in messengers, shall have mechanical strength at least equal to that required of the guys in which they are installed.

C.    Replacements (see Rule 44.2)

Strikeout and Underline Version

Rule 49.5

49.5    Insulators

A.    Line

Insulators, supports, clamps and other miscellaneous attachments shall be designed to withstand, with at least the safety factors specified in Rule 44, the mechanical stress to which they are subjected by conductors, wires or structures, under the loading conditions as specified in Rule 43.  Pin insulators shall effectively engage the thread of the pin for at least two and one-half turns.

B.    Guy

Guy insulators, including insulators in messengers, shall have mechanical strength at least equal to that required of the guys in which they are installed.

C.    Replacements (see Rule 44.2)

D.    Post

Post insulator units including insulator supports, clamps and other miscellaneous attachments shall have a cantilever strength determined in accordance with a paragraph 5.1.3 of the American Standard Insulator Tests, Publication No. C29.1-1961, or the latest revision thereof, equal to or greater than the product of the safety factors specified in Rule 44 and the mechanical stress to which they are subjected by conductors, wires, or structures under the loading conditions as specified in Rule 43.

Final Version

Rule 49.5

49.5    Insulators

A.    Line

Insulators, supports, clamps and other miscellaneous attachments shall be designed to withstand, with at least the safety factors specified in Rule 44, the mechanical stress to which they are subjected by conductors, wires or structures, under the loading conditions as specified in Rule 43.  Pin insulators shall effectively engage the thread of the pin for at least two and one-half turns.

B.    Guy

Guy insulators, including insulators in messengers, shall have mechanical strength at least equal to that required of the guys in which they are installed.

C.    Replacements (see Rule 44.2)

D.    Post

Post insulator units including insulator supports, clamps and other miscellaneous attachments shall have a cantilever strength determined in accordance with a paragraph 5.1.3 of the American Standard Insulator Tests, Publication No. C29.1-1961, or the latest revision thereof, equal to or greater than the product of the safety factors specified in Rule 44 and the mechanical stress to which they are subjected by conductors, wires, or structures under the loading conditions as specified in Rule 43.