Previous Code

Next Code

 

General Order 64-A

 

Section IV

 

Strength Requirements For All Classes Of Lines

 

49.3   Pins and Conductor Fastenings

 

A.    Material

 

(1)    Pins: Insulator pins shall be of galvanized steel, galvanized iron or other corrosion-resisting metal or of locust or other suitable wood.

 

(2)    Fastenings:  Conductor fastenings shall be of galvanized steel, galvanized iron or other corrosion-resisting metal.

 

B.     Size

 

(1)    Wood Pins: The minimum diameter of the shank shall not be less than 1 inches.

 

(2)    Metal Pins: The minimum diameter of the shank shall not be less than inches.

 

(3)    Tie Wires:  The minimum size of tie wire for a particular gauge of line conductor is given in the following table:

 

Table 6

Line material

Conductor gauge

Tie wire gauge

Copper

(A.W.G.)

6 and smaller

Size of line conductor

4

6

2 and 0

4

00 and larger

2

Iron and Steel

B.W.G

9 and smaller

Size of line conductor

8

Not smaller than 9

4 and 6

8

 

C.    Strength

Insulator pins shall be able to withstand the loads to which they may be subjected with safety factors at least equal to those of Rules 44, Table 4.

 

(1)    Tensions:  For conductor tensions up to 2000 pounds per conductor which are supported on pins and insulators, double pins and insulators with tie wires, or equivalent fastenings, will be considered as meeting the strength requirements of Rule 47.4 and 47.5.

 

(2)    Longitudinal Stresses:

 

a)    Pins and Conductor Fastenings:  Where longitudinal stresses are normally balanced, pins and conductor fastenings, other than tie wires, shall have sufficient strength to withstand as a minimum a stress of 700 pounds.

A standard 1 by 9 inch locust pin provides strength up to 1000 pounds tension in the conductor, with the conductor 3 inches above the cross arm.

 

b)    Tie Wires:  Tie wires and fastenings shall have no sharp edges at points of contact with conductors, and shall be applied in such manner as not to damage the conductor.

Tie wires shall be installed in such a manner that they will securely hold the line conductor to its supporting insulators.  This will permit without slipping of conductor an unbalanced pull equal to the following percentage of the allowable tension of the conductor, to a maximum of 500 pounds:

 

Supply line tie wires

40%

Communication line tie wires

15%

 

 

D.    Replacements (see Rule 44.2)