OPGW SAG AND TENSION LIMITS BASIC INFORMATION AND TUTORIALS

The following are recommended as minimum controls to be used in preparing sag and tension charts for OPGW as recommended by IIEE STD 1138-1994:


a) OPGW sags should be such that the tensions do not exceed the limits for open supply conductors, which are given in the latest edition of the National Electrical Safety Code (NESC) or appropriate national code(s) for the country where installed.

These limitations are based on the use of recognized methods for reducing the likelihood of fatigue failures by minimizing chafing and stress concentrations.

b) Sag and tension recommendations regarding vibration protection should be obtained from the OPGW manufacturer or from other sources knowledgeable in the field of vibration protection of overhead cables.

c) In addition, it is known that some types of cable construction exhibit increased attenuation of the optical signal at tensions, which are permitted by the National Electrical Safety Code (NESC) or appropriate national code(s) for the country where installed. This may be a factor in the selection of the maximum design tension.

d) It is recommended that tension limits for a specific application be chosen through a coordinated study that should include the requirements of the user, recommendations from the cable manufacturer, and recommendations from the manufacturer of all supporting hardware.