Introduction to ADSS fiber Cable
All-dielectric self-supporting (ADSS) cable is a type of optical fibre cable that is strong enough to support itself between structures without using conductive metal elements. It is widely used by electrical utilities for live-line installation, installed along existing overhead transmission lines and often sharing the same support structures as the electrical conductors.
The cable structure is as below:
Fibers are positioned into a loose tube made of high modulus plastics.
Normally there are five or six tubes( or fillers) in total. these tubes are filled with a water-resistant filling compound and stranded around an FRP (Fiber Reinforced Plastic) which work as a non-metallic central strength member, Then covered with thin PE (polyethene) inner sheath. After a stranded layer of aramid yarns are applied over the inner sheath as a strength member, the whole cable is completed with PE or AT (anti-tracking) outer sheath.
For overhead power lines under 110kV, PE outer sheath is applied.
For power lines equal to or over 110kV, AT outer sheath is applied.
Span length (100m ~ 500m)
Rated tension strength （RTS）: The RTS parameter of ADSS optical cable is an important basis for hardware configuration (especially tensile hardware) and calculation and control of safety factor.
Max. allowed tension (MAT): The MAT is a piece of important evidence to characterize the stress-strain characteristics of the ADSS optical cable. Under this stress, the fiber deformation should not be more than 0.05% (rolled) and not more than 0.1% (core pipe) without additional attenuation. Generally, it is 40% RTS.
Annual average running tension(EDS): The annual average stress is sometimes called the daily average stress, it refers to the wind and no ice and the annual average temperature, the theoretical calculation of the load cable tension, can be considered as the ADSS in the long-term operation of the tension average (should) force. EDS is generally (16 ~ 25)% RTS.
Methods of Installation:
1. “Mobile Cable Reel” method
Generally recommended for span < 50 m, This method is only available on the roadside of the pole, with no tall obstacles between the road and the poles. It enables a fast installation with a limited strength force on the cable.
2. “Static Cable Reel” method
Generally recommended for span > 50 m The stationary reel method is used in urban areas where there is no vehicle access.