ADSS
AEI compounds experience in anti-tracking materials began in the early 1980's when work was instigated to develop a sheathing material suitable for all di-electric self supporting (ADSS) fibre optic cables.
This type of telecommunications and control cable can exploit the considerable economic advantages offered by the installation of existing high voltage power lines over all types of terrain and competes with other technologies such as optical fibre ground wire (OPGW) and helically wrapped optical fibre cables.
OPGW cables are overhead conductors which have optical telecom fibres incorporated within them, and, as their name implies, are generally the most expensive route and utilizied on new or re-strung power lines.
In helically wrapped optical cables, a motorised device runs along the exisiting earth conductor wrapping the cable around it. Polyethylenes, or, in some cases UV stabilised XLPE polymers, are generally used in the cable sheath.
ADSS cables are fully insulated self-supporting cables installed on 132-500 kV systems at spans of up to 500m. The cables are suspended within the electical field of the high voltage overhead lines and can be installed on the live lines without power outage. Emergency installation or repair of ADSS cables is also easily facilitated.
By comparison to other designs described ADSS cables, by virtue of their electric field position, are subjected to induced voltages on the cable surface. In wet and polluted conditions surface discharge activity can occur with sufficiently high induced voltages leading to surface hydrophobicity and dry banding. Large voltages can then develop resulting in tracking or erosion of the sheath material.
SX524 has been designed to meet the demands of a sheath for ADSS cable processing resistance to surface tracking and erosion, UV resistance, toughness and stress crack resistance. Crosslinking is essential to meet these demands. Using the silane or Sioplas technique has proved to be ideal in that being a low temperature and pressure method it does not cause damage to the optical fibres in the cable.
Grade available
|
Density |
Tensile |
Elongation |
ASTM G53-84 |
Data |
| SX524:CM424-1 Tough electrical tracking resistant silane crosslinkable sheathing compound | ||||
|
1.40 |
10 |
300 |
Pass |
|
Please note that all of the silane crosslinkable grades are shown as a system with a graft and a catalyst. These are normally used in the ratio of 95:5. The most common catalyst masterbatch is shown in the table but there are others available which helps us to more accurately match your property requirements and processing conditions.
