These cables are used to transit electricity between transformer stations and receivers, to supply households and in other places where cable routing in the ground is restricted or the cost of an underground line is high. A working core of overhead insulated cables is carried out in the construction of single- and multi-wire, from aluminium or aluminium alloy. Insulation can be made of cross-linked polyethylene, resistant to flame spreading.
The maximum temperature of a core for long-term load: 90°C
The maximum temperature of working core for short circuit lasting 5 seconds: 250°C
Temperature of cable installation: up to -20°C
Product examples:
EX based on NEN 73.77 - aluminium (AL) cores in the isolation of thermoplastic polyethylene (PE)
ABC based on BS 7870-5 - aluminium (AL) cores in the isolation of cross-linked polyethylene (XLPE)
ABC based on NF C 33-209 - bundling cables with aluminium cores or most with a combination of aluminium cores and bearing alloy (Al-Mg-Si), insulated with cross-linked polyethylene (XLPE)
XOO-A; XOO/O based on Jus N.C5.250 - phase aluminium cores, zero made of aluminium alloy Al-Mg-Si, insulation with cross-linked polyethylene (XLPE)
AMKA based on SFS 2200 - phase aluminium cores, zero made of Al-Mg-Si, insulation with cross-linked polyethylene (XLPE)
NFA2X based on DIN VDE 0274 - aluminium cores in insulation with cross-linked polyethylene (XLPE)
AsXSn based on ZN-TF207:2007 - aluminium cores in insulation with cross-linked polyethylene (XLPE)
Overhead high-temperature cables - middle voltage lines with cables insulated with cross-linked polyethylene in the system of PAS AALXSn 20/24 kV PAS: SFS 5791.
Overhead insulated cables with multi-wire cores made of aluminium alloy ensure the highest possible mechanical properties while maintaining high electrical parameters. They are used in the medium voltage electricity transmission system. Due to insulation made of cross-linked polyethylene, the usable properties are improved compared to bare overhead cables, including:
- momentary contact with each other due to wind, cables installed in parallel, this does not damage the line, or disrupt in energy supply,
- do not involve the risk of electric shock of people and animals and fire in the event of unexpected contact of a cable with branches of trees broken during extreme weather conditions,
- for this reason, they can be installed in forests and wooded areas in a narrow strip of cut down trees (in the case of bare cables, a strip of cut down trees is larger due to the need to minimise the risk of contact with of tree branch with the line).
Products examples:
AALXSn 20/24 kV PAS: SFS 5791
- CCSTWK GREENPAS: a new generation of electricity conduits to the overhead lines based on EN 50397-1
GREENPAS cables produced by TF Kable have a unique triple layer structure of insulation. The core is made of Al-Mg-Si alloy, which is sealed with special swelling powder that acts as a barrier preventing from longitudinal moisture migration. A semi-conducting layer imposed on a core is responsible for uniform distribution of the electric field. The next insulating layer is thermoplastic polyethylene LDPE. The external cover is made of polyethylene HDPE, thermoplastic, resistant to UV and atmospheric factors. Due to the use of thermoplastic polyethylene, it is possible to fully recycle cable materials after use. Compared with traditional PAS cables (with one insulation layer), GREENPAS cables, due to three-layer insulation, are characterised by higher insulation properties and resistance to partial discharge and slippery discharge, and therefore are more reliable than PAS cables, and provide a longer period of safe operation.
Products examples:
CCSTWK – GREENPAS based on EN 50397-1