High-voltage cable 60-500 kV

The main Estralin activity is production of high-voltage cable 60-220 kV and delivery of cable systems 60-500 kV.

Estralin offers XLPE insulated single core power cables for long-distance power transmission in distribution and transmission networks for application under different conditions.

Completely water-sealed HDPE sheathed cable is used for underground transmission, while for the installation under water Estralin offers cable with additionally applied round wires armour.

Cable with outersheath from flame retardant and halogen free PE composition is used for installation in the cable’s ducts or outdoors.

Cable design


* The conductor is used for the transmission of electric current. The material, shape and cross-section of the conductor defines the current-carrying capacity of the cable line.

- Cooper
- Aluminum
Possible variants
- Round stranded
- Segmented (Milliken)
Cross-sections of round conductors
185 – 1600 mm2
Cross-sections of segmented conductors
1000 – 2500 mm2
Inner semi-conductive screen

* The inner semi-conductive screen provides equal distribution of the electric field at the boundary of the conductor and the insulation.

XLPE insulation

* XLPE insulation is the main insulating element of 60-500 kV XLPE cables design. Insulation is a layer of XLPE with high dielectric strength. Insulating XLPE shall withstand the effects of electric field both in operational and transient conditions.

Outer semi-conductive insulation screen

* The conductive screen provides equal electric field distribution in cable insulation.

Optical fiber modul

* Optional optical fiber modules (FIMT) can be embedded into the wire screen for cable temperature control purpose.

Separation layer

* Separation layer is made of water-blocking semi-conductive tapes that serve as a moisture barrier. It is required to prevent the moisture spreading if the cable sheath is damaged (longitudinal sealing) as well as to ensure that the outer semi-conductive screen is separated thermally and mechanically from the cable wire screen.

Wire screen

* The main purpose of the wire screen is an equal distribution of potential across the cable insulation and transmission of short-circuit currents.

- copper
- aluminum alloy
Separation layer

* Separation layer is a layer of conductive water-blocking tapes that serves as a thermic separator between metal screen and outersheath and a water barrier (longitudinal sealing).

Longitudinal sealing

* Longitudinal sealing prevents moisture from entering through the outersheath.

- polymer coated aluminum foil which is firmly bonded with the outer sheath
- lead sheath
Outer sheath

* The outer sheath is required for insulating the wire screen from the ground and protecting the cable from mechanical damage during installation and maintenance as well as from any adverse external effects.

- halogen-free PE compound


Cooper conductorWithout marking
Aluminum conductorA
Round stranded conductorRM
Segmented conductorRMS
XLPE Insulation 2X
Copper S
Aluminum SA
Longitudinal water sealing (F)
Longitudinal and radial water sealing (FL)
Optical fiber in the screen LWL
Aluminum alloy wires armour AWA
Lead sheathK
PVC sheathY
HDPE sheath2Y
Halogen free flame-retardant sheathH

* Design and marking of the cable can be changed by the implementation of new solutions.

Marking examples:
A2XS(FL)2Y 1×300RM/50 – 64/110 kV

Quality control

Estralin pays special attention to product quality control according to the standards of the International Electrotechnical Commission (IEC): IEC 60840 at rated voltage of equipment above 30 kV to 150 kV, IEC 62067 at rated voltage of equipment above 150 to 500 kV.

Determining the compliance of cable parameters and its accessories with the standard and internal quality requirements are carried out in several stages:

  • Operating control is performed during and immediately after every production step;
  • Routine tests include measurement of the PD level and alternating voltage testing of each delivery length of the manufactured cable.
  • Type tests are carried out with every stage of design and before approval of new materials or technologies.
  • Sample tests are carried out on the cable production samples at certain intervals of time.

Estralin quality control system provides total quality control of each delivery length, this is confirmed by the test reports for every order.
Quality control system at all-production stages allows ensuring a continuous monitoring of cable quality and of the efficiency of promptly taking preventive measures for the quality improvement.

Estralin has certificates which state that their quality control system complies with requirements of ISO standard ISO 9001:2015, ISO 14000:2015, ISO 45001:2018.

XLPE power cable 300-500 kV

The company offers a range of products for extra high-voltage cable systems 300-500 kV.

For more information of the product range, please contact us info@estralin.com