Power in action Hellenic Cables

POWER IN ACTION

Hellenic Cables SA is one of the largest cable producers in Greece. Its cable products, which carry the trademark CABLEL®, include power cables up to 500kV, telecommunication and data transmission cables, enamelled wires and plastic and elastomer compounds. Joseph Altham reports on a company whose high voltage power cables are helping to meet the needs of Europe’s electricity networks.

Hellenic Cables is part of Viohalco SA, Greece’s largest metals processing group. Hellenic Cables traces its origins back to 1950, the year when Viohalco first started making cables. Later, in 1973, Hellenic Cables was created as a separate entity within the Viohalco group. Along with decades of experience, Hellenic Cables has a modern production plant employing stateof-the art technology.

The company successfully relocated its main factory from Inofyta to Thiva in 2003. The move gave the company more space, increased capacity and the opportunity to upgrade its equipment and develop high value added products. The focus of the Thiva factory is the manufacture of power cables, but the company has retained a smaller factory in Inofyta for the production of plastic compounds. In 1999, Hellenic Cables was able to buy out a major company and move into Romania. Its Romanian subsidiary, ICME ECAB SA, produces power and telecommunication cables and overhead conductors and employs over 500 people. Hellenic Cables has invested heavily in the Bucharest plant to equip it with modern machinery, and now has a 40 per cent share of the Romanian market.

Compounds

Power cables are the company’s most important product. However, plastic compounds are an integral part of the business, and the company’s ability to manufacture plastic and rubber compounds in-house helps it to stand out from the competition. With electricity, as with all forms of energy, safety is a vital consideration. For this reason, as the marketing manager at Hellenic Cables explained, the cable industry is tightly regulated to ensure quality and reliability. “Strict national and international standards apply to electricity cables. The standards lay down strict requirements for the type of conductor (aluminium or copper) to be used, and what sort of insulation and protection the cable will need, whether rubber or plastic. Industrial power cables need to have a second layer of protection in the form of a robust jacket or sheath. Protecting the cable demands a very specific type of compound, which has to meet the test requirements of the cable standards.”

The company developed its Pivinel range of PVC compounds for the insulation of power cables. In 2006, Hellenic Cables began to manufacture a special compound, used to make LSF (low smoke and fume) cable sheaths. The Retardel compound is halogen-free, meaning that the material will not give off toxic gases or dense smoke in the event of a fire. “Because we produce our own compounds, we can control all the properties that need to be customised,” says the marketing manager. “This allows us to deliver within short order times, and to satisfy the special demands of our customers.”

High voltage cables

Hellenic Cables has been able to draw on the know-how of major players in the industry. The company started making fibre optic cables in cooperation with Siemens in 1991, buying out Siemens’s share nine years later. In 2001, Hellenic Cables concluded a technical assistance agreement with the leading Japanese firm Furukawa Electric for the design and manufacture of high and extra high voltage cables. “Furukawa Electric provided us with valuable technical know-how,” says the marketing manager, “and with their help we were able to smoothly develop this technology without suffering setbacks.”

In 2003, Hellenic Cables began making high voltage (HV) cables (up to 150kV), using an insulation type known as XPLE (cross-linked polyethylene). The company started production of extra high voltage XPLE insulated cables in 2008. Besides the XPLE insulation, the company’s extra high voltage (EHV) 400kV cables also have a lead sheath or welded aluminium sheath to protect the conductor and screen, as well as an outer sheath made of high density polyethylene - HDPE. XPLE provides the insulation for modern HV and EHV underground electric cables. “The crosslinking of the polyethylene provides mechanical strength and can operate at high temperatures,” explained the Marketing Manager. “We have successfully completed a year long prequalification test for our 400kV cables. The cables have to meet the requirements of the PQ test before they can be made commercially available. These tests were carried out at our own testing facilities in Thiva.”

Markets and prospects

According to the marketing manager at Hellenic Cables, there is a growing trend for utility companies to use HV and EHV underground

cables in preference to overhead power lines, especially in populated areas. Overall, the long-term prospects for Hellenic Cables appear secure, as few people expect Europe’s electricity consumption to decline in the future. High voltage cables are also needed to enable European countries to upgrade their ageing power networks.

As Europe strives to generate a greater proportion of its electricity from wind farms and solar power plants, renewable energy has presented the company with an exciting new source of demand. As the marketing manager points out, the electricity that is generated from renewable sources has to be transported before it can finally reach the consumer. In particular electric energy generated from windfarms that are offshore or on islands require submarine cables for transmission and this is an area for product development that interests Hellenic Cables.

Another consideration favouring Hellenic Cables is the growth of the European electricity market. Electricity is now heavily traded between different European countries, and high voltage cables facilitate the transport of electricity across Europe’s borders. n