5374 High Voltage Cables

High Voltage Cables

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Nexans Norway AS

Cable installation in Lofoten in 1961

For more than eighty years, Nexans Norway AS – formerly Standard Telefon og Kabelfabrik AS (STK) – has been

the principal supplier of power cables in Norway. These eight decades have seen enormous development of the

country´s hydropower resources. Today, Norway´s consumption of electricity per capita is higher than that of

any other country in the world.

Most of the hydro-electric power stations are located in the mountains, whereas the main centres of population

are in the lowland and coastal regions. Consequently, hydropower development has been accompanied by the

growth of an extensive power grid for the transmission and distribution of electricity.

Underground and submarine cables are important components in the power grid. Over the years, Nexans

Norway has acquired vast experience in manufacturing and installing power cable systems.

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Nexans Norway AS

Cable technology in the forefront

Design and engineering

XLPE cables

A few examples of installations

Oil-filled cables

Cable design


Development for future needs

Research and development

Cable accessories and installation services

A full range cable supplier

Cable technology in the forefront


The Halden plant

The Halden plant is the main plant of Nexans Norway and is thecompetence center for high-voltagesubmarine power cables andumbilicals within Alcatel´s cableactivities. At this plant, research anddevelopment are carried out on a comprehensive array of powercables.

The plant, located on the Oslofjord,was built for the production of thecompany´s first Skagerrak cables inthe early 1970´s. Since its erection, it has continuously been enlarged andupgraded in order to accommodatedevelopments in the field of paper-insulated high-voltage cables for ACand DC applications, as well as for the production of high-voltage XLPE(cross-linked polyethylene) insulatedcables, composite cables andumbilicals for the offshore industry.With a flexible layout and the mostmodern and efficient productionmachinery, the Halden plant suppliesthe most competitive cable systemsolutions to power utilities and theoffshore industry the world over.

Paper-insulated cables

The Halden plant is equipped forhandling cables of extra long lengthand heavy weight. The plant´s layoutand processes are designed to meetall special manufacturing andhandling requirements for large, high-voltage cables and umbilicals, andthe facility is currently able to producecables with conductors up to 2,500mm2, and paper-insulated cables forvoltages up to 765 kV AC.

XLPE insulated cables

In 1994, an entirely new productionline for XLPE cables was put intooperation.

The extrusion of XLPE is performed in a tower over 100 meters high. The extrusion of the conductor screen,insulation and insulation screen isperformed in a single operationutilizing four extruders and oneextruder head. The curing andcooling take place in a dryatmosphere of pressurized nitrogen.

Special attention is given to thehandling of materials, particularly inrespect to cleanliness. The rawmaterial is fed into the extruderthrough a completely closed system.In the manufacturing of high-voltagecables, a special super-clean grade ofmaterial is employed in order toensure the highest degree of purity.


Design and engineering

Power transmission systems are of vital importance, and it is

essential that they should function reliably year in and year out.

Since 1915, when we entered the power cable field, we have

been continuously engaged in cable production and the planning

and construction of power links spanning some of the most

difficult terrain in the world – trackless mountains, deep fjords

and wide expanses of open sea. In these projects we have

gained unequalled experience, which has helped us to devise

efficient and reliable designs and processes to the benefit of our

customers.

Nexans Norway offers a completerange of cable designs - oil-filled, mass-impregnated and XLPEinsulated for voltages from 1 kV to525 kV. We also supply a full rangeof cable system accessories includingjoints and terminations. We canundertake complete deliveriesincluding cable laying and electricalinstallation with full turn-keyresponsibility.

Public utilities all over the world nowlook to Norway for high voltagecables and for the solution of theirproblems in designing complete cablesystems. They know that NexansNorway means professionalperformance.


Engineering

Nexans Norway´s standard range ofcables and accessories are designedin accordance with national andinternational specifications, but weare fully prepared to design andsupply cable systems to customerrequirements.

In order to make the appropriatechoice of technical solution, thefollowing parameters should be givenas early as possible:

1. Rated voltage.2. Maximum operating voltages.3. Insulation level (impulse withstand

voltage).4. Short-cut circuit current: Transient

value and steady state value (root mean square) referred to a specificduration.

5. Transmitted power at rated voltage.6. Sketch giving dimensions, showing

layout and profile of the complete cable alignment.

7. Method of laying, thermal conditions, site conditions.

8. Standards.

Adjustment to local conditions andspecific installation sites is ourspeciality, based on our experiencefrom all over the world.

Turnkey capability

Nexans Norway will design a totalcable system to fit any customer need,and will take full responsibility for itsfunctioning. The company completesthe entire job – start to finish – fromerecting the termination site, trenches,foundations and buildings asrequired, to completing all electricalinstallations necessary.

Nexans Norway employs an engi-neering staff of some 250 specialistsin the design and installation depart-ments and in its laboratories. The company offers a wealth ofexperience gained from research anddevelopment put to test during projectexecutions around the world.

For any high-voltage cable project,Nexans Norway is the natural choiceas a turn-key partner.

Quality

Nexans Norway has establishedquality systems to ensure that deliveriesmeet agreed specifications andstatutory requirements, and satisfy theneeds of customers and internal users.The quality systems used in allactivities leading to the delivery ofproducts and services are certified byan accredited body (DNV) to conformto the standard BS EN ISO 9001: 1994.

Health, safety and environment

It is the policy of Nexans Norway toconduct all operations in accordancewith the best-known safety practices inorder to prevent accidents. This policyis relevant to personnel, environments,products and working equipment. Allactivities will be performed incompliance with prevailing legislationregarding health, safety and workingenvironments.

Although the prime responsibility forsafe operation rests with management,all Alcatel units consider the promotionof accident prevention and healthpreservation to be a major priority foremployees at every level. Therefore,awareness programs and a positiveattitude towards safety are importantfor all members of staff andmanagement.

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8

XLPE cables


In 1967 the first power cables with XLPE (cross-linked poly-

ethylene) insulation were installed in Norway for voltages of

12 and 24 kV replacing power cables insulated with PVC

(polyvinylchloride), polyethylene and mass-impregnated paper.

Experience in design, development and service rapidly proved

their reliability. For 12 and 24 kV XLPE cables the statistics show

approx. 0.09 failures per 100 three-phase circuit km per year;

a remarkably low figure compared with other countries. Also for

higher voltages the service experience is very good. This fact

together with research and development of materials and

processes has shown that technology is ready for cables at

420 kV and even higher voltages.

XLPE cables

The basic advantages of XLPEinsulated power cables may besummarized as follows: Because ofthe cross-linking the XLPE insulationcan be designed for a maximumconductor temperature of 90° C anda short circuit temperature of 250° C.The extruded insulation has excellentelectrical properties including lowdielectric losses and allow use ofsimplified solutions for joints andterminations compared to oil filledcables. Thanks to the elimination of aliquid impregnant the XLPE cables arewell suited for cable routes withdifferences in elevation requiring onlystandard terminations at both ends.Good mechanical properties andlight weight compared with oil filledcables simplify the installation work.

The key process in XLPE cablemanufacture is the extrusion of theinsulation system. Ever since theintroduction of XLPE insulated powercables in 1967 Nexans Norway hasapplied the insulation in a verticalextrusion line. In the beginning theconductor screen and the insulationwere extruded in a tandem operationwith cross-linking process based onsteam curing and water cooling. In 1979, as a result of developmentin process and material technology, a new vertical extrusion line wasinstalled incorporating triple extrusionof conductor screen, insulation andinsulation screen in one extruder head.


Curing and cooling was changed totake place in a dry atmosphere ofpressurized nitrogen. Today NexansNorway operates a vertical linewhere the insulation system is extrudedon to the conductor by four extrudersfeeding the material into one extruderhead.

Special attention is given to materialhandling, particularly as regardscleanliness and temperature duringstorage. A special super clean gradeof material which is used to ensure thehighest degree of purity, is fed to theextruders in a completely closedsystem.

The interface between the insulationand the two screens is of vitalimportance for the quality of theinsulation system – the more so withincreasing voltage levels. The interfacemust be smooth with a good bondbetween the layers. Even smallprotrusions may drastically reduce theelectrical properties of the insulationsystem. The introduction of the tripleextrusion tools of our own designtogether with optimal process controlensures smooth interface and therebyexcellent electrical properties.

Cable design

Conductor:Underground XLPE cables used inNorway normally comprises astranded, compacted aluminiumconductor. For export markets copperis the more common conductormaterial and for larger conductors thesegmented type of conductor(Milliken) is prevailing.

Insulation:The insulation system consists of aconductor screen, the insulation layerand an insulation screen, all layersextruded in one operation.

Screen:For underground cables the screenconsists of round copper wiresprotected with an overall PE or PVCsheath.

Water blocking:To protect the cables against ingressof water in case of damage thecables are provided with water-blocking material in the conductorand swelling tapes between the cablecore and the metallic sheath.

Metal sheath:If required the cable core is protectedby a metal sheathing - either anextruded lead sheath or a metal/PEfoil as a water barrier.

All submarine cables for voltagesabove 36 kV are provided with anextruded lead sheath and the outerprotection for underground cables isnormally PVC or PE sheaths.

Standards and testing:High voltage cables insulated withcross-linked polyethylene are normallytested at four levels:

a) Type testb) Routine testc) Special testd) Testing after installation

All these tests are routinely performedaccording to IEC 840 for servicevoltages from 36 to 420 kV.However, at customers´ request weare prepared to test according toother standards such as AIEC, IEEE orcustomer specifications.

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With regard to undergroundinstallations XLPE insulated powercables operating at voltages up to 72 kV had been installed already in1971. 40 phase-km of 72 kV XLPEcables were installed under onecontract as early as 1974. Asexperience grew, the advantages ofXLPE cables were increasinglyacknowledged, and in 1976 the first145 kV cable was installed. Fouryears later, in 1980. The voltagerange was increased to 300 kV. Fourinstallations at this voltage level arenow in operation in Norway.

Bergen City.In the city of Bergen, 78 km of 145kV underground directly buried cableswithout metal sheath were installed inthe period 1982-1989. Conductordimensions range from 400 to 1200mm2 compacted aluminium. Themajority of these cables are 1200mm2. This double circuit cable systemprovides one of the main electricitysupply routes to the city.

Oslo City.A similar installation in Oslo wascompleted between 1987 and 1990.The 145 kV cables, of total length 45km, were designed with a 1200 mm2

conductor, water-blocked with acompound and with a lead sheathapplied over a swelling tape.

USA.For Southern California Edison Co.,Nexans Norway has been anapproved supplier of 69 kV XLPEcables since 1983. Some 90 km ofcables with 1750 kcmils aluminiumconductor in accordance with AEICCS7 have been delivered so far.Nexans Norway has also beenapproved as a supplier of 115 kVXLPE cables and received its firstorder for such cables from SCE in1991.

Indonesia.In 1983 Nexans Norway installed150 kV XLPE insulated power cablesin transformer stations in Jakarta,Indonesia. Cables and accessorieswere installed by Nexans Norway'sown jointers.

Zimbabwe.In 1987, 88 kV XLPE insulated powercables were supplied to the CentralAfrican Power Corporation, CAPCO,Zimbabwe. These cables wereinstalled by CAPCO´s jointers.

Taiwan.In 1991 and 1994 a total of 8,4 km170 kV XLPE cables and 57 GISterminations were installed in the NanPu Power Station in Taiwan (in co-operation with Siemens AG).

To date, Nexans Norway has manufactured more than 50.000 phase-km of XLPE cables, ranging

from 12 to 300 kV, for use in Norway. Nearly 2200 km are for voltages higher than 24 kV.

Norway's first 300 kV XLPE insulated cable link was commissioned as early as in 1980. The worlds

largest submarine XLPE cable has been manufactured and installed by Nexans Norway in 1995

between the mainland and an offshore oil platform at the Troll field.



India.In 1996 and through 1997 NexansNorway supplied some 20 km of 220kV XLPE underground cables to TataElectric Power company in Bombay,India.

Submarine cables.Although the majority of XLPE cablesin Norway are laid underground, wehave completed many installations ofmore specialized types, mainlysubmarine links.

As early as 1971 a 900 m submarineXLPE cable, rated at 12 kV, was laidacross the Tromsøsund in NorthNorway. This cable, which had nometal sheath, was retrieved forlaboratory examination after 10 yearsin service. When subjected to testingby short term AC, DC and impulsevoltages, no significant reduction inthe breakdown voltage could bedetected, as compared with a newcable.

A 72 kV three-core cable submarinecable with individual lead sheaths oneach core was installed in 1977. In1981 a 14 km 24 kV three-core XLPEinsulated submarine cable wasinstalled in one single length. Twoyears later a 18 km cable of a similardesign was installed. Over the yearssome 1100 phase-km of submarinecables have been installed, 44installations have been for voltagesfrom 36 to 145 kV.

The first 145 kV XLPE insulatedsubmarine cables were installed in1981. In 1982 and 1983 two moreinstallations were performed. Thethree 1200 m single-core cables forthe first project were designed withlead sheath as a water-impermeablebarrier. For the other project with aroute length of 1000 m the customerdid not require a lead sheath. No problems have occurred duringthe service of either project. Up tonow Nexans Norway has performed10 submarine cable installations at145 kV.

Fairly early the XLPE insulatedsubmarine cables were adapted bythe offshore industry. In 1981 a 7 kmthree core cable at 35 kV wasinstalled for Texaco Inc. Between twoplatforms in Santa Barbara channel inCalifornia, U.S.A. In 1982 2 lengthsof 12 kV cables were laid between 3platforms off the west coast of Africafor Saga Petroleum Benin Inc.

In 1983, a 20-km 12 kV three-corecable incorporating control cableswas installed at the Frigg offshore oiland gas field in the North Sea to linkthe unmanned control station at theNorth East Frigg field to the mainFrigg field platform. Because theunmanned control station wasdesigned as a single-point mooredtower, the cable had to be designedto withstand the relative movement ofthe base structure of the tower and the

seabed, approx. 5 million bendingcycles per year. No failure hasoccurred since installation.

In 1987, two 24 kV submarine three-core cables approx. 4 km in length,with integrated fibre-optic elements,were installed between two oilproduction platforms in the NorthSea, Gullfaks A and B.

A number of XLPE insulated submarinecables have been supplied to theoffshore fields in the North Sea,Malaysia and Saudi Arabia. Amongthe special installations was the bigdynamic composite cable for theVeslefrikk field and the worlds longestXLPE insulated submarine cable forthe Troll field.

This three-core 52 kV cable wasinstalled between the Troll offshoregas platform in the North Sea and thewest coast of Norway. With a max.water depth of 350 m and a routelength of 67 km, this is the worldslongest XLPE submarine cable.

So far Nexans Norway has installedXLPE submarine cables down to 420 m water depth.

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Oil-filled cables


The first oil-filled cables from Nexans Norway were delivered in

1938. In 1952 we manufactured and installed oil-filled cables for

245 kV. Up to the present time, we have completed an impressive

number of installations for service voltages up to

525 kV, and one objective of our current research is to further

extend this voltage range. Our broad base of experience

comprises installations of every kind, from conventional

underground systems, tunnel installations, vertical shafts more

than 300 m deep without stop joints, to world records in

submarine cable installations in Norway and abroad.

Various types of high voltge ACpower cables are often referred to as“oil-filled cables”. The type manu-factured by Nexans Norway iscommonly described as “self-con-tained low pressure oil-filled cable”with paper dielectric impregnatedwith a low-viscosity oil andincorporating a longitudinal duct topermit oil flow along the cable. Thesuperior electrical qualities of thistype of cable have been proventhrough more than 70 years ofservice experience.

Electrical and mechanical propertieshave been continuously improved bythe introduction of new and bettermaterials and advanced productiontechniques.

Our factory in Halden, by theOslofjord, is equipped with modernand efficient production machinery,ensuring optimum product quality.The factory is capable of producingcables of the largest sizes, both asregards conductor dimension andexternal diameter, and for the highestvoltages. The layout of the factoryallows for highly flexible productionto suit customers´ individualrequirements, and special equipmentis provided for the handling of longand heavy cables. Thus even 525 kVcables can be manufactured injointless lengths of 18-20 km.

Cable design


Cable design

For rated potentials up to 145 kV,both three-core and single-core cablesare used. Above 145 kV, all cablesare of the single-core type.

ConductorThe conductor consists of concentriclayers of helically wound key-stoneshaped copper or aluminium wires.This structure combines excellentmechanical stability with a smoothsurface, which is important in theapplication of the insulation.

InsulationOil-filled cables are insulated withcellulose paper impregnated withmineral or synthetic oil.

Metal sheathThe sheaths that serve to preventwater from penetrating the paperinsulation are metal alloys. Of these,arsenic lead alloy F-3 (0,15 %arsenic, 0.1% tin, 0.1% bismuth,99.65% lead) has proved the mostsuitable, thanks to its favourablemechanical properties (resistance tovibration, low creep, etc.). This alloyhas been used for all high voltage oil-filled cables manufactured by NexansNorway for the last 30 years. Otheralloys may be used at customer´srequest.

ReinforcementOne of the characteristic advantagesof oil-filled cables is that they can bedesigned to suit different cable routesand installation sites. To cater fordifferences in route elevation, suitablemetal reinforcement, normallystainless steel tape, may be appliedover the metal sheath. For cablesdesigned for installation in tunnels orshafts, a combination of longitudinaland transverse reinforcement hasbeen developed.

Outer protectionOuter protection of undergroundcables normally consists of anextruded polyethylene jacket.

Standards and testingOil-filled cables and accessories arenormally designed and tested inaccordance with IEC Publication 141-1: “Tests on oil-filled andgaspressure cables and theiraccessories”. As required, oil-filledcables and accessories can bemanufactured and tested inaccordance with specific nationalstandards or customer requirements.

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The topograhy of Norway is such that cables often have to be laid along routes with large

differences of level, and we have installed 36 - 420 kV cables with static pressures varying from

30 kp/cm2 at one end to 0.2 kp/cm2 at the other end. Systems of this kind have been installed at

several underground power stations in Norway. Our wide experience in the field of oil-filled cables

formed the basis for major export contracts including vertical shaft installations. A few examples

are given here:

TVA, Racoon MountainIn 1976 Nexans Norway installed 14SCOF 161 kV 3250 MCM (1647mm2) cables at Racoon MountainPumped Storage Plant nearChattanooga, for the TennesseeValley Authority. Average route lengthbetween switchyard and powerhouseis 640 m, with a 305 m vertical shaft.

PG&E, Helms Project, CaliforniaIn 1981/82 Nexans Norwayinstalled 10 single-core, oil-filled 230kV 2000 MCM (1013 mm2) cablesfor Pacific Gas & Electric Co at HelmsPumped Storage Plant in the SierraNevadas. The cables connect theswitchyard and the powerhouse andare installed in a 300 m vertical shaft.Average route length is 450 m. Theoperating pressure of the cables is 30bar.

PLN, Jakarta, IndonesiaIn the period 1983 to 1985 NexansNorway installed two double circuitroutes with 150 kV cables in Jakarta,9.3 km and 5.6 km route lengthrespectively, requiring a total of 94.8km of cable. The routes go throughvery congested areas, generally with ahigh water table, putting installationperformance to the test. Installation ofa third double circuit route, approx.12 km long was completed in 1990.

City of OsloIn the late 1960s, the steady rise inOslo´s peak load necessitatedreinforcement of the links betweensubstations around the city. In 1969,2000 m2 aluminium conductor cablesoperating at 300 kV were installed as a part of the main feeder around Oslo. The 9 km installation wasdivided into three separate hydraulicsections and seven crossbondingsections.

SingaporeIn 1984/86 Nexans Norwayinstalled four circuits of 230 kV oil-filled power cables in a tunnelbeneath the busy shipping channel ofEast Jurong Fairway, from Seraya tothe main island of Singapore. Eachcircuit, comprising three cables with2000 mm2 copper conductorstransmits 500 KVA.

The cables were installed withoutjoints. The 2.6 km lengths weretransported in 150-tonnes steelbaskets and pulled into the tunnel bymeans of 60 synchronized pullingmachines along cable ducts cast inthe tunnel floor. To perform thisexacting task, Nexans Norwayemployed a technique speciallydeveloped for projects of this kind.


The Vancouver Project - the highestvoltage and capacityFrom 1982 to 1984, 234 kilometersof 525 kV AC oil-filled submarinecable were installed betweenVancouver Island and mainlandBritish Colombia, Canada. Both thesystem voltage of 525 kV and thetransmission capacity of 1200 MVAfor a single circuit are the highestachieved in submarine cableinstallations ever. Six single-corecables were installed in the cableroute of 30 and 9 kilometers. C/S Skagerrak was used for theproject, after having been rebuilt forworld-wide voyages, adjusted forpassing through the Panama canaland equipped with dynamic-positioning equipment.

Nexans Norway participated inproducing 50 percent of the cables,and performing the entire layingoperation.

The Oslofjord, NorwayFrom 1959 to 1980, the NorwegianWater Resourses and Electricity Boardinstalled three high-voltage submarinecable systems manufactured byNexans Norway to strenghten thepower transmission network on bothsides of the Oslo Fjord and the linkbetween the Norwegian and Swedishtransmission grids.

In 1959 and 1960, six 300 kVcables were laid across the fjord,transmitting a total of 730 MVA. In1974 and 1975, six 420 kV cableswere installed with the addedtransmission capacity of 1710 MVA.Finally in 1980, another six 420 kVcables (two circuits) with the addedtransmission capacity of 1650 MVAwere installed. The route length is sixby 17 kilometers.

Kafue Gorge, ZambiaIn 1989, Nexans Norwayparticipated in the restoration of thecable links at the Kafue Gorge PowerStation, Zambia´s principal source ofpower supply.

The urgency of this assignment led toa decision to transport the 33-tonnescable drums by air. One of theworld´s largest aircraft, the Antonov124, was chartered to lift the 345 kVoil-filled cables from Norway toLusaka airport. This was probably thefirst transport of its kind in the historyof high voltage cable installation.

With responsibility for the second andthird restoration stages, eachcomprising 300 MW transmissionlinks operating at 345 kV, NexansNorway has confirmed its capabilitiesin serving customers at distantlocations and under tropical siteconditions.

Bergenshalvøens KommunaleKraftselskapIn 1995 Nexans Norway supplied300 kV LPOF cables for a total routelength of 15 km for one of the largestNorwegian power utilities. Due to thecrossing of an environmentally sensitivearea an underground cable systemwas chosen instead of overhead lines.

Saudi AramcoIn 1996 Nexans Norway suppliedtwo circuits 230 kV oil-filled cableswith joints and outdoor sealing endsetc. for the Saudi Aramco´s oilrefinery at Ras Tamera. Installation ofthe system took place in cooperationwith local sub-contractors in 1997.

Aqaba BayIn 1997 Nexans Norway suppliedand installed a total of 53 km of 420kV oil-filled cables across the AqabaBay between Egypt and Jordan. Thecrossing has a max water depth of840 m which is a world record forLPOF submarine cables.

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Development for future needs


It is Nexans Norway´s philosophy to focus on customers

needs which lie ahead. Development of products and services

is an inseparable part of the company´s goals and

objectives, as well as a part of its daily work.Beside testing our own products, we offerdomestic and foreign customers facilitiesfor the testing of virtually any type ofcomponent for power transmissionsystems.

High-voltage laboratory

New goals have led to the investment inan advanced high-voltage laboratory atthe company´s Halden plant. This newlaboratory - unique in its size and level oftechnology - is equipped with the latestappliances for the electrical testing ofhigh-voltage components in accordancewith international standards for ratedvoltages up to 765 kV AC and 800 kV DC. Flexible use of floor space isensured by equipment being moved withthe help of air cushions.

The laboratory plays a key role inmaking the Halden plant an importantcenter in the field of high-voltagetechnology.

Research and development


Materials research and development center

This center brings together thedisciplines of metallurgy, instrumentaland chemical analysis as well as theelectro-technical testing of materials,models and polymeric technology.

Besides serving the high-voltage cableproduction in Halden, the center actsas a service unit for all divisions inNexans Norway and is acoordinating link to other cable plantswithin Alcatel Cable as regardsspecial materials analysis.

As a part of the competence centerfor submarine and offshore cablesand umbilicals within the cable group,the center is also responsible forresearch and development within

these product ranges. It is continuouslyinvolved in the study of the electricaland mechanical properties ofmaterials used in special cablesproduced today, as well as for futureproducts.

The center operates four different units:

- Chemical laboratory- Electro-technical laboratory- Materials- and extrusion technical

laboratory- Metallurgical laboratory

Mechanical tensile, bending andtorsion testing is performed on full-scale prototype cable samples in atest plant which simulates laying andservice conditions. Tension is appliedfrom a hydraulic piston to a maximumof 150 tonnes, and the cable is bentaround different sheaves - with

diameters of 1.5 to 10 meters - inorder to simulate the stress inducedaround the laying wheel of the cable-laying vessel.

These advanced laboratories form thebasis for Nexans Norway´sengineering research and productdevelopment and offer power utilitiesand the offshore industry the top-notchtesting facilities needed during allstages of a project.

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For all cable installations, we offer purpose-designed

accessories, manufactured and tested in accordance with

the same international standards as the cable itself,

in most cases IEC standards.

Accessories

We supply purpose-designedaccessories for each particular cablesystem. All our accessories aremanufactured and tested in accor-dance with international recommen-dations (mainly IEC). As essentialcomponents of transmission systems,their quality is of the utmost impor-tance.

Joints and terminations for oil-filledcables are type-tested for systemvoltages up to 525 kV, for XLPEcables up to 420 kV. We supplytransition joints for the connection ofoil-filled cables to XLPE types, andsystems for cross-bonding of sheaths.Our range also includes oil-immersedsealing ends and connections to SF6

insulated busbar systems up to 420 kV.

For detailed information about ourrange of cable accessories, seeseparate brochures dealing withaccessories for oil-filled and XLPEinsulated cables.

Cable accessories andinstallation services


For oil-filled cable systems, NexansNorway designs pressure systems forrelevant site conditions includingnecessary stop joints, oil pressuretanks or pumping plants, oil-feeding systems and relevant alarm and monitoring equipment.

Based on extensive experience withthe installation and maintenance ofoil-filled power cable systems, NexansNorway has recently designed andput into operation a number ofmodular pumping plants used tomaintain oil pressure in oil-filledcables.

These simplified-design plants haveseparate modules for each cable, withmain pressure modules used as a back-up system. A programmablelogic controller (PLC) unit is used forcontrol functions during operatingconditions and should an emergencysituation arise, it alarms and prints tothe nearest manned control center.

It has been a design criteria to easesupervision and reduce maintenanceof the pumping plant, thus increasingthe reliability of the cable system andminimising outage time. Experiencewith the company´s new pumpingplant has already proven outstandingperformance and has lead to repeatorders from our Norwegian customersand the first installations abroad.

Installation capability

The installation of oil-filled or XLPEpower cables requires a staff ofexperienced engineers and teams ofqualified jointers with specialisedtools and equipment for the job.

Our installation departmentundertakes cable laying andprotection, complete electricalinstallation and commissioning inaccordance with customers´requirements.

Our engineers and jointers haveextensive experience from a widevariety of installations - underground,tunnel and submarine - in Norwayand worldwide, in conditions andclimates of every kind. For detailedinformation, see our reference listsand separate brochure on submarinecable installations.

We have developed special tools,equipment and techniques for

- handling of exceptionally long cables in underground and tunnel installations.

- handling of exceptionally long length pulling ashore operations.

- handling and installation of long cables in vertical shafts, i.e. with very high pressures at the lower end.

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The Namsos Plant – Low- andmedium voltage cables

At this plant in central Norway,Nexans Norway employs the verylatest in manufacturing techniques forlow and medium-voltage powercables. The production range coversa standard range of installationcables up to 1 kV and power cablesfor 12, 24, and 36 kV.

The plant is unique in its operatingefficiency and flexibility. The granulated-plastic raw materialsare transported in pipelines fromcentral storage tanks to extruders. The entire production run is high-speed, while the production line iseasily adjustable. In addition, aninternal computer-operated system ofAutomatically Guided Vehicles(AGVs) guarantees a smooth andefficient transport flow.

Nexans Norway is a technologically advanced company

operating four complete cable factories, all fully automated and

able to meet nearly every power and telecommunication cable

requirement. In addition to its main Halden plant, the company

operates the three following plants.

A full range cable supplier


The Rognan Plant –Communication cables

The development and manufacturingof communication cables takes placeat the Rognan plant, north of the Polar Circle.

The product range covers conventionalcopper cables and fibre optic cables;however, more and more of the activity is related to special telecomcables basically used in the offshoreindustry or in submarine telecomsystems.

The main products and areas ofapplications are fibre optic submarinecables for repeaterless system (>300km), electrical umbilical cables oropto/electrical umbilicals, elements forcomposite structures like power + fibreor steel tubes + fibre + copper,dynamic umbilicals for operation ofRemotely Operated Vehicles (ROV`s),seismic cables, special telecomtopside cables (fire resistant and mudresistant).

Expansion, investment in new andefficient production equipment, strictquality control and productdevelopment have been significantfactors in the plant becoming anefficient manufacturer able to adapt tocustomer requirements.

Nexans Norway is today one of theworld leaders in the field ofrepeaterless submarine fiber-opticcables with accumulated supplies ofsome 5.000 km of cable.

In addition to supply of cables thedivision undertakes engineering tasksrelated to accessories(joints/terminations/special tooling)required for installation andmaintenance purposes. Also,extensive test facilities are availablein-house to ensure proper qualificationof cable designs.

The Langhus Plant – Low voltagecables and heating systems

In 1992, a new manufacturing plantand central warehouse wasestablished in Langhus, outside Oslo.This plant´s product range coversinstallation cables in the 1 kV range,as well as heating cables - comprisingmore than 450 different types ofcables altogether. Nexans Norway isthe market leader for these productsin Norway, and exports them on aworld-wide basis as well.

One special range of product madeat the plant is halogen-free safetycables for industrial and domestic useonshore. During a fire, these cablesare virtually gas-free and smokeless,making escape routes safer andpreventing corrosion in expensiveequipment.

New technology and demands haveled to the creation of a uniqueenvironment for ongoing productdevelopment at the plant. Machineryand facilities have been erected forefficient and automated production,which has been carefully adapted tovarying market requirements.

The Langhus Plant is also the logisticcenter of Nexans Norway. Thecentral warehouse is designed toserve our customers with flexible andefficient distribution of more than1,000 different products.

It compromises a computer controlledhigh bay storage facility, shelf storagefor cables of smaller diameters, and acovered outdoor shelf storage areafor the larger types of cables.

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5374 High Voltage Cables