Guide to use for 52
Contents
1. CORRECTION FACTORS FOR DIFFERENT INSTALLATION DEPTHS Installation depth metres 0 50 0 70 0 71 0 90 0 91 1 10 1 111 1 30 1 31 1 50 Correction factor 1 05 1 02 1 00 0 97 0 95 CORRECTION FACTORS FOR THE DIFFERENT SOIL HEAT RESISTIVITIES Soil heat resistivity K m W 0 7 1 0 1 2 1 5 2 0 2 5 3 0 Correction factor 1 10 1 00 0 92 0 85 0 75 0 69 0 63 EXAMPLES OF DIFFERENT SOIL MATERIAL HEAT RESISTIVITIES Dry sand moisture content 0 K m W 3 0 Dry gravel and clay K m W 1 5 Medium dry gravel and sand moisture content K m W 1 2 10 Medium dry and damp gravel K m W 1 0 Damp clay and sand moisture content 25 K m W 0 7 CORRECTION FACTORS FOR DIFFERENT SOIL TEMPERATURES The conductor Soil temperature temperature 5 C OT 5 10 C 15 C 20 C 25 30 C 35C 40 C 45 90 1 13 1 10 1 06 1 03 1 00 0 96 0 93 0 89 0 86 0 82 0 77 80 C 1 14 1 11 1 07 1 04 1 00 0 96 0 92 0 88 0 83 0 78 0 73 70 1 17 1 13 1 09 1 04 1 00 0 95 0 90 0 85 0 80 0 73 0 67 65 1 18 1 14 1 10 1 05 1 00 0 95 0 89 0 84 0 77 0 71 0 63 REKA Cables LTD 2010 10 01 Rights for changes reserved GtU HV52145a20101001a en HANDLING AND OPERATING 22 24 INSTRUCTIONS C A BLE HV Power Cables 52 145 kV R amp D Technical cu2. DRYREX High Voltage Cables 52 145 kV Handling and Operating Instructions REKA C A BL E S HANDLING AND OPERATING 1 24 INSTRUCTIONS C A BLE HV Power Cables 52 145 kV R amp D Technical customer service 01 10 2010 HANDLING AND OPERATING INSTRUCTIONS DRYREX High voltage cables 52 145 kV Contents SCOPE Of applicatlOn i ios0a0sinn sana ia nn aka mana ne aak ste E E RON KMAM N AKU MUN KASTNN 3 General is sisismusse sanan elamaa visat en ee EAEE NE en Ceo ee 3 Professional skills tools and working practices ccuuuosssssssssse sanna naa an naa a Kaanaan Kaanaan nnen aa annan aan Kaanaan an 3 Checking the PrOduot va isamaa an massa setik ins en arikartalu daveiikalituyaikavakskouraekatkunakkataettmali skala reaa n aE aiaia 3 High voltage cable technical information soooooossssss on na n na aan naa an nana nannaa nannaa naan aa ana n naa a Kaanaan neen 4 Handing instructions ceesre REAA RAEES EAE ANE va NAHAN RAN NN KANNAN sesdncecenenauedeesdueeesectouereesunue 5 Packaging and how to handle cable druUmS sssssssssrssssrrnssrnnrssrrnnntnnnnntnnnantnnnnntenaannttananenanantnannenananenananenanannnna 5 Gable dr COonditlOmi 2 sa sas nn paunaa errr errr aka kiaeyhnat unuavak kalanmuaikvkar ksalra suuavaukakavamkraukne k iauu marpkurenausikulaelaa 5 Free space with the outermost cable layer ccccooossmsssisee tanaan naa na kaa KKK Kanaan aa naan Kanaan ana na
3. drying out and the strong increase of the soil heat resistivity which slows down heat transfer as well as secondarily when the operational temperature of the conductor is 90 C and presuming that there is no risk of the ground drying out the responsibility of which belongs to the cable user or when one cable group is installed in free flowing surrounding air with the temperature of 25 C and when the cable conductor s operational temperature is 90 C the continuous loading of the cable is applied 100 load factor according to the international standard series IEC 60287 The current carrying capacity values for the cables are theoretical and they are based on the cable structure and dimensions as well as the basic assumptions listed above Calculations assume that the electrical network frequency is 50 Hz It is only possible to determine the more exact calculatory maximum value for the practical loadability if the cable installation environment parameter values are known for the whole route and when they remain stable This kind of accuracy is not usually possible which is why it is advisable to use an appropriate backup tolerance to the maximum current carrying capacity value when selecting the cable size in order to avoid any surprises caused by the overheating of the cable connection or a single location hot spot Temperature monitoring using optical fibre optional feature A specially ordered optical fibr
4. MONE atomi eat ete tn St Maat Emman sari n E d er dy rhered t keilat E E E 14 Symmetrical trefoil installation c coooooossssise i naa a ana a aa naa KaKa Kaa anna a naa naa naa naa Kananen 14 Symmetrical installation in flat formation planar installation uuoousssssee naan naama annan aa naan 15 REKA Cables LTD 2010 10 01 Rights for changes reserved GtU HV52145a20101001a en HANDLING AND OPERATING 2 24 INSTRUCTIONS C ABL E S HV Power Cables 52 145 kV R amp D Technical customer service 01 10 2010 Installation in the SUITOUNdING All ooooooononnmnn an anna aan anna aa anna aan Kaanaan Ka nana a Kanaa aan KK Kanan Kanna aan a nananana 15 Space required for installation ccoooooosssssss nana aa n a a naa naa na a naa Kana naa naa Kaan na aa naan naene 17 Cable trenches sirsie ra anisina TAI TT asc tbe rd eh Telle a e TiN nt 17 J lnts and termina tons ae Rea E E E E 18 Fino Sand er E E T E E E ne ere tern errrr tr 18 Protective pibes Tor Cables ikisine aar ANSER AE E E hakU NAENKASNSN eaMEENT EVE 18 Protecting the cable enda crru atom eer EEEE EEES EEE NE EELV YLEN NEKIN KNN E AERE E 19 Operating InStruCtiONS sssoisssniannasas takin eani nnen a NNN km amaaan a a aNvamaaKA N N KANT N HAUOUAKUTMKAAN MUA K VUNKUANKAANANRVNANK NANA R AHNEUS ii 19 Cable current carrying Capacity cccooooommmmmsemm ennen aa n naa en aa n aa kaa nana Kana aa a naa Kana naa nana nana n
5. Power Cables 52 145 kV R amp D Technical customer service 01 10 2010 sand and there is a mechanical cable guard such as a protective plate or board above the cables There is a warning tape above the cables close to the ground surface Joints and terminations A sufficiently long and wide section must be dug in those parts of the cable trench where cable joint is to be placed to ensure that it is possible to perform preparation and installation work reguired for jointing with all phase conductors A 6 7 metres long and 2 metres wide excavation should be sufficient to continue with the three joints needed for one three phase circuit three single core cables The dimensions should be estimated based on the space needed for the cable size and the joints to be used for installation based on experience EXAMPLE The space needed for jointing with the cable where the joints have been placed in flat formation The space needed for the installation and lifting of cable terminations must be planned taking into account the type of termination and installation technigue in such a way that the terminations can be installed into the cables and lifted and fastened to their place The working space needed for installing both cable joints and terminations must be protected from effects of the weather conditions such as wind dust and rain A tent or a moveable installation hut for example can be used for protection It is necessary t
6. cable power connector s nominal cross sectional area mm by the limit value of the maximum allowed strength N mm which will be explained later Short cable lengths can also be pulled by people in special cases by grabbing and holding the cable by hand from its oversheath In this case the maximum traction is calculated in the same way as when using the pulling stocking When a pulling head or a pulling stocking is used for the installation pulling the reguired cable lengths must be determined in such a way that the cable ends being pulled can be cut by at least 1 metre the section being strained by pulling tension before installing the accessories REKA Cables LTD 2010 10 01 Rights for changes reserved GtU HV52145a20101001a en HANDLING AND OPERATING 11 24 INSTRUCTIONS C A BLE HV Power Cables 52 145 kV R amp D Technical customer service 01 10 2010 Maximum traction with the pulling head When using the pulling head attached directly to the conductor the following maximum tractions are allowed a high voltage cables with aluminium conductors The nominal cross section area A of the Al conductor is maximum 800 mm F A x 70 N mm The nominal cross section area A of the Al conductor is more than 800 mm F A x 50 N mm However the maximum traction with the pulling head must not exceed the value 50000 N b high voltage cables with copper conductors The nominal cross section area A o
7. free from any burrs in order to avoid damaging the cable oversheath during the installation pulling We recommend that REKA Cables LTD 2010 10 01 Rights for changes reserved GtU HV52145a20101001a en HANDLING AND OPERATING 19 24 INSTRUCTIONS C A BLE HV Power Cables 52 145 kV R amp D Technical customer service 01 10 2010 the seams in the cable protection pipes are water proof The seams must be fitted in such a way that the inner surface of the seam is smooth and does not damage the cable oversheath We recommend that each phase conductor single core cable is placed in its own cable protection pipe The pipe s inner diameter must not be smaller than 1 5 times the diameter of a single core cable If the three phase conductors three single core cables in the same three phase circuit are placed in the same sufficiently large cable protection pipe the cables together must not fill more than of the pipe area The cable protection pipes must be clean of any gravel or sand which might have gotten into the pipe Cleaning can be made with a brush which fits the pipe for example Pulling the cable into the cable protection pipes must be monitored in order to prevent the damage to the cable oversheath caused by gravel or loose stones moving along the pipe edge or into the pipe The traction directed to the cable must be kept as small as possible This is why the pipeline should be as straight as possible and the bending rad
8. high voltage cables tolerate the repeated bending during installation up to the lowest handling and installation temperature given in the product s technical information However as fixed installation cables they are not intended for applications where repeated bending takes place during use EXAMPLE The bending radius is the measurement shown in the picture r Repeated bending during installation pulling During the installation pulling and installation handling the bending is allowed up to the minimum following bending radii Single core high voltage cables 20 x D where D the outer diameter of the cable One one off even bending to the final position When the high voltage cable is bent with a one even one off bending to its final position the minimum allowed bending radius level is 70 from the value which was allowed for the cable for the previous repeated bending It is not however allowed to go below the minimum values for the bending radii given in the cable technical information REKA Cables LTD 2010 10 01 Rights for changes reserved GtU HV52145a20101001a en HANDLING AND OPERATING 10 24 INSTRUCTIONS C A BL E HV Power Cables 52 145 kV R amp D Technical customer service 01 10 2010 When working in cold conditions it is also recommended that the cable part to be bent should be allowed to warm up to the minimum temperature of 5 C using a thermal tent for example The heating must never be
9. the magnetic material This relates also to the fastening wires or tapes of identification plates which could be attached to the cable Space reguired for installation When designing the installation and selecting and dimensioning the cable route for the DRYREX high voltage cable the allowed bending radii and the traction strains caused by the cable route must be taken into account together with the installation technigue used in such a way that the limits given to the cable are not exceeded Cable trenches When the cable trench is designed and dug care must be taken to ensure that the installation pulling of the cable to its place is possible using the reguired tools and pulling machines and that the space needed for the filling soil under the cable and to the sides of the cable has been taken into account It must also be made sure that cables are placed in their correct installation formation in the planned installation depth and that there is sufficient space for the filling soil around the cable EXAMPLE Typical arrangement of high voltage cables in the cable trench The installation depth must fulfil the minimum reguirements for high voltage cable installation and correspond with the values used in the design calculations In the above example images cables are surrounded by filling REKA Cables LTD 2010 10 01 Rights for changes reserved GtU HV52145a20101001a en HANDLING AND OPERATING 18 24 INSTRUCTIONS C A BL E HV
10. the user must calculate new values corresponding with the applied installation formations and distances as far as the changes in the distance between cables effect them Asymmetrical trefoil installation leads to uneven loads on the individual phase leads and the values calculated according to the symmetrical trefoil installation are not valid Symmetrical installation in flat formation planar installation The phase leads of the three phase current circuit formed by three single core cables are placed in such a way that the conductors are on the same level and at egual distances from each other REKA Cables LTD declares the electrical values for the planar installation in the installation format where the distance between the single core cables is egual to the outer diameter of a single core cable In this case the relative distance between the conductor axels of adjacent cables eguals two single core cable outer diameters The values given in the product technical information are theoretical guidance values for planning and they are not deemed to be binding EXAMPLE Basic image of symmetrical installation in flat formation We do not recommend a shorter free space than the outer diameter of one cable for planar installation With the symmetric installation in flat formation where the relative distance between conductors is different to the distance given in the technical information the user must calculate new values corresponding with the a
11. voltage cables generally have such large dimensions that it is not possible to coil them and this is why we recommend cable drums as packaging even for smaller sized cables Low storage temperature When cables are stored in lower temperatures than the lowest temperature allowed for handling installation or transportation cables must not be subjected to any kind of mechanical stress such as collisions blows bending and twisting The cable must be allowed to warm up sufficiently before handling or transportation in order not to go below the lowest temperature limits For larger cables the required time for the temperature to normalise can be 24 36 hours Instructions for handling cable drums Cable drums must be stored with the barrel axis in a horizontal position and in such a way that the drum flanges do not touch the cable in another drum High voltage cable drums must not be stacked on top of one another REKA Cables LTD 2010 10 01 Rights for changes reserved GtU HV52145a20101001a en HANDLING AND OPERATING 6 24 INSTRUCTIONS C A BLE HV Power Cables 52 145 kV R amp D Technical customer service 01 10 2010 STORAGE VIEWED FROM ABOVE Transporting the cable drum You must use appropriate transportation eguipment for transporting cable drums The cables must be transported with the barrel axis in a horizo
12. where the current carrying capacity is at its lowest Determining the current carrying capacity is based on the heat which is formed in the cable transferring outwards from the conductor in such a way that the temperature of the cable and its materials does not increase more than what is appropriate REKA Cables LTD 2010 10 01 Rights for changes reserved GtU HV52145a20101001a en HANDLING AND OPERATING 20 24 INSTRUCTIONS C A BLE HV Power Cables 52 145 kV R amp D Technical customer service 01 10 2010 Basic assumptions of the load current values The DRYREX high voltage cable technical product information or technical specifications explain in which basic condition the standard value of the current carrying capacity is calculated typically when three single core cables are installed directly into the ground the soil temperature is 15 C the soil heat resistivity is 1 0 K m W the installation depth is 1 0 metres when the installation formation is a symmetrical trefoil installation with cables touching each other and when the installation formation is a symmetrical installation in flat formation the free space between cables equalling one diameter the cable s metallic screen circuit is closed connected together and earthed at least in both ends of the connection and primarily when the operational temperature of the conductor is 65 C to avoid the risk of the ground
13. 10 10 01 Rights for changes reserved GtU HV52145a20101001a en HANDLING AND OPERATING 12 24 INSTRUCTIONS C A BL E HV Power Cables 52 145 kV R amp D Technical customer service 01 10 2010 CABLE DRUM DRIVER CABLE ROLL straight CABLE WINCH motor driven rollers CABLE ROLLS corner CABLE PULLING MACHINE DUPON EXAMPLE Basic image of a cable pulling arrangement The motion of the cable being unwound from the drum must be monitored and directed to ensure that the cable moves along the correct route The cable drum must turn on its axis as easily as possible to make sure that the cable is subjected to as little pulling strain as possible The cable drum movement must be monitored and if required braked in such a way that if pulling slows down or stops the cable drum does not carry on turning and cause unnecessary or tight bends or loops 3 aT mm LS gt DAA EXAMPLE Basic image of managing the cable drum rotation The friction of the outer surface of the cable oversheath during the installation pulling into cable protection pipes or through feed throughs can be reduced by spreading lubricant on the surface However the lubricant must REKA Cables LTD 2010 10 01 Rights for changes reserved GtU HV52145a20101001a en HANDLING AND OPERATING 13 24 INSTRUCTIONS C A BL E S HV Power Cables 52 145 kV R amp D Technical customer service 01 10 2010 not be harmful t
14. 46 metres The sidewall pressure calculated according to the case a is Pswp 21000 N x 004 m 1 46 m 5753 N which exceeds the limit value 5000 N and therefore is not allowed The distance between the rolls should be made shorter and the amount of rolls in the turn should be increased the traction should be decreased or the turning radius increased Safety during installation pulling The safety of the installation personne during pulling should be noted especially in order to ensure that the cable motion or the movement caused by the release from traction does not cause any harm to the installers During motorised pulling the cable motion must not be touched by hand to try and prevent the movement or in such a way that the person is at risk of being sgueezed or caught When the installation pulling is finished care must be taken to ensure that the cable ends do not remain open and that they are not left at the bottom of the excavation or under water even if protected Installation formation The DRYREX high voltage cables intended for fixed installation can be installed as surface installations surrounded by air for example on cable racks cable channels or similar or dug into the ground according to what the published technical information for the cable mentions about the product applicability The cable installation formations must be planned and realised as symmetrical trefoil installations or as planar installations in flat formati
15. KA Cables LTD 2010 10 01 Rights for changes reserved GtU HV52145a20101001a en HANDLING AND OPERATING 24 24 INSTRUCTIONS C A BLE HV Power Cables 52 145 kV R amp D Technical customer service 01 10 2010 We recommend that the oversheath d c voltage test is performed for each pulling length separately immediately after the cable trench has been prefilled and before the accessories such as cable joints have been installed When performing the oversheath d c voltage test it must be noted that if a conducting surface layer optional feature is used for the cable oversheath to be tested it must be peeled off for a distance of 50 100 mm from both ends of the cable so that there is no test voltage flashover from the oversheath surface to the metallic screen at the cable cutting points The cable ends must also be left raised at least 50 cm from the ground For industrial safety reasons it must be ensured that the cable and its surroundings are free from any people during the voltage test There must be a break of minimum 5 minutes immediately after the test voltage is switched off during which the cable s metallic screen is connected to earth in order to discharge the charge accumulated to the oversheath during d c testing If any damages which have broken the oversheath are found or measured they must be checked and repaired before using the cable system The appropriate repair method used in cable technigue must be selec
16. aan anne 19 Basic assumptions of the load current Values eccosoossmssssee sanna aa naa aa naan annan annan aa Kaanaan nannaa 20 Temperature monitoring using optical fibre optional feature eccouuummsssesm na eka aa na aan n naa aaeen 20 LOACING TACtorS aooscnerssutmnerasa vian ANE Ka A SAN IEE A EN UAE AN MSK EEA USA AN IEE L K I KOSTAnn e KYYATE upee NUKUN NATMANAHEI E 20 Loading factors relating to the ground installations ooooosossssss aan a aa naa aa naa aa naan nannat 21 Correction factors for the surrounding Air lt ooosssssss n a ana a naa Kaanaa anna naa a naa naa naan aa naaaeeen 22 Tests alter installation oes es ene S hat eect taen ae Nivan r eee Sahan ia eie aniksen ete hed velraaiaadsn 23 The voltage test for the insulation ssoooooooiossso aa a aa aa naa a KKKA aa naa aa kaa aa Kaanaa aa naa aa n kaa naan an 23 The oversheath voltage test soosooooooososs naan an aa aa kaa aa naa aa kaa a a naa aa Kaanaa a nannaa naa ana n kana annan 23 Measuring the optical fibre attenuation ccosoosussssssss sen e aa e aa an naa a Kanaan Kanaa aan nana Annaa naan nannen 24 REKA Cables LTD 2010 10 01 Rights for changes reserved GtU HV52145a20101001a en HANDLING AND OPERATING 3 24 INSTRUCTIONS C A BLE HV Power Cables 52 145 kV R amp D Technical customer service 01 10 2010 HANDLING AND OPERATING INSTRUCTIONS DRYREX High voltage cables 52 145 kV Scope
17. e used for measuring the cable temperature can be located to the DRYREX high voltage cable metallic screen and it can be connected to special commercially available monitoring equipment This arrangement enables the monitoring of the cable connection temperature in such a way as not to exceed the maximum allowed temperature for the cable and the controlled loadability matching the maximum allowed temperature can be used It is however advisable to note that when the operational temperature for the cable is increased the losses created in the cable are also increased Therefore selecting the nominal cross sectional area to keep the cable continuously on the maximum load can become uneconomical over a longer period Loading factors Determining the current carrying capacity of a high voltage cable in installation conditions which differ from the basic assumptions listed above and used for calculations can be made using correction factors The current carrying capacity value according to the above mentioned basic assumptions must be multiplied with the loading factors according to the relevant installation conditions parameters see the tables below REKA Cables LTD 2010 10 01 Rights for changes reserved GtU HV52145a20101001a en REKA L E S C A B R amp D Technical customer service HANDLING AND OPERATING INSTRUCTIONS HV Power Cables 52 145 kV 01 10 2010 21 24 Loading factors relating to the ground installations
18. ensure that the strains the cable is subjected to do not exceed the limits set in the technical information When reguired cable installation tools which are intended to ease the cable motion and to reduce strain must be used The cable lengths must be determined sufficient for installation pulling and the installation pulling must be implemented in such a way that the cable ends being pulled can be cut by at least 1 metre the section being strained by pulling tension before the preparation work reguired for installing the accessories There must be a radio or telephone connection between the people performing the installation pulling and those supervising it so that required instructions can be given during the pulling or the pulling can be ordered to stop Managing pulling strains During the installation work the pulling strains the cable is subjected to must be kept as low as possible A freely rotating joint must be used between the pulling wire and the pulling head which allows the cable or the wire to rotate independently During the cable pulling a measuring device a traction meter or a mechanical fuse which breaks due to the limit force force indicator gauge must be used to monitor that the maximum allowed traction for the cable is not exceeded When using mechanical cable pulling the pulling machine user must be connected with the traction monitoring to ensure that the allowed limit values are not exceeded REKA Cables LTD 20
19. f the Cu conductor is maximum 1 200 mm F A x 90 N mm However the maximum traction with the pulling head must not exceed the value 50 000 N When calculating the upper limit for the traction the cross section area of the metallic screen or the metal sheath is not taken into account Example When using a pulling head the theoretical traction value for the high voltage cable HXCHBMK W 110 kV 1x630 70 would be F 630 mm x 90 N mm 56700 N but the maximum is determined by the upper limit 50000 N Maximum traction with the pulling stocking When using a contracting pulling stocking attached to the top of the cable oversheath the following maximum tractions are allowed c high voltage cables with aluminium conductors when the A of the Al conductor is lt 1200 mm F Ax 15 N mm d high voltage cables with copper conductors when the A of the Cu conductor is lt 1200 mm F A x 20 N mm However the maximum traction with a pulling stocking must not exceed the value 8500 N Example The maximum allowed traction for the high voltage cable AHXCHBMK W 110 kV 1x500 35 when using a pulling stocking is F 500 mm x 15 N mm 7500 N and similarly for the high voltage cable HXCHBMK 132 kV 1x1200 95 maximum 8500 N because the limit 8500 N must not be exceeded Implementing installation pulling Only eguipment which is sufficiently strong and safe can be used for the cable installation pulling Care must also be taken to
20. heath thickness measured for the cable during manufacturing These are presented in the testing protocols of the production batch It is the responsibility of the customer who ordered the cable to inform the persons responsible for the cable installation and use about the product specific technical information and the limits regarding the handling and use In these handling and operating instructions the product specific limits are primary values in comparison to the general values REKA Cables LTD 2010 10 01 Rights for changes reserved GtU HV52145a20101001a en HANDLING AND OPERATING 5 24 INSTRUCTIONS C A BLE HV Power Cables 52 145 kV R amp D Technical customer service 01 10 2010 Handling instructions Care must be taken when handling the products and the correct rotation direction of the cable drums must also be taken into account The industrial safety hazards which can be caused by the large sizes and bulks of the packaging mostly the cable drums must also be taken into account In addition to the correct lifting and transfer methods it is required that the lifting mechanisms and equipment are sufficiently strong to carry the overall volume and that during transportation cable drums are fastened against any unexpected movement of the load General instructions about handling cable drums can be found in the REKA Cables LTD Drum Handling Guide see http www reka fi For high voltage cables the large dimensions and ty
21. ing voltage test for insulation can be discharged by earthing both the connector and the metallic screen or by connecting them to each other for at least one hour The oversheath voltage test If there is a special reason to suspect that the cable oversheath might have been damaged during the installation but it is not possible to pinpoint the damage visually the cable oversheath can be tested with the direct voltage test d c voltage test using the method according to the standard IEC 60840 2004 section 15 1 However reliable oversheath d c voltage testing reguires either exceptionally good conductivity from the soil into which the cable is installed or alternatively connectivity from the surface of the cable oversheath using for example a specially made semiconducting surface layer The value of the d c test voltage for the cable oversheath d c voltage test is determined based on the nominal value of the sheath thickness 4 kV per millimetre of thickness However the upper limit for the d c test voltage is maximum 10 kV d c For the oversheath d c voltage test the test voltage is connected between the cable metallic screen and the soil surrounding the cable for 1 minute There must not be any breakdown during testing In order to perform the oversheath d c voltage test all metallic layers of the metallic screen such as copper wires and any metallic laminate acting as the moisture barrier must be connected to each other RE
22. ius in the necessary turns as big as possible Care must be taken not to exceed the allowed sidewall pressure Pswp In order to reduce the friction between the cable and the cable protection pipe and to reduce installation traction it is not allowed to use such lubricant which damages the cable oversheath material either immediately or after a period of time We recommend only water soluble lubricants specially manufactured for cable pulling These lubricants are commercially available It is forbidden to use materials which damage the oversheath plastic as well as materials which are classed as being harmful to its users or the environment Protecting the cable ends REKA Cables LTD has protected the open ends of the cables against moisture with special protective caps When the cable is installed and cut as required the open ends unless they will be worked with immediately must be protected in such a way that moisture or water cannot enter the cable structure and cause corrosion Sufficient protection is achieved by closing both open ends of the cable with a plastic shrinkable cap with heat melting glue on the inner surface The protective cap is shrunk tightly to the open end of the cable During heat shrinking care must be taken no to heat the cable s oversheath plastic too much When using a gas flame additional care must be taken not to cause a fire risk The protective caps on the cable ends may get damaged during transportation or sto
23. material similar to the surrounding soil with the same heat resistivity there is no need to apply the correction factors in this table separately from the table above for adjacent three phase groups Correction factors for the surrounding air CORRECTION FACTORS FOR DIFFERENT TEMPERATURES OF THE SURROUNDING AIR The Surrounding air temperature conductor temperature 10 C 15 C 20C 25 C 30C 385 40 C 45 C 50 C 55 C 90 C 1 12 1 08 1 04 1 00 0 95 0 90 0 85 0 80 0 74 0 68 80 C 1 14 1 09 1 05 1 00 0 95 0 89 0 84 0 77 0 69 0 61 70 C 1 18 1 12 1 06 1 00 0 93 0 86 0 79 0 71 0 62 0 52 65 C 1 20 1 14 1 07 1 00 0 93 0 85 0 77 0 68 0 57 0 45 REKA Cables LTD 2010 10 01 Rights for changes reserved GtU HV52145a20101001a en HANDLING AND OPERATING 23 24 INSTRUCTIONS C A BLE HV Power Cables 52 145 kV R amp D Technical customer service 01 10 2010 Tests after installation The testing after installation with voltage tests means testing both the cable and its accessories together REKA Cables LTD has tested all supplied cable lengths with high voltage testing in the factory If the user wishes for special reasons to test the installed cable and the assembly of the accessories connected to it it can be done for the cable as mentioned hereafter The voltage test for the insulation The condition of the cable insulation was
24. ng radius s ssasisinr rensei aaan naan naa a i KRAANA KKK KaKa KRAANA ARANAN ANR ERNA 9 Repeated bending during installation pulling ssssessrsssssrsssnsnsssrnnansnnnansnananannnansnnnnnnennnernnnnnnennnennnnannnnnannna 9 One one off even bending to the final pOsitiON oooooosssssss n na n aa aa enaa enaa naan Ka a Kaanaan 9 Wijen rewinding thecCaDlena iissss0a otsi mate Tessa chads sesseucethaenedsseaesuelecacdetssdasduceataeteneseareuesaneeastesvavies 10 Madmumtkaotions alloweaii ssis sssia sits ravaa m corer ETa Ku hcdeagh TUKIN KIN TTR 10 Maximum traction with the pulling head eosoususssssss n ana aa naa an naa a Kaanaa Kaanaa naan aa Kaanaan n naenen 11 Maximum traction with the pulling StoCking ueossssssssee a an a ae nana annan a naan a KKK aa Anaan nannat 11 lmplementing installation pulina aste cect msn cece tee ieetalae eee lel ee Lena aa nana a ntaae i Kanaa ia annan a majaan e Olds aave A 11 Managinglpulling strains ossis msn mist masi hac ee buena saben dee oth ba AEREE AARNA ain erster ka evien 11 Gable rollskand drivers ticino saa nkemn ti eaves etc tarte Ne r ys Tete TK E iv a AOSA A Ea AO aaa ar VAIHETTA Ar TTA A Se 13 Maximum allowed side wall preSSUfC sooouossssssss een an aa a naa nannaa annan Annaa annan aa annan anne aenen 13 Safety duriing install tion Pullin s t sssssn antaisi ravata varmaa eas aaka aa KNNNT AKUN PKA UTULA AN NANHN M NKUUTU ANK EK KNKKK KANA 14 Ista lATIOM
25. nna nanna nanna 5 How to fix the cable end to the ArUM cccooooooooeseieie anna an aa aa Kaan a Kaanaa naan a kaa Aaa Kana Kankaan aa nn aaaaeen 5 Cable COlS E ceteice nes a Re aa nm t beads tah Anes heeded th cae ads KIT ead ka kan N m v aius kk u yk va m ae Ele kUUKN ea k ahmii 5 Low storage temperature sssooooooosieseeiitet aate ta maana nannaa KKK Kaa aan Kanaa aan Ka KaKa Kaanaan Kanaa aa Kaa Kanan KK Kanaa aa nananana 5 Instructions for handling cable ArUMS ccccooossssssse sanaa n aa na naan anna aaa a KKKA a Kaanaa Kaanaa ANAREN 5 Tir nsporting the cable drum s 2ossssesestasta susan utan d sa va sakav kaa dumo varaka vaarana E alue kaa vaimeana akan dNol sen keu vke 6 Loading and unloading cable ArUMS ocsoosussssssse ekaa ekaa an aa a naan a naan a kana a Kaan ankan EEEE 6 Rolling the cable Arumn aiviunatuana mo ipest nama easa asein Teresa EN setae eg Ee i daa NEIN rr Nye L e aN ee eb ve TUE TVA NEn o 7 Unwinding and rewinding the cable from and onto the ArUM ccccoooossesesee eie ekaan a nana a naan aa Kaanaan 7 lowest allowed tem peratures issssus issasestksvismmmessta ks aude RETRE sheds Gets SRANN URENA RETETA mA TEK KUUN T NAIM ENNN TARU AN TAKKU KNN 8 Durg rans porion aaa a ma a TES e E seh aa Ea Ea rA hel R ATA TT unie RE due abana So i 8 When Randlingi and installing eea eeraneenaareasee m kat t aaea naria R ai EAA NENA EAER AEE TAATA AA g The minimum allowed bendi
26. ntal position Drums must be fastened in such a way that they do not move during transportation KEEPING THE DRUM IN AN UPRIGHT NOT LIKE THIS POSITION PLACE WEDGES TO THE FLANGE BASE Loading and unloading cable drums Cable drums are loaded and unloaded using appropriate lifting devices and methods Do not drop the drum THE DRUM CAN BE LIFTED EITHER WITH A FORK LIFT OR A CRANE REKA Cables LTD 2010 10 01 Rights for changes reserved GtU HV52145a20101001a en HANDLING AND OPERATING 7 24 INSTRUCTIONS C A BLE HV Power Cables 52 145 kV R amp D Technical customer service 01 10 2010 Rolling the cable drum We recommend that the cable drums are moved by lifting them Moving them by rolling is allowed only for short distances on a level and solid surface The rolling direction must be selected so that the cable on the drum does not become loose or start to unwind Pay special attention to stop drum flanges sinking to the ground and the cable getting sgueezed between the barrel and the ground When moving the drums by hand even for short distances you must also make sure that personal safety is not at risk DRUM ROLLING DIRECTION Unwinding and rewinding the cable from and onto the drum The cable is unwound from the drum with the axis in horizontal position by pulling the cable from the drum as shown in the picture below The drum must rotate easily so that the pulling strain to the cable will remain as small as p
27. o organise the removal of water from the cable joints installation pit or excavated space for example by pumping in order to prevent the cable and its accessories from getting wet during installation During the cold time of the year the protective tent or hut must be heated in order to enable the installation of accessories to the cable The type specific instructions from the manufacturer may reguire that the terminations are installed into the cable in upright position in which case necessary scaffolding must be used Necessary weather proofing against wind dust and rain must be organised during the terminal installation work Filling sand At least approximately 20 cm thick layer of fine sand must be used on the bottom of the cable trench under the cables and at least approximately 20 cm thick top layer of fine sand on the top of the cables The material must be of even guality The soil dug out from the same cable trench must not be used for the bottom and top soil layers surrounding the cables Protective pipes for cables The mechanical protection of cables in underground installations can be improved by installing them inside special sufficiently strong cable protection pipes which can for example be made of polyethylene PE Other suitable non magnetic materials for the pipes include ceramics and cement for instance The inner surface of the cable protection pipes must be smooth and the inside edges of the pipe ends must be round and
28. o the oversheath material or the user We recommend only water soluble lubricants specially manufactured for cable pulling Cable rolls and drivers The friction caused by chafing during installation pulling must be reduced by placing the cable guiding rolls on the straight section at 2 4 metre intervals and in bends so as not to go below the cable s minimum bending radius At the turning point there must be enough rolls to both support and guide the cable At the same time it must be ensured that the cable traction in turning points does not cause the inner side of the cable to get pressed too hard against the rolls EXAMPLE Cable roll left for straight sections right for corner sections It is advisable to plan the rolls and their location as well as the personnel for guiding the cable movements in advance The free rotation of the rolls must be checked once they are in place Other drivers or supports must have rounded edges and their surfaces must ensure that the friction between the oversheath and the driver remains as small as possible EXAMPLE A single cable roll and the cable s movement over it on a straight section Maximum allowed side wall pressure The curves and turns of the installation pulling cause side wall pressure to the cable when the cable is pressed against the surface of the cable s protective pipe or the rolls and drivers located on the turning point The size of the strain of the side wall pressure depends
29. of application These handling and operating instructions relate to aluminium and copper power cables of rated voltages 52 kV lt Un lt 145 kV manufactured by REKA Cables LTD which are intended for fixed installation in the high voltage network In addition to these handling and operation instructions those product specific instructions and limits which REKA Cables LTD has published for the high voltage cable product as technical information or as product specific specifications must be complied with These handling and operation instructions do not present general technical basic reguirements for the cable systems nor country specific authority regulations which must be taken into account when planning high voltage cable connections or when putting them to practice These handling and operation instructions do not give instructions for dimensioning the cable system nor specifying the electricity network These issues are the planner s responsibility The earthing arrangements for the cable system at least from both ends solid bonding from one end only single point bonding or alternating cross bonding must be taken into account at the system planning stage and it will have an effect on the high voltage cable operating characteristics as well as on the selection and installation of the accessories Other issues which are the responsibility of the planner are the solutions regarding the installation format fixing and support structure
30. of the cables and their appropriate selection the possible use of thermally stable filling soil use of warning tapes and warning coverings protection of cables with gouges or protective plates etc These handling and operation instructions do not include the detailed installation instructions and dimensions of the cable joints and terminations the manufacturer of the selected cable accessory must supply them according to the type of an accessory These handling and operation instructions do not include submarine cables nor installation or use of these products in other such special conditions nor the aerial installation of cables on poles or other similar solutions These handling and operation instructions do not release the customer installer user from their responsibilities General Professional skills tools and working practices Only professional and professionally trained persons are allowed to perform the cable installation work Only tools and eguipment suitable for the working practice and intended for cable installation can be used in cable installation work The applicable working practices must be professional intended for high voltage cables installation technigue and they must follow the good installation practice The limits given to the cable in guestion as well as these operating instructions must be taken into account when handling and installing cables These handling and operating instructions do not repeat those indus
31. on When installing cables care must be taken to ensure that the planned installation formation and its symmetry remains according to the plan for the whole length even during the filling of the cable trench and afterwards With the trefoil installation where the cables are meant to touch each other the installation formation can be retained more easily by using a suitable bonding tape at regular intervals to keep the cables in place Symmetrical trefoil installation The phase leads of the three phase current circuit formed by the three single core cables are placed in such a way that the distance of one conductor centre conductor axis to another is egual REKA Cables LTD declares the electrical values for trefoil installation in the installation format where the single core cables touch each other In this case the relative distance between conductor axes is a value which is egual to the outer diameter of a single core cable The values given in the product technical information are theoretical guidance values for planning and they are not deemed to be binding REKA Cables LTD 2010 10 01 Rights for changes reserved GtU HV52145a20101001a en HANDLING AND OPERATING 15 24 INSTRUCTIONS C A BLE HV Power Cables 52 145 kV R amp D Technical customer service 01 10 2010 EXAMPLE Basic image of symmetrical trefoil installations With the symmetric trefoil installation where the relative distance between conductors is larger
32. on the turning radius and the size of the traction the cable is REKA Cables LTD 2010 10 01 Rights for changes reserved GtU HV52145a20101001a en HANDLING AND OPERATING 14 24 INSTRUCTIONS C A BLE HV Power Cables 52 145 kV R amp D Technical customer service 01 10 2010 subjected to after the turn The side wall pressure must be kept as small as possible by keeping the installation route as straight as possible the radius of turning points as big as possible and the size of the change of direction in the turning point as small as possible The side wall pressure is calculated case specifically a in the turns and bends against the cable rolls using the formula Pswp Txd r lt 5000 N b in the turns inside the plastic protective pipes or against the guiding grooves using the formula Pswp T r lt 22 000 N where Pswp sidewall pressure as the turning point radius N m T cable s traction after the turn N d distance between the cable rolls m r the radius of the turn or the bend m The limit values of the sidewall pressure may restrict the allowed traction for the cable and they must be taken into account Example The minimum allowed bending radius for the high voltage cable AHXCHBMK W 110 kV 1x300 70 during installation pulling is 1 46 metres Is it possible to pull the cable with a maximum traction of 21000 N through four cable rolls which are 0 4 metres apart with a minimum bending radius of 1
33. ossible The drum movement must not be slowed down except when preventing an extra loop when the cable pulling stops m H m N v v m UNWIND THE CABLE FROM THE DRUM LIKE THIS NEVER LIKE THIS Separating a cable length from one drum to another cable drum or transferring a cable from one drum to another is made by rewinding as shown in the picture below The size of the drum to which the cable is transferred must be selected without going below the smallest allowed bending radius When using wooden drums they must be checked on the inside for any possible raised nails or screws before rewinding to avoid any possible damage to the cable oversheath REKA Cables LTD 2010 10 01 Rights for changes reserved GtU HV52145a20101001a en HANDLING AND OPERATING 8 24 INSTRUCTIONS C A BLE HV Power Cables 52 145 kV R amp D Technical customer service 01 10 2010 RECOMMENDED NOT RECOMMENDED When rewinding the cable the cable temperature must not be any lower than the lowest handling and installation temperature allowed The cable must first be allowed to warm up to the appropriate handling temperature Lowest allowed temperatures The structural materials used for the cable such as the compounds for insulation and oversheath plastic will endure the extra stress caused by movement during transportation or normal handling during installation up to the certain lowest temperatures These temperature limit
34. performed by directing hot or spot like heating or a gas flame to the cable or to a cable part When rewinding the cable When rewinding the cable lengths after unpacking from the factory packaging on the cable coil or other cable drums the following minimum bending radii are allowed and they must be taken into account when forming the cable coil diameter or when selecting a suitable cable drum for rewinding Single core high voltage cables 15 x D where D the outer diameter of the cable When reguired the diameter of the selected cable drum must be increased with sufficiently thick boarding for example in such a way that the bending radius of the lowest cable tier is not too small When attaching the boarding it must be ensured that there are no raised nails or screws which could penetrate the cable oversheath Maximum tractions allowed When the high voltage cable is installed the fixing tools allowed are the pulling head pulling eye attached directly on the metal conductor or the pulling stocking pulling grip which shrinks due to the traction and which is placed on top of the cable oversheath The traction limits mentioned in these operating instructions are for high voltage cables They must not be applied to medium voltage cables EXAMPLE Pulling head and a basic image of connecting the pulling head to the pulling cable The value of the maximum allowed traction N for the fixing tool is calculated by multiplying the
35. pically large bulks of the cables and their delivery drums must be especially taken into account Packaging and how to handle cable drums Cable drum condition Take care not to damage the cable drum when handling it It is advisable to check the exterior condition of cable drum regularly during storage and when starting the installation of the cable from the drum The possible protective boards used for extra protection for the cable drum must not be removed until the cable is transported to the installation position ready to be installed Free space with the outermost cable layer With a full drum the distance between the outermost cable layer and the earth or the protective boards used as extra protection must be sufficient We recommend free space of one cable diameter or at least 5cm between the surface of outermost cable layer and the protective boarding How to fix the cable end to the drum Cable ends must be attached firmly to the drum during transportation and storage The fixing of the inner end of the cable threaded out from the flange has an effect to the free width reguired when handling the drums Cable coils Shorter lengths of small diameter cables can be transported and stored as coils in horizontal position Cable coils must be protected from mechanical stress blows and direct sunlight The cable coil diameter must not be smaller than the smallest bending radius given for its handling and installation allows However high
36. pplied installation formations and distances as far as the changes in the distance between cables effect them Asymmetrical planar installation leads to uneven loads on the phase leads and the values calculated according to the symmetrical installation in flat formation are not valid Installation in the surrounding air The cables which are installed on cable racks for example so that they are surrounded by air must be protected from direct sunlight unless the heat effect caused by this has been especially taken into account when determining the current carrying capacity of the cable connection and the cable selected for installation REKA Cables LTD 2010 10 01 Rights for changes reserved GtU HV52145a20101001a en HANDLING AND OPERATING 16 24 INSTRUCTIONS C A BL E HV Power Cables 52 145 kV R amp D Technical customer service 01 10 2010 ro EN NEN Pg RON Soak an ee X i A NOR a qu amp K s as ty r a j E K pant JA EN je 35 x zi rg i EN ks k JA Ay i ae sa ki 13 yey Ja J EA ETT el TY Ko KAAJA TSn eR ts a gaya Pena sect EXAMPLE Basic image of high voltage cable installation on cable racks The cables must be attached at 0 5 1 5 metre intervals in order to retain the installation formation The clamps must be designed for cable installation and they must be suitable for the diameter of the selected cable If the cable installation is expected to hold out agains
37. rage If there is any doubt or if it is seen that the protection is damaged or become loose it must be checked and replaced when necessary It is recommended that the cable end protection is inspected visually at suitable intervals during long term storage Operating instructions Cable current carrying capacity REKA Cables LTD determines the standard values of the DRYREX high voltage cables current carrying capacity according to the basic principles of the international standard series IEC 60287 The theoretical standard value is explained in the cable technical product information for one or possibly several typically used installation situations These are example situations which are intended to describe the cable s performance in the most usual cases The standard value for cable current carrying capacity is always bound to those basic conditions the starting values of the installation environment which were used for calculation and which were declared in connection with the load current value The exact actual values if they are needed after the installation can only be defined by measuring If the planned installation conditions differ from the basic information given for the standard values applicable correction factors must be used or the load current value must be calculated under basic conditions which match the installation conditions The amount of loadability for the cable connection is determined by the location or section
38. retardant special cables with LSF Low Smoke and Fume oversheaths 25 C If the product specific technical information stipulate higher warmer temperature limits than those given above they must be complied with REKA Cables LTD 2010 10 01 Rights for changes reserved GtU HV52145a20101001a en HANDLING AND OPERATING 9 24 INSTRUCTIONS C A BLE HV Power Cables 52 145 kV R amp D Technical customer service 01 10 2010 When handling and installing During handling and installation work cables are subjected to bending tractions and abrasion of the oversheath as well as other similar normal strains This is why the cable temperature as a whole or where a part of the cable is subjected to handling and the mechanical strain caused by handling the temperature must not be below the following temperature limits Cables with polyvinyl chloride PVC oversheaths 15 Cables with polyethylene PE oversheaths 20 C Flame retardant cables with special LSF Low Smoke and Fume oversheaths 15 C If the product specific technical information stipulate higher warmer temperature limits than those given above they must be complied with The minimum allowed bending radius The bending during the cable handling and installation cause tensile stress on the outer edge of the bending and compression stress on the inner edge of the bending to the cable components As fixed installation cables the DRYREX
39. s are specific to different materials and this is why the lowest allowed temperatures are specified in the technical information for each cable Care must be taken to ensure that the temperature of the cable being handled is not lower than the lowest allowed temperature limits in order to avoid damage to the cable structure If the surrounding temperature is lower than the allowed handling temperature the cable must first be warmed up by storing it inside in a warm room or in a thermal tent for example It s advisable to note that a full drum of high voltage cable can take as long as 24 36 hours to reach the handling temperature When the cable is handled in lower temperatures its plastic oversheath materials have a tendency to become harder and more slippery on the surface Especially in those cases when the cable is pulled by using a pulling stocking or some other special device which attaches itself to the sheath surface using friction the slippery oversheath material can lead to the pulling device slipping or suddenly losing its grip During transportation During transportation the cables are subjected to mechanical vibrations and small or large movements depending on the packaging drum or cable coil for example This is why the lowest allowed temperatures for cables during transportation are as follows Cables with polyvinyl chloride PVC oversheaths 25 C Cables with polyethylene PE oversheaths 40 C Flame
40. stomer service 01 10 2010 CORRECTION FACTORS FOR ADJACENT THREE PHASE GROUPS INSTALLED STRAIGHT INTO THE GROUND The cable group The amount of adjacent three phase groups distance mm 2 3 4 5 6 8 10 0 touching each other 0 79 0 69 0 63 0 58 0 55 0 50 0 46 70 0 85 0 75 0 68 0 64 0 60 0 56 0 53 250 0 87 0 79 0 75 0 72 0 69 0 66 0 64 The correction factors in the table are suitable for three phase groups made up of three installed as a trefoil or flat formation single core cables when the groups are placed horizontally with the group distances given in the table This table does not apply if the cables are placed in the plastic cable protection pipes installed into the ground these are explained in the table below CORRECTION FACTORS FOR ADJACENT THREE PHASE GROUPS INSTALLED INTO PLASTIC PROTECTIVE PIPES Cable protection pipes The amount of adjacent cable protection pipes distance mm 1 2 3 4 5 6 8 10 0 touching each other 0 80 0 75 0 65 0 60 0 60 0 55 0 55 0 50 70 0 75 0 70 0 65 0 60 0 60 0 55 0 55 250 0 75 0 70 0 70 0 70 0 65 0 65 0 65 The correction factors in the table are used when placing three single core cables into the same cable protection pipe and the cables are loaded evenly The correction factors take into account that the cable protection pipes are not filled If they are after cable installation specially filled with
41. t dynamic short circuit forces the clamps must be selected and installed in such regular intervals that the sufficient strength requirement is achieved Determining the strength of the fastening requires that the clamps dimensions strengths and installation distances are known EXAMPLE Cable clamps suitable for fastening Suitable elastic softening which allows for normal heat expansion movement of a cable must be used between the cable clamps and the cable oversheath Clamps must be tightened in such a way that the cable stays in place and the elastic softening allows for the required heat expansion movement without excessive tightening damaging a cable which is operating at its maximum operating temperature REKA Cables LTD 2010 10 01 Rights for changes reserved GtU HV52145a20101001a en HANDLING AND OPERATING 17 24 INSTRUCTIONS C ABL E S HV Power Cables 52 145 kV R amp D Technical customer service 01 10 2010 If the cable installation is reguired to be flexible due to the heat expansion the fastening distances can be designed to allow cable movement sideways in a way corresponding to warming and cooling EXAMPLE Flexible fastening which allows for heat expansion Clamps made of magnetic material can be used only on the condition that all alternating current conductors go through the same fastening loop or a circuit made of magnetic material Otherwise there will be a risk of circuit currents induced into
42. ted according to the requirements of installation conditions Additional information may be requested from the manufacturer Measuring the optical fibre attenuation As the final production inspection for cables which optionally have optical fibres for temperature measuring REKA Cables LTD has also measured the condition of the optical fibres in order to ensure that the optical fibres in the completed cable have not at the time of delivery exceeded the maximum attenuation values declared in the product technical information Careless handling during the high voltage cable transportation and installation or exceeding the pulling force values or sidewall pressure values can cause mechanical strain to the optical fibres which can lead to damages to optical fibres or they may exceed their maximum attenuation limit values After the cable installation the condition of optical fibres can be measured with reliable measuring equipment which is designed for measuring the specific optical fibre type in the cable The measuring personnel must be skilled and the measuring work accurate in order to achieve a reliable measuring results REKA Cables LTD 2010 10 01 Rights for changes reserved GtU HV52145a20101001a en REKA C A B L E S Reka Cables Ltd Niinist nkatu 8 12 P O Box 12 FI 05801 Hyvink Finland Tel 358 207 200 20 Fax 358 207 200 300 www rekacables com
43. tested at the factory using partial discharge measurement and the high voltage test The condition of the cable insulation can also be verified with the alternating voltage test a c voltage test performed after the cable system installation according to the international standard IEC 60840 2004 section 15 2 as follows Sinusoidal a c voltage freguency 20 300 Hz is connected to the cable for one hour There must not be any breakdown during testing The value of the a c test voltage is determined based on the cable s nominal voltage level Un according to the IEC 60840 2004 table 4 as follows The maximum allowed Test voltage a c in the 1 hour operating voltage for the insulation cable Un voltage test kV kV 52 52 72 5 72 123 128 145 132 Alternatively the a c voltage test for insulation can be made by connecting the nominal voltage Uo to the cable without an extra load for 24 hours There must not be any discharge during testing CAUTION An old fashioned direct current test d c voltage test of insulation for the insulation system is not recommended because it can cause damage to the cable accessories connected to the cable system due to the effect of the direct voltage component on the interface between them For this same reason the direct voltage test has been removed from the international standard IEC 60840 testing methods The charge accumulated in the cable insulation during the alternat
44. trial safety reguirements which must be taken into account according to the authority regulations when planning the work and in different stages of implementing the installation work Checking the product When receiving the product it must be checked immediately that the cable type and make match the delivery documents and the product order and that the product is in good condition The testing values measured during the manufacture are presented in the testing protocols of the production batch When starting the installation procedure make sure that the correct products are being installed Do not start the installation with wrong cable type or if the product is found to have defects or damages O REKA Cables LTD 2010 10 01 Rights for changes reserved GtU HV52145a20101001a en HANDLING AND OPERATING 4 24 INSTRUCTIONS C A BLE HV Power Cables 52 145 kV R amp D Technical customer service 01 10 2010 High voltage cable technical information The product specific technical information and the limits regarding the handling and use for the delivery are explained in the customer contract information The particulars notified as nominal values are always directive theoretical values so the tolerances caused by the production must also be taken into account For example to ensure the sufficient compatibility when selecting cable accessories it is important to also take into account the actual results for the cable diameter or overs
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