LINK BOXES Cross bonding and sectionalisation for …

1 LINK BOXESC ross bonding and sectionalisationfor high-voltage cable systemsRApplications Direct grounding Single point bonding Cross bonding Cross bonding and transposition Sheath voltage limiters (SVL)Features Compact design Stainless steel Hermetically sealed 1-phase and 3-phase BOXES Sheath voltage limiters (SVL)LinkboxBrosch 16:05 Uhr Seite 5 Link BOXES and sheath voltage limitersLink BOXES are used with cable joints and terminations to provide easy access to shieldbreaks for test purposes and to limit voltagebuild-up on the sheath. Lightning, fault currents and switching operations can causeovervoltages on the cable sheath.

2 The link boxoptimizes loss management in the cable shieldon cables grounded both design Made of stainless steel Compact design 1-phase and 3-phase link BOXES Hermetically sealed- Resists water pressure up to 1 bar (20 psi)- Lugs and bonding cables are heatshrinksealed inside and outside Suitable for different applications- Single point bonding - Cross bonding - Direct grounding- Grounding through SVL- Combined direct and SVL grounding- Cross bonding and transpositionElectrical design Grounding box Link box- ZnO sheath voltage limiter- 3 kV and 6 kV protection levels- Same outer dimensions for both levelsApplication Can be installed in pits or vaults and onstructures or poles Use with single core or concentric bondinglead Cross section up to 120 mm2*)

3 Type tests Tested to ANSI/IEEE Std 575-1988 IEEE Guide for the application of sheath- bonding methods for single conductor cablesand the calculation of induced voltages andcurrents in cable sheaths CIGRE/ELECTRA recommendations for Cross bonding *) Larger cable Cross sections on requestLINK BOXESC ross bonding and sectionalisationfor high-voltage cable systemsLink box installed with Cross bonding cablesGrounding boxLink box with sheath voltage limiters (SVL)LinkboxBrosch 16:04 Uhr Seite 2 Single point bondingThis is the simplest form of special sheaths of the three cable sections areconnected and grounded at one point onlyalong their length.

4 At all other points, there willbe a voltage between sheath and ground thatwill be at its maximum at the farthest pointfrom the ground bond. The sheaths musttherefore be adequately insulated from there is no closed sheath circuit, exceptthrough the sheath voltage limiter, current does not normally flow longitudinally along thesheaths and no sheath circulation current bonding and transpositionIn addition to Cross bonding the shield, theinduced voltage can be reduced by cyclicallytransposing the main conductors of the 3-phase bondingFor Cross bonding , the cable length is dividedinto three approximately equal sections. Eachof the three alternating magnetic fields inducesa voltage with a phase shift of 120 in thecable shields.

5 The Cross bonding takes place inthe link BOXES . Ideally, the vectorial addition ofthe induced voltages results in Uires= 0. Inpractice, the cable length and the laying condi-tions will vary, resulting in a small residualvoltage and a negligible current. Since there isno current flow, there are practically no lossesin the screen. The total of the three voltages iszero, thus the ends of the three sections canbe bonding system:1L1L2L323UL1UL2UL3 Sealing end (termination)Cable sheathsCable sheathsStraight joints with insulated flangeLink box with SVLLink box with SVLLink box with SVLLink boxLink boxLink boxEarth continuity conductora) Cross bonding of shieldsb) Induced voltages in 3-phase configurationUiresCross bonding layout of a transmission cablesystemLinkboxBrosch 16.

6 04 Uhr Seite 3L Tyco Electronics EPP 0865 7/00 DescriptionNumberSheath voltage Dimensionsof phaseslimiterL (mm)W (mm)H (mm)EPPA-055-0/1 Direct grounding1---300190165 EPPA-055-3/1 Cross bonding13 kV300190165 EPPA-055-6/1 Cross bonding16 kV300190165 EPPA-055-0/3 Direct grounding3---310310255 EPPA-055-3/3 Cross bonding33 kV310310255 EPPA-055-6/3 Cross bonding36 kV310310255 Literature:Test Report PPR 1168 Type Test of Link Box LBOX3-ZnO-3 PPR 1449 Type Test of Link Box EPPA-055-6/31-Phase Link box3-Phase Link boxLINK BOXESC ross bonding and sectionalisationfor high-voltage cable of the above information, including drawings, illustrations and graphic designs, reflects our present understanding and is to the best of our knowledge and belief correct and reliable.

7 Users, however, shouldindependently evaluate the suitability of each product for the desired application. Under no circumstances does this constitute an assurance of any particular quality or performance. Such an assurance is only provided in the context of our product specifications or explicit contractual arrangements. Our liability for this product is set forth in our standard terms and conditions of sale. AMP, DULMISON, HELLSTERN, RAYCHEM, SIMEL are trademarks of Tyco International Electronics Raychem GmbHEnergy DivisionHaidgraben 6, 85521 Ottobrunn/Munich, GermanyPhone: ++49-89-6089-0, Fax: ++49-89-6096345 ArgentinaPhone: ++54-11-4733 2277 Fax: ++54-11-4733 2267 AustraliaPhone: ++61-2-4390 1111 Fax: ++61-2-4353 2497 BrazilPhone: ++55-11-861 1311 Fax: ++55-11-861 1862 CanadaPhone: ++1-905-475 6222 Fax: ++1-905-470-4453 FrancePhone: ++33-3-80583200 Fax: ++33-3-80341015 MexicoPhone: ++52-5-729 0405 Fax: ++52-5-361-8545 ThailandPhone: ++66-2-7394026 - 32 Fax.

8 ++66-2-3260563 - 64 United States of AmericaPhone: ++1-800-327-6996 Fax: ++1-800-527-8350 LinkboxBrosch 9:37 Uhr Seite 4