Laying and handling guide

High voltage cables: laying and handling

IEC 60840 and IEC 62067 cables, 45 kV and above.

Every line names every source that states it and how it was seen; where sources disagree, each value is shown with its source. IEC, EN and HD documents and makers come first, national rules after them with their country.

Laying temperature and pre-warming

No value from a standard was found: use the maker's datasheet.

  • Nexans: Warm at +10 °C or more for at least 24 hours, then unreel within 2 hours at about 20 m/min; below -5 °C outside, postpone the pull or warm the drums first.Sources: Nexans 2021 p. 11 (maker's document)

Laying in winter? Pro checks your town and month against this limit. See Pro

Bending radius

  • IEC 60840, IEC 62067: Gives no installation bending radius; the values below come from makers.Sources: IEC 60840 text searched (read in the standard text)
  • TFK, 60 to 400 kV: 25 D while laying.Sources: TFK pdf 35 to 46 (maker's document)
  • Prysmian UK, 66 kV and above: About 30 D as a minimum.Sources: Prysmian UK p. 1 (maker's document)

National rules

  • Türkiye EKAT Çizelge-20: Three-core LV (XLPE or PVC) 12 D; three-core MV 15 D; armoured 15 D; single core 15 D.Sources: EKAT Madde 58 b) 9 (read in the standard text)

Pulling force and method

  • TFK: On the conductors: 50 N/mm² for copper, 30 N/mm² for aluminium.Sources: TFK pdf 35 to 46 (maker's document)
  • Nexans: A pulling eye on the conductors instead of a stocking for lengths over 800 m or conductors over 630 mm².Sources: Nexans 2021 p. 13 (maker's document)
  • Southwire: Work out the tension section by section (straights, slopes, bends) and the sidewall pressure at every bend, and pull from the end that gives the lower maximum.Sources: Southwire 2005 pp. 13 to 17 (maker's document)
  • Watch the tension all through a machine pull and keep the record with the as-laid documents. Prysmian: a winch with a dynamometer, a preset maximum and automatic stop; Draka: without a tension record the maker may refuse a claim.Sources: HD 620 Part 1 A.4.4; HD 603 3-G 3.3; IS 1255 10.3.5; Prysmian 2024 p. 10; Nexans 2021 p. 16; Draka p. 8 (read in the standard text)
  • Sidewall pressure: the maker's limit, checked before the pull at every bend, roller and deflection point; too much tears the sheath.Sources: BS 7846 A.7.4 d); Nexans 2021 p. 17; Anixter Sec. 20 p. 20-44 (read in the standard text)

Work out the pull for your route: the verdict is free, the numbers and the PDF come with Pro. Pull calculation in the cable designer · See Pro

Depth, cover and laying

Snaking in tunnels and troughs: no numbers (amplitude, pitch) were found; CIGRE TB 194 describes the method.

Not found in the research for this family.

  • Nexans: Thermal backfill: keep the specified thickness below and above and the trench width along the whole route, and never mix it with native soil, or the cable overheats.Sources: Nexans 2021 pp. 18 to 19 (maker's document)

Drum handling

  • Keep the drum upright, its axis horizontal, in storage and in transport; never lay it flat on a flange.Sources: HD 620 Part 1 A.3.2.5, A.3.3.2; IS 1255 7.7, p. 25; Prysmian 2024; Reka (read in the standard text)
  • Never drop a drum. Without lifting gear, use a ramp of about 1:4 (IS 1255: 1:3 to 1:4) with ropes or a winch and a sand bed at the foot.Sources: HD 620 Part 1 A.3.3.3; HD 603 3-I 3.3; IS 1255 7.3, p. 24; Prysmian 2024 p. 6; Reka p. 6; Nexans 2021 p. 4 (read in the standard text)
  • Roll it only short distances on firm ground, in the direction of the arrow on the flange.Sources: HD 620 Part 1 A.3.3.4; HD 603 3-I, 3-L; IS 1255 7.4, p. 24; Prysmian 2024 p. 7; Nexans 2021 p. 3 (read in the standard text)
  • Store it on level, firm, well-drained ground and turn it 90° every 3 months.Sources: IS 1255 7.5, 7.6, pp. 24 to 25; Prysmian 2024 p. 8, 9; Nexans 2021 p. 8, 9; Prysmian Türkiye 3.3 (read in the standard text)
  • Leave the battens on until the cable is about to be laid: they keep off sun and knocks.Sources: HD 620 Part 1 A.3.2.5; BS 6622 D.5.2; IS 1255 7.8, p. 25; Nexans 2021 p. 11 (read in the standard text)
  • Cable ends sealed with caps in transport, storage and laying. A cap missing for over a month, or a wet end: cut back 300 mm, check for moisture and cap again.Sources: HD 620 Part 1 A.3.2.3, A.4.7; HD 603 3-I 3.2; BS 6622 C.3; BS 5467 B.4; BS 7846 A.7.4; IS 1255 7.2, p. 24; Nexans 2021 p. 7; Draka (read in the standard text)
  • Pay out tangentially, never over the flange, with the drum on an axle and jacks and braked. Top or bottom: IS 1255 says off the top; Southwire chooses by where the cable goes (the bottom into a floor conduit, the top into a tray); Nexans Belgium says the bottom, for safety.Sources: HD 620 Part 1 A.4.5; IS 1255 8.2, 8.3, 10.2; Southwire 2005 p. 2 to 3; Nexans Belgium FAQ; Prysmian 2024 p. 10; Draka p. 5, 9 (read in the standard text)
  • High voltage drums: lift by crane with a certified spreader bar, do not roll heavy drums and never stack them.Sources: HD 620 Part 1 A.3.3.2, A.3.3.4; Prysmian 2024 p. 6; Nexans 2021 p. 3; Reka p. 4 (read in the standard text)
  • Nexans: Over 10 t of cable: steel drums; wooden drums carry up to 10 t.Sources: Nexans 2021 p. 2 (maker's document)

Every rule for a chosen drum, with its lagging, weight and return terms: Cable drum calculator

Sheath test after laying

  • IEC 60840: A d.c. test of the oversheath to IEC 60229 Clause 5, worded as in IEC 60502-2.Sources: IEC 60840 16.1, 16.2 (read in the standard text)
  • IEC 60229: Installed cable: 4 kV per mm of oversheath thickness, at most 10 kV, for 1 minute (factory test 8 kV per mm, at most 25 kV).Sources: IEC 60229 cl. 5, p. 9; 3.1, p. 6 (read in the standard text)
  • HD 620 10-F, 10-K, 12-K · BS 6622: A d.c. test of the insulation is not recommended: it may harm it.Sources: HD 620 10-F, 10-K, 12-K; BS 6622 (read in the standard text)

The tests after installation for one cable, with their voltages, in the cable designer: Test after installation

Get the commissioning sheet for your own cable with Pro. See Pro

Cable end preparation

The common order of the makers and standards the research found; each step names every source. The lengths depend on the kit: its own instruction decides.

Wonder which lug fits your cable, and how its screen is earthed? See them fitted on your own cable with Pro. See Pro · Members: see them fitted in the designer

  1. Check the kit fits the cable and cut the cable square at its final position.Sources: Ensto PEM1093ENG 2017-04, HIT1 / HOT1 12 to 36 kV (maker's document); TE Raychem ESD-5243-AU-10/09, OXSU-F 36 kV (maker's document); Nexans Euromold IS 24CSJ2-E-09, 12 and 24 kV (maker's document); Prysmian Assembly Instructions 81006A (2022), MST 12 to 36 kV, pp. 1, 3, 4 (maker's document); Nexans Italia IM1778DI.1, MONOi / MONOe-1, p. 2 (1.1) (maker's document); TEDAŞ-MLZ/99-033.B (2023) (read in the standard text)
  2. Straighten the end; heat-treat it where the maker says so.Sources: powerandcables.com, 132 kV termination masterclass (secondary source)
  3. Remove the outer sheath and any graphite or semicon coat; abrade and clean the sheath next to the cut.Sources: Ensto PEM1093ENG 2017-04, HIT1 / HOT1 12 to 36 kV (maker's document); TE Raychem ESD-5243-AU-10/09, OXSU-F 36 kV (maker's document); Nexans Euromold IS 24CSJ2-E-09, 12 and 24 kV (maker's document); Prysmian Assembly Instructions 81006A (2022), MST 12 to 36 kV, p. 4 (maker's document); Nexans Italia IM1778DI.1, MONOi / MONOe-1, p. 2 (maker's document); powerandcables.com, 132 kV termination masterclass (secondary source)
  4. Cut back the armour and the bedding; carry the armour across the joint or bond it to earth.Sources: Prysmian Assembly Instructions 81006A (2022), MST 12 to 36 kV, p. 4 (maker's document); TEDAŞ-MLZ/99-033.B (2023), 2.2.2 (read in the standard text)
  5. Fold the screen wires back over the sheath, or cut the tape screen; bind them and form the earth lead. HV: open the metal sheath.Sources: Ensto PEM1093ENG 2017-04, HIT1 / HOT1 12 to 36 kV (maker's document); TE Raychem ESD-5243-AU-10/09, OXSU-F 36 kV (maker's document); Nexans Euromold IS 24CSJ2-E-09, 12 and 24 kV (maker's document); Prysmian Assembly Instructions 81006A (2022), MST 12 to 36 kV, p. 4 (maker's document); Nexans Italia IM1778DI.1, MONOi / MONOe-1, p. 3 (maker's document); BS 6622:2007, Annex C.6 (read in the standard text); powerandcables.com, 132 kV termination masterclass (secondary source)
  6. Peel the insulation screen back to its cut-back without cutting into the insulation. HV: finish with glass and taper the screen end.Sources: Ensto PEM1093ENG 2017-04, HIT1 / HOT1 12 to 36 kV (maker's document); TE Raychem ESD-5243-AU-10/09, OXSU-F 36 kV (maker's document); Nexans Euromold IS 24CSJ2-E-09, 12 and 24 kV (maker's document); Prysmian Assembly Instructions 81006A (2022), MST 12 to 36 kV, p. 4 (maker's document); Nexans Italia IM1778DI.1, MONOi / MONOe-1, p. 3 (maker's document); powerandcables.com, 132 kV termination masterclass (secondary source); IEC 60502-2:2014, 19.23.3 (read in the standard text); BS 6622 Annex I (read in the standard text)
  7. Smooth the insulation: no conductive traces, no nicks. HV: polish to the maker's grit and measure the diameter.Sources: Ensto PEM1093ENG 2017-04, HIT1 / HOT1 12 to 36 kV (maker's document); TE Raychem ESD-5243-AU-10/09, OXSU-F 36 kV (maker's document); powerandcables.com, 132 kV termination masterclass (secondary source); Prysmian Assembly Instructions 81006A (2022), MST 12 to 36 kV, p. 6 (maker's document)
  8. Cut the insulation back for the lug or connector without nicking the conductor.Sources: Ensto PEM1093ENG 2017-04, HIT1 / HOT1 12 to 36 kV (maker's document); TE Raychem ESD-5243-AU-10/09, OXSU-F 36 kV (maker's document); Nexans Euromold IS 24CSJ2-E-09, 12 and 24 kV (maker's document); Prysmian Assembly Instructions 81006A (2022), MST 12 to 36 kV, p. 7 (maker's document); Nexans Italia IM1778DI.1, MONOi / MONOe-1, p. 3 (maker's document)
  9. Clean from the cable end towards the insulation screen, never the other way.Sources: Ensto PEM1093ENG 2017-04, HIT1 / HOT1 12 to 36 kV (maker's document); Nexans Euromold IS 24CSJ2-E-09, 12 and 24 kV (maker's document); powerandcables.com, 132 kV termination masterclass (secondary source); Prysmian Assembly Instructions 81006A (2022), MST 12 to 36 kV, p. 6 (maker's document)
  10. Fit the stress control over the screen end: tape, mastic or tube, or a moulded cone.Sources: Ensto PEM1093ENG 2017-04, HIT1 / HOT1 12 to 36 kV (maker's document); TE Raychem ESD-5243-AU-10/09, OXSU-F 36 kV (maker's document); Nexans Euromold IS 24CSJ2-E-09, 12 and 24 kV (maker's document); Prysmian Assembly Instructions 81006A (2022), MST 12 to 36 kV, p. 6 (maker's document); Nexans Italia IM1778DI.1, MONOi / MONOe-1, p. 4 (maker's document); TEDAŞ-MLZ/99-033.B (2023) (read in the standard text); powerandcables.com, 132 kV termination masterclass (secondary source)
  11. Crimp or bolt the lug or connector; file sharp edges and fill the gaps.Sources: Ensto PEM1093ENG 2017-04, HIT1 / HOT1 12 to 36 kV (maker's document); TE Raychem ESD-5243-AU-10/09, OXSU-F 36 kV (maker's document); Nexans Euromold IS 24CSJ2-E-09, 12 and 24 kV (maker's document); Prysmian Assembly Instructions 81006A (2022), MST 12 to 36 kV, p. 7 (maker's document); Nexans Italia IM1778DI.1, MONOi / MONOe-1, p. 3 (maker's document); Klauke die HD 13, DIN 46235 die codes (maker's document)
  12. Shrink, push on or cold shrink the insulation and outer protection; fit sheds outdoors and keep the clearances.Sources: Ensto PEM1093ENG 2017-04, HIT1 / HOT1 12 to 36 kV (maker's document); TE Raychem ESD-5243-AU-10/09, OXSU-F 36 kV (maker's document); Nexans Euromold IS 24CSJ2-E-09, 12 and 24 kV (maker's document); Prysmian Assembly Instructions 81006A (2022), MST 12 to 36 kV, pp. 7 to 9 (maker's document); Nexans Italia IM1778DI.1, MONOi / MONOe-1, pp. 4 to 5 (maker's document)
  13. Earth the screen and the armour. HV: run the bonding leads to the link box.Sources: BS 6622:2007, Annex C.6 (read in the standard text); TEDAŞ-MLZ/99-033.B (2023), 2.3.1 (read in the standard text); Prysmian Assembly Instructions 81006A (2022), MST 12 to 36 kV, p. 5 (maker's document); Nexans Italia IM1778DI.1, MONOi / MONOe-1, p. 5 (maker's document); TE Raychem ESD-5243-AU-10/09, OXSU-F 36 kV (maker's document); powerandcables.com, 132 kV termination masterclass (secondary source); IEC 60840:2011, Annex G (read in the standard text)
  14. Test the cable after installation.Sources: IEC 60502-2:2014, clause 20 (read in the standard text); IEC 60840:2011, clause 16 (read in the standard text); HD 620 S3:2023 (read in the standard text)

Want to see this for your own cable, with the cut-back lengths? Cable end preparation in the cable designer · See Pro

In the cable designer

Cable codes of this family

N2XS(FL)2Y · 2XS(FL)2Y

Terms on this page

backfill · bending radius · conduit · cut-back · dynamometer (load cell) · flange · lagging (battens) · oversheath (outer sheath) · pre-warming (pre-heating) · pulling eye · sheath test (oversheath d.c. test) · snaking · spindle (axle) · spreader bar · steel drum · thermal backfill · trench · winch

Sources

Values as the sources print them. For a given job the cable's own standard, the maker's datasheet and the country's rules decide.

Other cable families

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