North American cables: laying and handling

Laying temperature and pre-warming

• Southwire: Lowest air temperature for installation: PVC -10 °C; CSPE or CPE -20 °C; EPR, PE and XLPE -40 °C. Keep the reels at least 24 hours in heated storage first and pull more slowly. THHN and PVC-jacketed MC and TC cables follow the PVC line; XHHW, MV-90 and MV-105 the -40 °C line, unless the maker's sheet says otherwise.Sources: Southwire 2005 p. 2 to 3 (maker's document)

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

Bending radius

• NEC 300.34: Over 1000 V: 8 D unshielded, 12 D shielded or lead-covered, during and after installation.Sources: NEC (Southwire CTS0004) Table 2 (secondary source)
• NEC 330.24: MC cable: 7 D with an interlocked or corrugated sheath; smooth sheath 10 D up to 0.75 in diameter, 12 D up to 1.5 in, 15 D above.Sources: NEC (Southwire CTS0004) Table 1 (secondary source)
• NEC 334.24, 336.24, 338.24, 340.24 · ICEA S-95-658: TC and unshielded, unarmoured cables: 4 D up to 1 in diameter, 5 D up to 2 in, 6 D above; TC with metallic shielding 12 D; NM, SE, USE and UF cables 5 D.Sources: NEC (Southwire CTS0004) Table 1; ICEA (Service Wire) p. 104 (secondary source)

Pulling force and method

• Southwire: On the conductors 0.008 lb/cmil for copper (70.2 N/mm²) and 0.006 lb/cmil for AA-8000 aluminium (52.7 N/mm²); a pulling eye at most 10 000 lb, a basket grip 1000 lb.Sources: Southwire 2005 Table 4, p. 10; Southwire 2024 (maker's document)
• Southwire: Sidewall pressure: 500 lb/ft for 600 V and 5 to 15 kV cables, 300 lb/ft for 25 to 35 kV and interlocked armour (2005); 1000 lb/ft for 8 AWG and larger (2024).Sources: Southwire 2005 Table 7, p. 16; Southwire 2024 p. 1 (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)
• Guide the cable into a duct along its axis, with a bell mouth at the duct end, in one continuous arc without a reverse bend.Sources: BS 7846 A.7.4 f); IS 1255 6.3.4.4, 6.4.1; Nexans 2021 p. 17; Southwire 2005 p. 3 (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

• NEC Table 300.5: Cover, 0 to 1000 V: direct burial 24 in (600 mm); rigid or intermediate metal conduit 6 in (150 mm); listed nonmetallic raceway 18 in (450 mm); under streets, driveways and parking lots 24 in.Sources: NEC (study guides) (secondary source)
• NEC Table 300.50: Over 1000 V to 22 kV, direct buried: 30 in (750 mm).Sources: NEC (study guides) (secondary source)
• NEC Chapter 9 Table 1: Conduit fill: one cable 53 %, two cables 31 %, more than two 40 %; a multiconductor cable counts as one.Sources: NEC Chapter 9 (study guides); Southwire 2005 Table 8 (secondary source)

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)

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

Sheath test after laying

No sheath test after laying was found for this family.

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