Control and instrument cables: laying and handling

Laying temperature and pre-warming

No value of its own was found for this family; these are the values for the sheath material, as for LV power cables.

• The limit is the temperature of the cable itself, not of the air: a drum stored in the cold stays cold after the air warms.Sources: HD 620 Part 1 A.4.12; HD 603 3-G, 5-G, 3-I, 4-B; Nexans 2021 p. 11 (read in the standard text)
• HD 603 3-G, 5-G · HD 620 10-A, 10-C, 10-F: Cable temperature while laying and fitting accessories: at least -5 °C with a PVC sheath, -20 °C with a PE sheath; warm the cable when it is colder.Sources: HD 603 3-G-15 item 2; 5-G-15 item 2; HD 620 10-A-25 item 14; 10-C-26 item 14; 10-F-21 (read in the standard text)

National rules

• United Kingdom PAS 5308-1, PAS 5308-2: Cable and air above 0 °C for the previous 24 hours, or special precautions that keep the cable above 0 °C.Sources: PAS 5308 -1 Annex A, p. 11; -2 Annex A, p. 9 (read in the standard text)

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

Bending radius

• HD 627 4-C1, 4-C2: 12 D while laying; 8 D for one controlled bend.Sources: HD 627 4-C1-15, 4-C2-13 (read in the standard text)
• Anixter: BS 5308 Part 1 Type 1: 8 D while laying.Sources: Anixter Sec. 4 p. 3 (maker's document)
• Prysmian UK: BS 7629-1, BS 8436: 6 D while laying.Sources: Prysmian UK p. 2 (maker's document)

National rules

• Germany DIN VDE 0891-5: J-Y(St)Y...Lg: 7.5 D while laying; 5 D for one controlled bend.Sources: DIN VDE 0891-5 Table 1, p. 3 (read in the standard text)
• United Kingdom PAS 5308-1, PAS 5308-2: Type 1, Type 2: 6 D while laying.Sources: PAS 5308 -1 Table B.1, p. 12; -2 Table B.1, p. 10 (read in the standard text)
• United Kingdom PAS 5308-1: Type 3: 15 D while laying.Sources: PAS 5308 -1 Table B.1, p. 12 (read in the standard text)

Pulling force and method

• HD 627 4-C2: On the conductors 50 N/mm² for copper; on a cable grip 5 × D² N.Sources: HD 627 4-C2-13 5.3 c, d (read in the standard text)
• A swivel between the cable grip and the pulling rope.Sources: HD 620 10-R item 15; Draka p. 6 (read in the standard text)
• 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)

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

National rules

• India IS 1255: At least 0.75 m to the top of the cable for LV and control cables, 0.9 m for 3.3 to 11 kV, 1.05 m for 22 and 33 kV, 1.0 m at road and railway crossings; at least 75 mm of riddled soil or sand below and above, then tiles, bricks or slabs.Sources: IS 1255 6.3.1, 6.3.2, 6.3.6, pp. 16, 19 (read in the standard text)

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