GB/T 3956-2008Conductors of insulated cables (English PDF)

4.3 of this Standard);

- Conductor's cross-sectional ranges of the first class of solid aluminum

conductor and the second class of stranded aluminum conductor for single

and multi-core cables use have respectively been expanded to 2000 m2

and 2500 m2 (Table 1 and Table 2 of previous edition, Table 1 and Table 2

of this Standard);

- Added resistance requirements for solid aluminum conductor (5.1.1 and

5.1.2 of this Standard);

- Modified requirements on cross-sectional range for stranded circular non-

compacted conductors (5.2.1 of previous edition, 5.2.1 of this Standard);

- Added requirements on cross-section for stranded compacted circular

conductors and stranded shaped conductors (5.3.1 of this Standard);

- Deleted Clause 6 of previous edition;

- Added measurement of resistance (Annex A of this Standard);

- Added exact formulae for the temperature correction factors (Annex B of

this Standard) .

Annex A of this Standard is normative; Annex B and Annex C are informative.

This Standard was proposed by China Electrical Equipment Industry

Association.

This Part shall be under the jurisdiction of National Technical Committee on

Wire and Cable of Standardization Administration of China (SAC/TC 213).

The drafting organizations of this Standard: Shanghai Electric Cable Research

Institute, Tianjin Plastic Power Cable Group Co., Ltd., TBEA Shandong Luneng

Taishan Cable Co., Ltd., Qingdao Hanhe Cable Co., Ltd., Far East Holding

Group Co., Ltd., Fujian Nanping Nanxian Cable Co., Ltd., and Wuxi Jiangnan

Cable Co., Ltd..

Main drafters of this Standard: Xu Xiaofeng, Han Changwu, Gao Yumin, Zhao

Xinyuan, Wang Chuanbin, Lin Qiqing and Liu Jun.

This Standard replaces the following previous standards:

- GB/T 3956-1983, GB/T 3956-1997;

- GB/T 3957-1983.

Conductors of insulated cables

2.1 metal-coated

coated with a thin layer of suitable metal, such as tin or tin alloy.

2.2 nominal cross-sectional area

value that identifies a particular size of conductor but is not subject to direct

measurement.

NOTE Each particular size of conductor in this Standard is required to meet a maximum

resistance value.

b) Stranded aluminium or aluminium alloy conductors shall have a cross-

sectional area not less than 10 mm2.

c) The wires in each conductor shall all have the same nominal diameter.

d) The number of wires in each conductor shall be not less than the

appropriate minimum number given in Table 2.

5.2.2 Resistance

The resistance of each conductor at 20°C, when determined in accordance with

Clause 7, shall not exceed the appropriate maximum value given in Table 2.

5.3 Stranded compacted circular conductors and stranded shaped

conductors (class 2)

5.3.1 Construction

a) Stranded compacted circular conductors and stranded shaped conductors

(class 2) shall consist of one of the materials specified in Clause 4.

Stranded compacted circular aluminium or aluminium alloy conductors

shall have a nominal cross-sectional area not less than 10 mm2. Stranded

shaped copper, aluminium or aluminium alloy conductors shall have a

nominal cross-sectional area of not less than 25 mm2.

b) The ratio of the diameters of two different wires in the same conductor

shall not exceed 2.

c) The number of wires in each conductor shall be not less than the

appropriate minimum number given in Table 2.

NOTE This requirement applies to conductors made with wires of circular cross-section before

compaction and not to conductors made with pre-shaped wires.

5.3.2 Resistance

The resistance of each conductor at 20°C, when determined in accordance with

Clause 7, shall not exceed the appropriate value given in Table 2.

6.1 Construction

a) Flexible conductors (classes 5 and 6) shall consist of plain or metal-coated

annealed copper.

b) The wires in each conductor shall have the same nominal diameter.

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