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National Standard of the People's Republic of China
GB/T 3956—7997
idt IEC 228:1978
IEC228A:1982
Conductors of insulated cables
Published on October 28, 1997
National Technical Supervision Bureau
Implemented on November 1, 1998
CB/T 3956—1997
This standard is equivalent to the International Electrotechnical Commission (IEC) standard IEC228:1978 "Conductors of Cables" (including the first amendment Amendment No.1:1993) and IEC228A:1982 "Conductors of Cables - Guidelines for the Size Range of Circular Conductors" to revise the standards GR3956-83 "Copper and Aluminum Conductive Cores of Electrical Equipment Wires and Cables" and GB3957—83 "Copper and Aluminum Conductive Cores of Power Cables". This standard is the basic standard for cables and cords. When formulating product standards, conductors suitable for wire and cable products should be selected from the tables of this standard. The "Introduction" in the main text of IEC228 (1978) is intended to explain that the differences between this version and the 1966 version are non-standard content, so when this standard was written, the "Introduction" was moved from the main text of the standard to the "IFC Foreword". IEC:228 (1978) published its first supplement IEC228A "Guidelines for the size range of circular conductors" in 1982, with the purpose of guiding the design of cables and cable connectors. Manufacturing, and ensure the adaptability of the connector and the cable. This standard uses the IEC228 supplement IFC228A as Appendix A of this standard.
This standard will replace GB395683.GB3957-83 from the implementation of II I. Appendix A of this standard is the appendix of the standard. This standard was proposed by the Ministry of Machinery Industry of the People's Republic of China. This standard is under the jurisdiction of the National Wire and Cable Standardization Technical Committee. The drafting unit of this standard: Shanghai Cable Research Institute of the Ministry of Machinery Industry. The main drafters of this standard: Wu Zengquan, Song Cuizhen, GB/T 3956—1997
IEC Foreword
1. IEC (International Electrotechnical Commission) formal resolutions or agreements on technical issues prepared by technical committees on behalf of national committees and for the special concern of national committees, as far as possible, express the international consensus on these issues. 2 These resolutions or agreements are in the form of recommended standards for international use and are recognized by national committees in this sense. 3. In order to promote the unification of national standards, IEC hopes that national committees will adopt the contents of IEC recommended standards as their national standards as far as possible within the scope permitted by their domestic conditions. 1 Any differences between IEC recommended standards and corresponding national standards should be clearly pointed out in the national standards as far as possible.
IEC 228 \ "Conductors of cables" was prepared by IEC Technical Committee 20 "Cables" Subcommittee 20A "High-voltage cables". The Oslo Conference in 1976 discussed the draft of this standard. In June 1977, the draft resolution of this conference was submitted to the National Committees for voting in accordance with the June method in Document 20A (Central Office) No. 60.
The following countries voted to explicitly agree to this publication: Argentina
Australia
Austria
Belgium
Israel
Italy
TEC:228
Other IEC publications used:
JEC28 International Standard for Steel Resistance
IECI11 Resistivity of Industrial Hard Aluminum Wire
Portugal
Romania
Spain
IEC228 Amendment No. 1 was prepared by Subcommittee 20A \ High Voltage Cables \ of IEC Technical Committee 20 "Cables". The text of this amendment is based on the following documents:
June Law/DIS Document
20A(CO)145
Voting Report
20A(CO)153
Voting Full information on this amendment can be found in the voting report listed in the table above. The first supplement to IEC 228, IEC 228A "Guidelines on the size and range of circular conductors", was prepared by IFC Technical Committee 20 "Subcommittee 20A of Cables: High-voltage cables". Its draft was discussed at the Florence Conference in 1980, which decided to send the draft document 20A(CO)76 to the National Committees in December 1980 for voting in accordance with the June Law rules. The following countries voted to expressly approve this publication: Denmark
Australia
Austria
Belgium
Canada
1> Refers to the former German Democratic Republic and the former Soviet Union.
Democratic Germany"
Israel
Italy
Honia
Spain
Turkey
Soviet Union1
GB/T39561997
IEC Introduction
This standard is a revision of IEC228, replacing the first edition of 1966. This standard is intended to serve as a guide for IFC technical committees and national committees in drafting cable standards. Each committee should refer to this general The conductors suitable for a particular route can be selected from the tables of the standard. The appropriate content or appropriate reference can be used in detail in the cable standard. The main purpose of preparing this edition of the standard is to take into account the experience and developments since the publication of the first edition and to simplify the standard as much as possible from the perspective of technical and economic consistency. The types of conductors have been reduced to two. There are two types of conductors for fixed power supply: the first type is solid conductors; the second type is stranded conductors. There are also two types for flexible relays. These two types are consistent with the 196 The 5th and 6th types of the 1960 edition are the same. In order to maintain continuity and avoid confusion, these two numbers are retained. The 3rd and 4th types are relatively less used. Considering that the 2nd and 5th types of this edition are respectively applicable to most of the applications of the 3rd and 4th types in the past, the 3rd and 4th types are deleted. The maximum specified resistance of different types of conductors with the same nominal area can be combined. The provisions are as follows: for the 1st and 2nd types of conductors of the same material and the same nominal cross-section, regardless of whether the conductors are free-form, compressed round, or formed, the maximum conductor resistance of these two conductors used in single-core and multi-core cables is specified to be the same. It seems that in order to avoid too much change from the previous edition, the difference between the resistance values of non-metallic copper conductors and metal-plated copper conductors is still retained. Among these two conductors: the maximum resistance specified for each nominal cross-section of aluminum conductors with a cross-section of 10mm or less is the same as the minimum resistance specified for copper conductors of one size smaller than the aluminum conductor. The purpose of the month is to provide equivalent resistance values between copper and aluminum conductors in small-size cables. The resistance values of copper and lead conductors of mm and above are retained separately, and the same resistance values are specified for uncoated or coated aluminum conductors and aluminum alloy conductors. In order to standardize the resistance values, the size of the single wire used for the same nominal cross-section may vary according to the specific materials used. The resistance values selected for the first and second conductors are the resistance values specified in the 1966 edition for the second conductors of multi-core cables with nominal cross-sections from 2.5mm to 400mm2 and the second conductors of single-core cables with nominal cross-sections of 400mm* and above. For conductors of 1.5nm and below, the difference between the resistance values of the first and second conductors in the 1966 edition is greater than that of other specifications. In order to avoid an increase in resistance, the lower resistance specified for the first conductor of multi-core cables in the 1966 edition is used. Only copper conductors are used for the fifth and sixth soft conductors. The resistance values of these two conductors are the same and conform to the resistance values of multi-core cables specified in the 1966 edition for the fifth conductor. The difference between the resistance values of non-metallized conductors and metallized conductors is retained, and the resistances of single-core and multi-core cables and different types of conductors are combined into the same resistance value. The simplified result makes the resistance calculation method mentioned in the 1966 edition no longer applicable, so it is deleted. For this reason, the values specified in this standard and their sources are summarized, and the method for determining their sources is provided as follows:
Type 1 and Type 2
Copper conductors
1.5 mr and below
2.5-~40 mm
Above 500mm2
Aluminum conductor
10 mm\ and below
16~400 mm2
Above 500mm
Same as the resistance value of the first conductor of multi-core cable in 1966 edition; Same as the resistance value of the second conductor of multi-core cable in 1966 edition; Same as the resistance value of the second conductor of single-core cable in 1966 edition. Compared with the aluminum conductor, the copper conductor resistance value with a nominal cross section smaller than that of the aluminum conductor is: the same as the 1966 edition multi-core cable second conductor resistance value, the same as the 1966 edition single-core cable second conductor resistance value, GH/T3956-1997
fifth and sixth types
the same as the 1966 edition multi-core cable fifth conductor resistance value, the simplified temperature correction coefficient table 5 is simplified by taking the same coefficient for copper and aluminum conductors, so the actual value calculated according to this table is sufficient to be within the accuracy range that can be achieved by the cable conductor temperature and length measurement results. However, more accurate formulas for calculating and aluminum conductor correction coefficients are also listed separately.
1 Scope
National Standard of the People's Republic of China
Conductors of insulated cables
Conductors of insulated cablesGBT3956
idl IEC 228:1978
EC 228A : 1982
Generation GB395683
GB3957-83
This standard specifies the conductors of cables and cords from 0.5 to -2 (00 Iuu The number of wires in the standardized nominal cross-section, the diameter of a single wire and its resistance.
This standard does not apply to conductors for communication circuits. Only when the cable standard specifies, conductors for specially designed cables, such as conductors for medical cables, conductors for extra-soft welding cables, or conductors for special soft cables with extra-short pitch cables, are used. 2 Classification
Conductors are divided into the following types: Type 1, Type 2, Type 5 and Type 6. Types 1 and 2 are intended for conductors for fixed cable laying. Type 1 is a solid conductor. , the second type is a stranded conductor, the fifth and sixth types are intended for use as conductors for ten types of relays and soft wires, and the sixth type is softer than the fifth. 3 Materials
The conductor can be composed of the following materials:
Annealed copper wire without or with metal coating, : Uncoated aluminum or aluminum alloy wire;
The specific provisions of various types of conductors are shown in Chapter 4 and Chapter 5 of this standard. The term "metal coating" means that the conductor is coated with a suitable metal thin layer such as tin, tin alloy or lead alloy. 4 Conductors for fixed number cables
4.1 Solid conductor (Type 1)
Solid conductors shall meet the following requirements.
4.1.1 The conductor shall be composed of the following materials:
Annealed copper wire without metallization or metallization; uncoated aluminum or aluminum alloy wire.
4.1.2 Solid conductors shall have a circular cross section.
Solid copper conductors with a nominal cross section of 2 mm2 and above in Table 1 are only intended for special cables and are not suitable for general-purpose cables.
4.1.3 Solid aluminum conductors with a cross section of 16 mm2 and below shall have a circular cross section. Cross section 25 M1M2 solid aluminum conductor with a sheath of earth; if it is a single-core cable, it should be a flat cross-section; if it is a multi-core cable, it can be a circular cross-section or a shaped cross-section.
Conductors with a cross-section of 95tnm or more can be composed of 5 or less sub-section conductors. 4.1.4 At 20℃, the resistance of the core conductor should not exceed the maximum value specified in the corresponding table. Approved by the State Administration of Technical Supervision on October 28, 1997 and implemented on November 1, 1998
Nominal cross-section
1) See 4.1.2 of this standard.
GB/T 3956—1997
Table 1 The first type of solid conductor for single-core and multi-core cables Maximum conductor resistance at 20℃:, Q/km
Copper conductor
Unplated
Metal-plated
21.5mm to 16mm only aluminum conductor, see 4.1.3.4. 2 Non-compacted stranded circular conductor (second type) Non-compacted stranded circular conductor shall meet the following requirements, 4.2. 1 The conductor shall be composed of the following materials: ． Annealed copper wire without metal plating or metal plating. Unplated aluminum or aluminum alloy wire. bZxz.net
Round or shaped aluminum conductor
The cross-section of stranded aluminum conductor shall generally not be less than 10 mm2, but if 4 mm\ and 6 mm stranded aluminum conductors are specially considered to be suitable for a certain special cable and its use occasion, they are also allowed to be used. 4.2.2 The individual wires in the conductor shall have the same nominal diameter. 4.2.3 The number of individual wires in the conductor shall not be less than the corresponding minimum number specified in Table 2. The minimum number of individual wires is not specified for conductors with cross-sections from 1200 mm to 2000 mm. 4.2.4 The conductor resistance of each core at 20°C shall not exceed the corresponding maximum value specified in Table 2. 4.3 Compacted stranded round conductors and stranded shaped conductors (Type 2) Compacted stranded plaque conductors and stranded shaped conductors shall meet the following requirements. 4.3.1 The conductor shall be composed of the following materials:
Annealed copper wire without metallization or metallization; uncoated aluminum or aluminum alloy wire.
The cross-section of the compacted stranded round aluminum conductor shall not be less than 16 mm2, and the cross-section of the stranded shaped copper or aluminum conductor shall not be less than 25 mm. 4.3.2 The diameter ratio of two different individual wires in the same conductor shall not exceed 2. Nominal cross section
(14G0)
(18co)t
Non-compacted circular conductor
GB/T3956
Table 2 Minimum number of single wires in the second type of stranded conductor for single-core and multi-core cables
Compacted round conductor
1) The dimensions in brackets are non-preferred dimensions. 2) See 4.2.1,
3 of this standard. The minimum number of single wires is not specified. For sheath-type conductors
, the number of single wires in the conductor shall not be less than the minimum number specified in Table 2. For conductors with a cross section of 1200mm to 2000mm, the minimum number of single wires is not specified. 4.3.4 The electrical conductivity of each core conductor at 20℃ shall not exceed the corresponding maximum value specified in Table 2. 5 Soft conductors (Type 5 and Type 6)
Soft conductors shall meet the following requirements:
5.1 The conductor shall be composed of annealed copper wire without or with metal plating. 5.2 The individual wires in the conductor shall have the same nominal diameter. 5.3 The diameter of the individual wires in the conductor shall not exceed the maximum value specified in Table 3 or Table 4. 5.4 The resistance of each conductor at 20°C shall not exceed the maximum value specified in Table 3 or Table 4. The maximum resistance of the conductor at 20°C is,/km
Copper conductor
Unplated
Metal-plated
t1, 076 2
.036 ！
ti. 022 4
0. r:15 1
Aluminum conductor
Nominal surface
Single line in conductor
Most direct inspection
Single line in guide tooth
Standard section
Maximum diameter
6 Inspection requirements
GB/T3956—1997
Table 3 Maximum conductor electric capacity of the fifth type of soft copper conductor 20X: for single-core and multi-core cables
Maximum metal plating||tt| |Metal-plated
Single conductor
Nominal cross section
Expanded diameter
Table 4 Maximum resistance of the sixth type of soft copper conductor for single-core and multi-core cables at 20℃
Not metal-plated
Gold-plated
Nominal cross section
Single conductor in the conductor
Expanded diameter
Maximum resistance of the conductor at 20℃
Not metal-plated
0. 06-4 1
01, 04D 5
3-hour maximum electrical resistance
non-ammonium metal
bonded metal
If practicable, inspection and measurement should be carried out on finished cables to verify compliance with the requirements specified in 4.1.1, 4.1.2.4.1.3, 4.2.1.4.2.2.4.2.3.4.3.1.4.3.2, 4.3.3, 5.1, 5.2 and 5.3 of this standard. Conductor resistance measurement can be carried out on the entire length of the core cable or flexible cable or on a sample of at least 1m in length. After dividing the measured value by its length, compliance with the requirements specified in 4.1.4, 4.2.4, 4.3.4 and 5.4 of this standard can be verified. If necessary, the following formula should be used to correct the conductor resistance to 20r and 1 km long: Ree = R, · K, . L 000
Where: Ra—
20r, 0/km:
R, --C L1 measured resistance of a long cable or cord,K, resistance temperature correction coefficient when the temperature is ℃, length of cable or cord, m;
conductor temperature during measurement, ℃.
Table 5 specifies the temperature correction coefficient K, values within the normal temperature range. Its value is calculated by the following formula: K.
GB/T 3956 —1997
1 + 0. 004(t - 20)
230 +t
This formula is an approximate formula, but it can calculate the actual value within the accuracy range of measuring conductor temperature and cable or cord length. Table 5 Temperature correction coefficient K when measuring conductor resistance at t℃ and correcting it to 20℃. Correction coefficient when measuring conductor temperature
Correction coefficient when measuring conductor temperature
Correction coefficient when measuring conductor temperature
Note, the correction coefficient K in the table is calculated based on the resistance temperature coefficient of 0. 004/C at 20℃. The more accurate temperature correction coefficient formula for copper conductor (non-metallized or metallized conductor) is: Kcu=
234. 5 +f
Aluminum or aluminum alloy conductor
Conductor temperature during measurement
1 + 0.003 93(t - 20)
1 + 0.004 03(t20)
Correction coefficient
0, 962
Resistance overflow coefficient value is listed in IEC28 "International Standard for Copper Resistance\ and IEC111 & Industrial Hard Aluminum Wire Resistivity. Fuze
GB/T 3956—1997
Appendix A
(Standard Appendix)
Guide to the size range of circular conductors
This appendix deals with circular conductors for use in cables. A further supplement has been prepared for solid shaped lead conductors including methods of verifying their dimensions.
Since stranded shaped and aluminium conductors are usually shaped before being connected, it is not necessary to standardise the size ranges for these conductors. A1 Scope and purpose
This appendix is intended as a guide for communication between manufacturers of cables and cable connectors, to help ensure that connectors and cable conductors are compatible with each other, and specifies the size ranges for the following types of conductors in this standard, - Type 1 copper and aluminium solid circular conductors; - Type 2 copper and aluminium non-compacted and compacted stranded circular conductors - Type 5 copper flexible conductors;
Type 6 copper flexible conductors.
A2 Size ranges for circular copper conductors
The point diameter of round copper conductors shall not exceed the values specified in Table A1. For round copper conductors, only the maximum diameter is specified. For stranded (Type 2) copper conductors, the maximum diameter is specified as for non-compacted conductors. This is because the connection joints have a wider diameter for pot conductors than for aluminum conductors. Therefore, in general, the recommended maximum diameter for copper conductors is sufficient to fit the connection joints. In addition, stranded round copper conductors are more often used in non-compacted form than aluminum conductors. If the minimum diameter of Type 1 and Type 2 round copper conductors is required, the minimum diameter of solid and compacted stranded round lead conductors specified in Table A2 can be referred to:
A3 Size range of round aluminum conductors
The diameter of solid round aluminum conductors and compacted stranded round aluminum conductors shall not exceed the maximum value specified in Table A2 and shall not be less than the minimum value specified in Table A2.
Under special circumstances, the maximum diameter of non-compacted stranded round aluminum conductors shall not exceed the corresponding value for steel conductors specified in column 3 of Table A1. Because the size of aluminum conductors varies with the various aluminum materials used and their combinations, the size range is specified for aluminum conductors with a cross-section less than 16mm\.
Because there was no corresponding pressing technology a few years ago, the size range has never been specified for aluminum conductors with a cross-section greater than 630 In. Nominal cross section, mm
GB/T 3956 --1997
Table A1 Maximum diameter of copper conductors
Conductors for fixed-number electrical systems
Solid (first type)
Combined (second type)
Table A2 Minimum and maximum diameters of round-drilled conductors Solid conductor (first type)
Minimum diameter
Maximum diameter
Soft conductor (fifth and sixth types)
Compacted conductor (second type)
Minimum diameter
Maximum diameter
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