GB/Z 18890.1-2002 Cross-linked polyethylene insulated power cables with rated voltage of 220 kV (Um=252 kV) and their accessories Part 1: Power cable systems of cross-linked polyethylene insulated power cables with rated voltage of 220 kV (Um=252 kV) and their accessories?
Some standard content:
National Standardization Guiding Technical Documents of the People's Republic of China Power cables with cross-linked polyethylene insulation and their accessories for rated voltage of 220 kV (Um=252 kV) Part 1: Power cable systems Cables with cross-linked polyethylene insulation and their accessories for rated voltage of 220 kV (Um=252 kV) Part 1: Power cable systems Cables with cross-linked polyethylene insulation and their accessories for rated voltage of 220 kV (Um=252 kV) voltageof220kV（Um=252kV）Testmethodsandrequirements1Scope
GB/Z18890.1—2002
eqvIEC62067:2001
This guidance technical document specifies the test methods and requirements for power cable systems of cross-linked polyethylene insulated cables and their accessories for fixed installation with a rated voltage of 220kV (Um=252kV). This test requirement is applicable to single-core cables and their accessories under normal installation and operating conditions, but not to special cables and their accessories, such as submarine cables. For special cables, the tests of this guidance technical document may need to be modified or special test conditions may need to be designed.
2Referenced standards
The provisions contained in the following standards constitute the provisions of this guidance technical document through reference in this guidance technical document. When this guidance technical document is published, the versions shown are valid. All standards will be revised, and parties using this guidance technical document should explore the possibility of using the latest versions of the following standards. GB/T2951.1-1997 General test methods for cable insulation and sheath materials Part 1: General test methods Section 1: Thickness and dimensional measurement - Mechanical properties test (idtIEC60811-1-1: 1993)
GB/T2951.2-1997 General test methods for cable insulation and sheath materials Part 1: General test methods Section 2: Thermal aging test methods (idtIEC60811-1-2: 1985) GB/ T2951.4-1997 General test methods for cable insulation and sheathing materials Part 1: General test methods Section 4: Low temperature test (idtIEC60811-4: 1985) General test methods for cable insulation and sheathing materials Part 2: Special test methods for elastomer mixtures GB/T2951.5-1997
Section 1: Ozone resistance test-heat test-mineral oil immersion test (idtIEC60811-2-1: 1986)|| GB/T2951.6-1997 General test methods for insulation and sheath materials of electric cables Part 2: Special test methods for polyvinyl chloride mixtures Section 1: High temperature pressure test - Anti-cracking test (idtIEC60811-3-1:1985) GB/T2951.7-1997 General test methods for insulation and sheath materials of electric cables Part 3: Special test methods for polyvinyl chloride mixtures Section 2: Weight loss test - Thermal stability test (idtIEC60811-3-21985)
GB/T2951.8-1997 General test methods for cable insulation and sheathing materials Part 4: Special test methods for polyethylene and polypropylene mixtures Section 1: Environmental stress cracking resistance test - Winding test after air heat aging - Melt index measurement method - Measurement method of carbon black and/or mineral filler content in polyethylene (idtIEC60811-4-1: 1985) GB/T2951.2 7—1994 Test methods for mechanical and physical properties of wires and cables Corrosion extension test GB/T2951.28—1994
Test methods for mechanical and physical properties of wires and cables Extrusion jacket scraping test GB/T2952.1—1989
General rules for cable outer sheath
GB/T3048.12—1994 Test methods for electrical properties of wires and cables Partial discharge test (eqvIEC60885-3:1988)
GB/ T3048.13—1992 Test method for impulse voltage of wires and cables (neqIEC60230; 1966) GB/T3956—1997
Conductors of cables (eqvIEC60228: 1978) GB/T12706.2—2002 Extruded insulated power cables and accessories with rated voltage of 1 kV (Um=1.2 kV) to 35 kV (Um=40.5 kV) Part 2: Rated voltage of 6 kV (Um=7.2 kV ) to 30kV (Um=36kV) cables (eqvIEC60502.2:1997) GB/T16927.1-1997 High voltage test technology Part 1: General test requirements (eqvIEC60060-1:1989)
Cable combustion test under flame conditions Part 1: Vertical combustion test method for single insulated wires or cables GB/T18380.12001
(idtIEC60332 1:1998) GB/Z18890.2-2002 Rated voltage 220kV (Um=252kV) cross-linked polyethylene insulated power cable and its accessories Part 2: Rated voltage 220kV (Um=252kV) cross-linked polyethylene insulated power cable
JB/T8996-1999
Guide for selection of high-voltage cables (eqvIEC60183:1984) 3 Definitions
This guidance technical document adopts the following definitions. 3.1 Definition of size (thickness, conductor cross section, etc.) 3.1.1 Nominal value nominalvalue
Specified value and often used in tables. Note: In this guidance technical document, the value usually derived from the nominal value takes into account the specified tolerance, is measured and tested. 3.1.2 Median value
When several values obtained from the test are arranged in ascending (or descending) order, if the number of values is odd, the middle value is the median value; if the number of values is even, the average of the two middle values is the median value. 3.2 Definitions of relevant tests
3.2.1 Routine tests routinetests
Tests performed by the manufacturer on all manufactured lengths of finished cables or each prefabricated insulating part of accessories to verify whether they meet the specified requirements.
3.2.2 Sampling tests sampletests
Tests performed by the manufacturer on samples of finished cables or on certain parts taken from finished cables at a specified frequency to verify whether the cables meet the specified requirements. 3.2.3 Type tests typetests
Tests performed on a type of cable system included in this guidance technical document before delivery according to general commercial principles to prove that it has good performance that can meet the expected conditions of use. The characteristics of this test are: unless the change of the material, design or manufacturing process of the cable or accessories may change its characteristics, the test does not need to be repeated after it is done. 3.2.4 Prequalification test prequalification test is a test conducted on a type of cable system included in this guidance technical document before delivery according to general commercial principles to prove that it has satisfactory long-term performance. Unless there are substantial changes in the materials, manufacturing processes, design and design level related to the cable system, the prequalification test only needs to be carried out once.
Note: Substantial changes are defined as changes that may have an adverse effect on the cable system. If there are changes and it is stated that they do not constitute substantial changes, the supplier shall provide detailed information including test evidence. 3.2.5 Electrical tests after installation electrical tests after installation are tests used to prove that the cable system is intact after installation. 3.3 Cable system cable system
The cable system consists of cables and accessories installed on the cables. 4 Voltage marking and materials
4.1 Rated voltage www.bzxz.net
In this guidance technical document, the symbols Uo, U and U indicate the rated voltage of cables and accessories. The meanings of these symbols are given by JB/T8996.
4.2 Cable insulation materials
The cross-linked polyethylene insulation mixtures for cables to which this guidance technical document applies are listed in Table 1. The table also specifies the maximum operating temperature of the conductor of the cable using this insulation mixture, which is the basis for specifying the test conditions. Table 1 Cross-linked polyethylene insulation mixtures for cables Insulation mixtures
Cross-linked polyethylene (XLPE)
4.3 Cable outer sheath materials
Specify the tests for the following four types of outer sheaths: ST, and ST2 based on polyvinyl chloride; ST, and ST7 based on polyethylene. Normal operation
Maximum conductor temperature/℃
Short circuit (maximum time 5s)
The choice of outer sheath type depends on the cable design and the limitations of mechanical and thermal properties during operation. Note: The temperature limits given in GB/T12706.2 are not required to apply to this guidance technical document. 5 Cable water blocking measures
When the cable system is installed underground, in a tunnel or in water prone to accumulation, it is recommended that the cable has a radial impermeable barrier layer. Note: The conditions for radial water penetration test are not yet available. By agreement between the purchaser and the manufacturer or by recommendation of the manufacturer, the cable may adopt a longitudinal water blocking structure to avoid the need to replace large sections of cable in the event that the cable is damaged in an environment exposed to water. 6 Cable characteristics
In order to implement and record the tests described in this guidance technical document, the cable should be verified. The following characteristics should be known or stated. 6.1 Rated voltage: Uo, U and Um values should be given (see 4.1 and 8.4). 6.2 Conductor type, material and nominal cross-sectional area in square millimeters. If the conductor has a longitudinal water blocking structure, specify the nature of the measures to achieve longitudinal water blocking performance. If the conductor cross-sectional area does not comply with GB/T3956, the DC resistance of the conductor should be stated. 6.3 Insulation material and nominal thickness (see 4.2 and 7.2.1 of GB/Z18890.2-2002). 6.4 Manufacturing process of insulation system.
6.5 If there is water blocking measure at the shield, the nature of the water blocking measure. 6.6 If there is metal shield, the material and structure of the metal shield, such as the number of metal wires and the diameter of the single wire. If there is a metal sheath, its material, structure and nominal thickness. 6.7 Material and nominal thickness of outer sheath.
6.8 Nominal outer diameter of conductor (d).
6.9 Nominal outer diameter of finished cable (D).
Nominal capacitance between conductor and metal shield and (or) metal sheath. 6.10
Accessory characteristics
In order to implement and record the tests described in this guidance technical document, the accessories should be verified. The following characteristics should be known or stated: 7.1 The following points should be correctly indicated for the conductor connection fittings used in the accessories: installation process;
tools, molds and necessary adjustments;
contact surface treatment, if applicable;
type, number and other identification marks of the connection fittings. 7.2 The following points should be correctly marked on the accessories to be tested: manufacturer's name;
accessory type, number, manufacturing date or date code: rated voltage (see 6.1 above);
installation instructions (reference data and date). 8 Test conditions
8.1 Ambient temperature
Unless otherwise specified in detail for special tests, the test should be carried out at an ambient temperature of (20 ± 15) °C. 8.2 Frequency and waveform of power frequency test voltage
The frequency of the power frequency test voltage should be in the range of 49Hz to 61Hz. The waveform should be basically sinusoidal. The voltage value is expressed as an effective value.
8.3 Lightning impulse test voltage waveform
According to GB/T3048.13, the wavefront time of the standard lightning impulse voltage should be 1us~5us, and the half-wave peak time should be 40s~60us. 8.4 Relationship between test voltage and rated voltage The test voltage specified in this guidance technical document is a multiple of the rated voltage U. The U. value and test voltage should be as specified in Table 2.
Table 2 Test voltage
Rated voltage Equipment maximum
Determine the test voltage 9.3 Voltage test
9.2 and 12.4.512.4.7 Thermal cycle 10.11, 12.4.8 and 10.11 and 12.4.8 Partial discharge test
Voltage test
13.2.4 Lightning impulse Lightning impulse voltage
Voltage test
Voltage test after test
The test voltage in this guidance technical document is determined based on the assumption that the cables and accessories are used in the Class A system defined in JB/T8996.
9 Routine test of main insulation of cables and prefabricated accessories 9.1 Overview
The following tests should be carried out on the main insulation of each manufactured length of cable and each prefabricated accessory to verify whether the main insulation of each cable and each prefabricated accessory meets the requirements. The order of these test items is determined by the manufacturer. a) Partial discharge test (see 9.2);
b) Voltage test (see 9.3):
c) Cable outer sheath electrical test (see 9.4). Note: The main insulation of prefabricated accessories includes parts that are in direct contact with the cable insulation and are necessary and basic for controlling the electric field distribution in the accessories, such as pre-molded rubber insulation or epoxy insulation. They can be used alone or in combination to become the necessary insulation and shielding of the accessories.
The main insulation of prefabricated accessories is subject to routine partial discharge and voltage tests. Performed according to the following 1) or 2) or 3). 1) Performed on the main insulation of the prefabricated accessories installed on the cable; 2) Performed with the main insulation parts installed on the accessories specially provided for the test: 3) Tested using a simulated accessory test device so that the electric field strength to which the main insulation parts are subjected reproduces the actual electric field conditions. In cases 2) and 3), the test voltage value shall be selected so that the electric field strength generated is at least the same as the electric field strength generated on the accessory product when the test voltage specified in 9.2 and 9.3 is applied to the accessory product. 9.2 Partial discharge test
The cable shall be subjected to a partial discharge test in accordance with GB/T3048.12, and its sensitivity shall be better than or equal to 5pC as defined in GB/T3048.12. The test of the accessories shall be carried out according to the same principles. 1) The test voltage shall be gradually increased to 222kV (1.75Us) and maintained for 10s, and then slowly reduced to 190kV (1.5U). There shall be no detectable discharge on the test product at 190kV. 9.3 Voltage test
The voltage test shall be carried out at room temperature with power frequency AC voltage. According to the provisions of column 4 of Table 2, the test voltage between the conductor and the metal shield and (or) metal sheath shall be gradually increased to 318kV (2.5U.) and then maintained for 30min. There shall be no insulation breakdown.
9.4 Electrical test of cable outer sheath
According to GB/T2952.1. Apply a DC voltage of 25kV between the metal sheath and the conductive layer on the surface of the outer sheath by connecting the metal sheath to the negative pole. The outer sheath should not be broken down after 1 minute. The conductive layer can be coated on the outer sheath, or the cable can be immersed in water for testing.
1) IEC62067 publication stipulates that the sensitivity is better than or equal to 10pC10
Cable sampling test
10.1 Overview
The following tests should be carried out on samples representing the batch. For test items b) and 9), the cable in a reel may be used as the sample a) Conductor inspection (see 10.4);
b) Conductor resistance measurement (see 10.5);
c) Insulation and outer sheath thickness measurement (see 10.6); d) Metal sheath thickness measurement (see 10.7); e) External diameter measurement (see 10.8) (if required); f) XLPE insulation thermal elongation test (see 10.9); g) Capacitance measurement (see 10.10);
h) Lightning impulse voltage test and subsequent power frequency voltage test (see 10.11); i) Water penetration test (see 12.5.12) (if applicable). 10.2 Test frequency
Sampling Test items a) to g) shall be tested on the same cable taken from each batch of cables of the same type and conductor cross-section, but the number of sampled cables shall not exceed 10% of the number of cables in any contract, rounded to the nearest integer. The test frequency of test items h) and i) shall be based on the agreed quality control method. In the absence of such an agreement, the test shall be carried out according to the following sampling method.
Total number of contracts (single core length) L/km
42 The temperature limits given are not required to apply to this guidance document. 5 Cable water-blocking measures
When the cable system is installed underground, in a tunnel or in water prone to accumulation, it is recommended that the cable has a radially impermeable barrier layer. Note: The conditions for radial water penetration test are not yet available. By agreement between the purchaser and the manufacturer or by the manufacturer's recommendation, the cable may adopt a longitudinal water-blocking structure to avoid the need to replace large sections of the cable in the event that the cable is damaged in an environment exposed to water. 6 Cable characteristics
In order to implement and record the tests described in this guidance document, the cable should be verified. The following characteristics should be known or stated 6.1 Rated voltage: Uo, U and Um values should be given (see 4.1 and 8.4). 6.2 Conductor type, material and nominal cross-sectional area in square millimeters. If the conductor has a longitudinal water-blocking structure, specify the nature of the measures to achieve longitudinal water-blocking performance. If the conductor cross-sectional area does not comply with GB/T3956, the DC resistance of the conductor should be stated. 6.3 Insulation material and nominal thickness (see 4.2 and 7.2.1 of GB/Z18890.2-2002). 6.4 Manufacturing process of insulation system.
6.5 If there is water blocking measure at the shield, the nature of the water blocking measure. 6.6 If there is metal shield, the material and structure of the metal shield, such as the number of metal wires and the diameter of the single wire. If there is a metal sheath, its material, structure and nominal thickness. 6.7 Material and nominal thickness of outer sheath.
6.8 Nominal outer diameter of conductor (d).
6.9 Nominal outer diameter of finished cable (D).
Nominal capacitance between conductor and metal shield and (or) metal sheath. 6.10
Accessory characteristics
In order to implement and record the tests described in this guidance technical document, the accessories should be verified. The following characteristics should be known or stated: 7.1 The following points should be correctly indicated for the conductor connection fittings used in the accessories: installation process;
tools, molds and necessary adjustments;
contact surface treatment, if applicable;
type, number and other identification marks of the connection fittings. 7.2 The following points should be correctly marked on the accessories to be tested: manufacturer's name;
accessory type, number, manufacturing date or date code: rated voltage (see 6.1 above);
installation instructions (reference data and date). 8 Test conditions
8.1 Ambient temperature
Unless otherwise specified in detail for special tests, the test should be carried out at an ambient temperature of (20 ± 15) °C. 8.2 Frequency and waveform of power frequency test voltage
The frequency of the power frequency test voltage should be in the range of 49Hz to 61Hz. The waveform should be basically sinusoidal. The voltage value is expressed as an effective value.
8.3 Lightning impulse test voltage waveform
According to GB/T3048.13, the wavefront time of the standard lightning impulse voltage should be 1us~5us, and the half-wave peak time should be 40s~60us. 8.4 Relationship between test voltage and rated voltage The test voltage specified in this guidance technical document is a multiple of the rated voltage U. The U. value and test voltage should be as specified in Table 2.
Table 2 Test voltage
Rated voltage Equipment maximum
Determine the test voltage 9.3 Voltage test
9.2 and 12.4.512.4.7 Thermal cycle 10.11, 12.4.8 and 10.11 and 12.4.8 Partial discharge test
Voltage test
13.2.4 Lightning impulse Lightning impulse voltage
Voltage test
Voltage test after test
The test voltage in this guidance technical document is determined based on the assumption that the cables and accessories are used in the Class A system defined in JB/T8996.
9 Routine test of main insulation of cables and prefabricated accessories 9.1 Overview
The following tests should be carried out on the main insulation of each manufactured length of cable and each prefabricated accessory to verify whether the main insulation of each cable and each prefabricated accessory meets the requirements. The order of these test items is determined by the manufacturer. a) Partial discharge test (see 9.2);
b) Voltage test (see 9.3):
c) Cable outer sheath electrical test (see 9.4). Note: The main insulation of prefabricated accessories includes parts that are in direct contact with the cable insulation and are necessary and basic for controlling the electric field distribution in the accessories, such as pre-molded rubber insulation or epoxy insulation. They can be used alone or in combination to become the necessary insulation and shielding of the accessories.
The main insulation of prefabricated accessories is subject to routine partial discharge and voltage tests. Performed according to the following 1) or 2) or 3). 1) Performed on the main insulation of the prefabricated accessories installed on the cable; 2) Performed with the main insulation parts installed on the accessories specially provided for the test: 3) Tested using a simulated accessory test device so that the electric field strength to which the main insulation parts are subjected reproduces the actual electric field conditions. In cases 2) and 3), the test voltage value shall be selected so that the electric field strength generated is at least the same as the electric field strength generated on the accessory product when the test voltage specified in 9.2 and 9.3 is applied to the accessory product. 9.2 Partial discharge test
The cable shall be subjected to a partial discharge test in accordance with GB/T3048.12, and its sensitivity shall be better than or equal to 5pC as defined in GB/T3048.12. The test of the accessories shall be carried out according to the same principles. 1) The test voltage shall be gradually increased to 222kV (1.75Us) and maintained for 10s, and then slowly reduced to 190kV (1.5U). There shall be no detectable discharge on the test product at 190kV. 9.3 Voltage test
The voltage test shall be carried out at room temperature with power frequency AC voltage. According to the provisions of column 4 of Table 2, the test voltage between the conductor and the metal shield and (or) metal sheath shall be gradually increased to 318kV (2.5U.) and then maintained for 30min. There shall be no insulation breakdown.
9.4 Electrical test of cable outer sheath
According to GB/T2952.1. Apply a DC voltage of 25kV between the metal sheath and the conductive layer on the surface of the outer sheath by connecting the metal sheath to the negative pole. The outer sheath should not be broken down after 1 minute. The conductive layer can be coated on the outer sheath, or the cable can be immersed in water for testing.
1) IEC62067 publication stipulates that the sensitivity is better than or equal to 10pC10
Cable sampling test
10.1 Overview
The following tests should be carried out on samples representing the batch. For test items b) and 9), the cable in a reel may be used as the sample a) Conductor inspection (see 10.4);
b) Conductor resistance measurement (see 10.5);
c) Insulation and outer sheath thickness measurement (see 10.6); d) Metal sheath thickness measurement (see 10.7); e) External diameter measurement (see 10.8) (if required); f) XLPE insulation thermal elongation test (see 10.9); g) Capacitance measurement (see 10.10);
h) Lightning impulse voltage test and subsequent power frequency voltage test (see 10.11); i) Water penetration test (see 12.5.12) (if applicable). 10.2 Test frequency
Sampling Test items a) to g) shall be tested on the same cable taken from each batch of cables of the same type and conductor cross-section, but the number of sampled cables shall not exceed 10% of the number of cables in any contract, rounded to the nearest integer. The test frequency of test items h) and i) shall be based on the agreed quality control method. In the absence of such an agreement, the test shall be carried out according to the following sampling method.
Total number of contracts (single core length) L/km
42 The temperature limits given are not required to apply to this guidance document. 5 Cable water-blocking measures
When the cable system is installed underground, in a tunnel or in water prone to accumulation, it is recommended that the cable has a radially impermeable barrier layer. Note: The conditions for radial water penetration test are not yet available. By agreement between the purchaser and the manufacturer or by the manufacturer's recommendation, the cable may adopt a longitudinal water-blocking structure to avoid the need to replace large sections of the cable in the event that the cable is damaged in an environment exposed to water. 6 Cable characteristics
In order to implement and record the tests described in this guidance document, the cable should be verified. The following characteristics should be known or stated 6.1 Rated voltage: Uo, U and Um values should be given (see 4.1 and 8.4). 6.2 Conductor type, material and nominal cross-sectional area in square millimeters. If the conductor has a longitudinal water-blocking structure, specify the nature of the measures to achieve longitudinal water-blocking performance. If the conductor cross-sectional area does not comply with GB/T3956, the DC resistance of the conductor should be stated. 6.3 Insulation material and nominal thickness (see 4.2 and 7.2.1 of GB/Z18890.2-2002). 6.4 Manufacturing process of insulation system.
6.5 If there is water blocking measure at the shield, the nature of the water blocking measure. 6.6 If there is metal shield, the material and structure of the metal shield, such as the number of metal wires and the diameter of the single wire. If there is a metal sheath, its material, structure and nominal thickness. 6.7 Material and nominal thickness of outer sheath.
6.8 Nominal outer diameter of conductor (d).
6.9 Nominal outer diameter of finished cable (D).
Nominal capacitance between conductor and metal shield and (or) metal sheath. 6.10
Accessory characteristics
In order to implement and record the tests described in this guidance technical document, the accessories should be verified. The following characteristics should be known or stated: 7.1 The following points should be correctly indicated for the conductor connection fittings used in the accessories: installation process;
tools, molds and necessary adjustments;
contact surface treatment, if applicable;
type, number and other identification marks of the connection fittings. 7.2 The following points should be correctly marked on the accessories to be tested: manufacturer's name;
accessory type, number, manufacturing date or date code: rated voltage (see 6.1 above);
installation instructions (reference data and date). 8 Test conditions
8.1 Ambient temperature
Unless otherwise specified in detail for special tests, the test should be carried out at an ambient temperature of (20 ± 15) °C. 8.2 Frequency and waveform of power frequency test voltage
The frequency of the power frequency test voltage should be in the range of 49Hz to 61Hz. The waveform should be basically sinusoidal. The voltage value is expressed as an effective value.
8.3 Lightning impulse test voltage waveform
According to GB/T3048.13, the wavefront time of the standard lightning impulse voltage should be 1us~5us, and the half-wave peak time should be 40s~60us. 8.4 Relationship between test voltage and rated voltage The test voltage specified in this guidance technical document is a multiple of the rated voltage U. The U. value and test voltage should be as specified in Table 2.
Table 2 Test voltage
Rated voltage Equipment maximum
Determine the test voltage 9.3 Voltage test
9.2 and 12.4.512.4.7 Thermal cycle 10.11, 12.4.8 and 10.11 and 12.4.8 Partial discharge test
Voltage test
13.2.4 Lightning impulse Lightning impulse voltage
Voltage test
Voltage test after test
The test voltage in this guidance technical document is determined based on the assumption that the cables and accessories are used in the Class A system defined in JB/T8996.
9 Routine test of main insulation of cables and prefabricated accessories 9.1 Overview
The following tests should be carried out on the main insulation of each manufactured length of cable and each prefabricated accessory to verify whether the main insulation of each cable and each prefabricated accessory meets the requirements. The order of these test items is determined by the manufacturer. a) Partial discharge test (see 9.2);
b) Voltage test (see 9.3):
c) Cable outer sheath electrical test (see 9.4). Note: The main insulation of prefabricated accessories includes parts that are in direct contact with the cable insulation and are necessary and basic for controlling the electric field distribution in the accessories, such as pre-molded rubber insulation or epoxy insulation. They can be used alone or in combination to become the necessary insulation and shielding of the accessories.
The main insulation of prefabricated accessories is subject to routine partial discharge and voltage tests. Performed according to the following 1) or 2) or 3). 1) Performed on the main insulation of the prefabricated accessories installed on the cable; 2) Performed with the main insulation parts installed on the accessories specially provided for the test: 3) Tested using a simulated accessory test device so that the electric field strength to which the main insulation parts are subjected reproduces the actual electric field conditions. In cases 2) and 3), the test voltage value shall be selected so that the electric field strength generated is at least the same as the electric field strength generated on the accessory product when the test voltage specified in 9.2 and 9.3 is applied to the accessory product. 9.2 Partial discharge test
The cable shall be subjected to a partial discharge test in accordance with GB/T3048.12, and its sensitivity shall be better than or equal to 5pC as defined in GB/T3048.12. The test of the accessories shall be carried out according to the same principles. 1) The test voltage shall be gradually increased to 222kV (1.75Us) and maintained for 10s, and then slowly reduced to 190kV (1.5U). There shall be no detectable discharge on the test product at 190kV. 9.3 Voltage test
The voltage test shall be carried out at room temperature with power frequency AC voltage. According to the provisions of column 4 of Table 2, the test voltage between the conductor and the metal shield and (or) metal sheath shall be gradually increased to 318kV (2.5U.) and then maintained for 30min. There shall be no insulation breakdown.
9.4 Electrical test of cable outer sheath
According to GB/T2952.1. Apply a DC voltage of 25kV between the metal sheath and the conductive layer on the surface of the outer sheath by connecting the metal sheath to the negative pole. The outer sheath should not be broken down after 1 minute. The conductive layer can be coated on the outer sheath, or the cable can be immersed in water for testing.
1) IEC62067 publication stipulates that the sensitivity is better than or equal to 10pC10
Cable sampling test
10.1 Overview
The following tests should be carried out on samples representing the batch. For test items b) and 9), the cable in a reel may be used as the sample a) Conductor inspection (see 10.4);
b) Conductor resistance measurement (see 10.5);
c) Insulation and outer sheath thickness measurement (see 10.6); d) Metal sheath thickness measurement (see 10.7); e) External diameter measurement (see 10.8) (if required); f) XLPE insulation thermal elongation test (see 10.9); g) Capacitance measurement (see 10.10);
h) Lightning impulse voltage test and subsequent power frequency voltage test (see 10.11); i) Water penetration test (see 12.5.12) (if applicable). 10.2 Test frequency
Sampling Test items a) to g) shall be tested on the same cable taken from each batch of cables of the same type and conductor cross-section, but the number of sampled cables shall not exceed 10% of the number of cables in any contract, rounded to the nearest integer. The test frequency of test items h) and i) shall be based on the agreed quality control method. In the absence of such an agreement, the test shall be carried out according to the following sampling method.
Total number of contracts (single core length) L/km
410
Accessory characteristics
In order to implement and record the tests described in this guidance technical document, the accessories should be identified. The following characteristics should be known or stated: 7.1 The conductor connection hardware used in the accessories should correctly indicate the following points: installation process;
tools, dies and necessary adjustments;
- contact surface treatment, if applicable;
type, number and other identification marks of the connection hardware. 7.2 The accessories to be tested should be correctly marked with the following points: manufacturer's name;
- accessory type, number, manufacturing date or date code: rated voltage (see 6.1 above);
installation instructions (reference data and date). 8 Test conditions
8.1 Ambient temperature
Unless otherwise specified in detail for a special test, the test should be carried out at an ambient temperature of (20±15)℃. 8.2 Frequency and waveform of power frequency test voltage
The frequency of power frequency test voltage shall be in the range of 49Hz～61Hz. The waveform shall be basically sinusoidal. The voltage value shall be expressed as effective value.
8.3 Waveform of lightning impulse test voltage
According to GB/T3048.13, the wavefront time of standard lightning impulse voltage shall be 1us～5us, and the half-wave peak time shall be 40s～60us. 8.4 Relationship between test voltage and rated voltage The test voltage specified in this guidance technical document shall be a multiple of the rated voltage U. The U. value and test voltage shall be as specified in Table 2.
Table 2 Test voltage
Rated voltage Equipment maximum
Determine the test voltage 9.3 Voltage test
9.2 and 12.4.512.4.7 Thermal cycle 10.11, 12.4.8 and 10.11 and 12.4.8 Partial discharge test
Voltage test
13.2.4 Lightning impulse Lightning impulse voltage
Voltage test
Voltage test after test
The test voltage in this guidance technical document is determined based on the assumption that the cables and accessories are used in the Class A system defined in JB/T8996.
9 Routine test of main insulation of cables and prefabricated accessories 9.1 Overview
The following tests should be carried out on the main insulation of each manufactured length of cable and each prefabricated accessory to verify whether the main insulation of each cable and each prefabricated accessory meets the requirements. The order of these test items is determined by the manufacturer. a) Partial discharge test (see 9.2);
b) Voltage test (see 9.3):
c) Cable outer sheath electrical test (see 9.4). Note: The main insulation of prefabricated accessories includes parts that are in direct contact with the cable insulation and are necessary and basic for controlling the electric field distribution in the accessories, such as pre-molded rubber insulation or epoxy insulation. They can be used alone or in combination to become the necessary insulation and shielding of the accessories.
The main insulation of prefabricated accessories is subject to routine partial discharge and voltage tests. Performed according to the following 1) or 2) or 3). 1) Performed on the main insulation of the prefabricated accessories installed on the cable; 2) Performed with the main insulation parts installed on the accessories specially provided for the test: 3) Tested using a simulated accessory test device so that the electric field strength to which the main insulation parts are subjected reproduces the actual electric field conditions. In cases 2) and 3), the test voltage value shall be selected so that the electric field strength generated is at least the same as the electric field strength generated on the accessory product when the test voltage specified in 9.2 and 9.3 is applied to the accessory product. 9.2 Partial discharge test
The cable shall be subjected to a partial discharge test in accordance with GB/T3048.12, and its sensitivity shall be better than or equal to 5pC as defined in GB/T3048.12. The test of the accessories shall be carried out according to the same principles. 1) The test voltage shall be gradually increased to 222kV (1.75Us) and maintained for 10s, and then slowly reduced to 190kV (1.5U). There shall be no detectable discharge on the test product at 190kV. 9.3 Voltage test
The voltage test shall be carried out at room temperature with power frequency AC voltage. According to the provisions of column 4 of Table 2, the test voltage between the conductor and the metal shield and (or) metal sheath shall be gradually increased to 318kV (2.5U.) and then maintained for 30min. There shall be no insulation breakdown.
9.4 Electrical test of cable outer sheath
According to GB/T2952.1. Apply a DC voltage of 25kV between the metal sheath and the conductive layer on the surface of the outer sheath by connecting the metal sheath to the negative pole. The outer sheath should not be broken down after 1 minute. The conductive layer can be coated on the outer sheath, or the cable can be immersed in water for testing.
1) IEC62067 publication stipulates that the sensitivity is better than or equal to 10pC10
Cable sampling test
10.1 Overview
The following tests should be carried out on samples representing the batch. For test items b) and 9), the cable in a reel may be used as the sample a) Conductor inspection (see 10.4);
b) Conductor resistance measurement (see 10.5);
c) Insulation and outer sheath thickness measurement (see 10.6); d) Metal sheath thickness measurement (see 10.7); e) External diameter measurement (see 10.8) (if required); f) XLPE insulation thermal elongation test (see 10.9); g) Capacitance measurement (see 10.10);
h) Lightning impulse voltage test and subsequent power frequency voltage test (see 10.11); i) Water penetration test (see 12.5.12) (if applicable). 10.2 Test frequency
Sampling Test items a) to g) shall be tested on the same cable taken from each batch of cables of the same type and conductor cross-section, but the number of sampled cables shall not exceed 10% of the number of cables in any contract, rounded to the nearest integer. The test frequency of test items h) and i) shall be based on the agreed quality control method. In the absence of such an agreement, the test shall be carried out according to the following sampling method.
Total number of contracts (single core length) L/km
410
Accessory characteristics
In order to implement and record the tests described in this guidance technical document, the accessories should be identified. The following characteristics should be known or stated: 7.1 The conductor connection hardware used in the accessories should correctly indicate the following points: installation process;
tools, dies and necessary adjustments;
- contact surface treatment, if applicable;
type, number and other identification marks of the connection hardware. 7.2 The accessories to be tested should be correctly marked with the following points: manufacturer's name;
- accessory type, number, manufacturing date or date code: rated voltage (see 6.1 above);
installation instructions (reference data and date). 8 Test conditions
8.1 Ambient temperature
Unless otherwise specified in detail for a special test, the test should be carried out at an ambient temperature of (20±15)℃. 8.2 Frequency and waveform of power frequency test voltage
The frequency of power frequency test voltage shall be in the range of 49Hz～61Hz. The waveform shall be basically sinusoidal. The voltage value shall be expressed as effective value.
8.3 Waveform of lightning impulse test voltage
According to GB/T3048.13, the wavefront time of standard lightning impulse voltage shall be 1us～5us, and the half-wave peak time shall be 40s～60us. 8.4 Relationship between test voltage and rated voltage The test voltage specified in this guidance technical document shall be a multiple of the rated voltage U. The U. value and test voltage shall be as specified in Table 2.
Table 2 Test voltage
Rated voltage Equipment maximum
Determine the test voltage 9.3 Voltage test
9.2 and 12.4.512.4.7 Thermal cycle 10.11, 12.4.8 and 10.11 and 12.4.8 Partial discharge test
Voltage test
13.2.4 Lightning impulse Lightning impulse voltage
Voltage test
Voltage test after test
The test voltage in this guidance technical document is determined based on the assumption that the cables and accessories are used in the Class A system defined in JB/T8996.
9 Routine test of main insulation of cables and prefabricated accessories 9.1 Overview
The following tests should be carried out on the main insulation of each manufactured length of cable and each prefabricated accessory to verify whether the main insulation of each cable and each prefabricated accessory meets the requirements. The order of these test items is determined by the manufacturer. a) Partial discharge test (see 9.2);
b) Voltage test (see 9.3):
c) Cable outer sheath electrical test (see 9.4). Note: The main insulation of prefabricated accessories includes parts that are in direct contact with the cable insulation and are necessary and basic for controlling the electric field distribution in the accessories, such as pre-molded rubber insulation or epoxy insulation. They can be used alone or in combination to become the necessary insulation and shielding of the accessories.
The main insulation of prefabricated accessories is subject to routine partial discharge and voltage tests. Performed according to the following 1) or 2) or 3). 1) Performed on the main insulation of the prefabricated accessories installed on the cable; 2) Performed with the main insulation parts installed on the accessories specially provided for the test: 3) Tested using a simulated accessory test device so that the electric field strength to which the main insulation parts are subjected reproduces the actual electric field conditions. In cases 2) and 3), the test voltage value shall be selected so that the electric field strength generated is at least the same as the electric field strength generated on the accessory product when the test voltage specified in 9.2 and 9.3 is applied to the accessory product. 9.2 Partial discharge test
The cable shall be subjected to a partial discharge test in accordance with GB/T3048.12, and its sensitivity shall be better than or equal to 5pC as defined in GB/T3048.12. The test of the accessories shall be carried out according to the same principles. 1) The test voltage shall be gradually increased to 222kV (1.75Us) and maintained for 10s, and then slowly reduced to 190kV (1.5U). There shall be no detectable discharge on the test product at 190kV. 9.3 Voltage test
The voltage test shall be carried out at room temperature with power frequency AC voltage. According to the provisions of column 4 of Table 2, the test voltage between the conductor and the metal shield and (or) metal sheath shall be gradually increased to 318kV (2.5U.) and then maintained for 30min. There shall be no insulation breakdown.
9.4 Electrical test of cable outer sheath
According to GB/T2952.1. Apply a DC voltage of 25kV between the metal sheath and the conductive layer on the surface of the outer sheath by connecting the metal sheath to the negative pole. The outer sheath should not be broken down after 1 minute. The conductive layer can be coated on the outer sheath, or the cable can be immersed in water for testing.
1) IEC62067 publication stipulates that the sensitivity is better than or equal to 10pC10
Cable sampling test
10.1 Overview
The following tests should be carried out on samples representing the batch. For test items b) and 9), the cable in a reel may be used as the sample a) Conductor inspection (see 10.4);
b) Conductor resistance measurement (see 10.5);
c) Insulation and outer sheath thickness measurement (see 10.6); d) Metal sheath thickness measurement (see 10.7); e) External diameter measurement (see 10.8) (if required); f) XLPE insulation thermal elongation test (see 10.9); g) Capacitance measurement (see 10.10);
h) Lightning impulse voltage test and subsequent power frequency voltage test (see 10.11); i) Water penetration test (see 12.5.12) (if applicable). 10.2 Test frequency
Sampling Test items a) to g) shall be tested on the same cable taken from each batch of cables of the same type and conductor cross-section, but the number of sampled cables shall not exceed 10% of the number of cables in any contract, rounded to the nearest integer. The test frequency of test items h) and i) shall be based on the agreed quality control method. In the absence of such an agreement, the test shall be carried out according to the following sampling method.
Total number of contracts (single core length) L/km
44). Note: The main insulation of prefabricated accessories includes components that are in direct contact with the cable insulation and are necessary and basic for controlling the electric field distribution in the accessories, such as pre-molded rubber insulation or epoxy insulation. They can be used alone or in combination to become the necessary insulation and shielding of the accessories.
The main insulation of prefabricated accessories is subject to routine partial discharge and voltage tests. Perform according to the following 1) or 2) or 3). 1) Perform on the main insulation of the prefabricated accessories installed on the cable; 2) Perform with the main insulation parts installed on accessories specially designed for testing; 3) Use a simulated accessory test device to test so that the electric field strength to which the main insulation parts are subjected reproduces the actual electric field conditions. In cases 2) and 3), the test voltage value shall be selected so that the electric field strength generated is at least the same as the electric field strength generated on the accessory product when the test voltage specified in 9.2 and 9.3 is applied to the accessory product. 9.2 Partial discharge test
The cable shall be subjected to a partial discharge test in accordance with GB/T3048.12, and its sensitivity shall be better than or equal to 5pC as defined in GB/T3048.12. The test of the accessories shall be carried out according to the same principles. 1) The test voltage shall be gradually increased to 222kV (1.75Us) and maintained for 10s, and then slowly reduced to 190kV (1.5U). There shall be no detectable discharge on the test product at 190kV. 9.3 Voltage test
The voltage test shall be carried out at room temperature with power frequency AC voltage. According to the provisions of column 4 of Table 2, the test voltage between the conductor and the metal shield and (or) metal sheath shall be gradually increased to 318kV (2.5U.) and then maintained for 30min. There shall be no insulation breakdown.
9.4 Electrical test of cable outer sheath
According to GB/T2952.1. Apply a DC voltage of 25kV between the metal sheath and the conductive layer on the surface of the outer sheath by connecting the metal sheath to the negative pole. The outer sheath should not be broken down after 1 minute. The conductive layer can be coated on the outer sheath, or the cable can be immersed in water for testing.
1) IEC62067 publication stipulates that the sensitivity is better than or equal to 10pC10
Cable sampling test
10.1 Overview
The following tests should be carried out on samples representing the batch. For test items b) and 9), the cable in a reel may be used as the sample a) Conductor inspection (see 10.4);
b) Conductor resistance measurement (see 10.5);
c) Insulation and outer sheath thickness measurement (see 10.6); d) Metal sheath thickness measurement (see 10.7); e) External diameter measurement (see 10.8) (if required); f) XLPE insulation thermal elongation test (see 10.9); g) Capacitance measurement (see 10.10);
h) Lightning impulse voltage test and subsequent power frequency voltage test (see 10.11); i) Water penetration test (see 12.5.12) (if applicable). 10.2 Test frequency
Sampling Test items a) to g) shall be tested on the same cable taken from each batch of cables of the same type and conductor cross-section, but the number of sampled cables shall not exceed 10% of the number of cables in any contract, rounded to the nearest integer. The test frequency of test items h) and i) shall be based on the agreed quality control method. In the absence of such an agreement, the test shall be carried out according to the following sampling method.
Total number of contracts (single core length) L/km
44). Note: The main insulation of prefabricated accessories includes components that are in direct contact with the cable insulation and are necessary and basic for controlling the electric field distribution in the accessories, such as pre-molded rubber insulation or epoxy insulation. They can be used alone or in combination to become the necessary insulation and shielding of the accessories.
The main insulation of prefabricated accessories is subject to routine partial discharge and voltage tests. Perform according to the following 1) or 2) or 3). 1) Perform on the main insulation of the prefabricated accessories installed on the cable; 2) Perform with the main insulation parts installed on accessories specially designed for testing; 3) Use a simulated accessory test device to test so that the electric field strength to which the main insulation parts are subjected reproduces the actual electric field conditions. In cases 2) and 3), the test voltage value shall be selected so that the electric field strength generated is at least the same as the electric field strength generated on the accessory product when the test voltage specified in 9.2 and 9.3 is applied to the accessory product. 9.2 Partial discharge test
The cable shall be subjected to a partial discharge test in accordance with GB/T3048.12, and its sensitivity shall be better than or equal to 5pC as defined in GB/T3048.12. The test of the accessories shall be carried out according to the same principles. 1) The test voltage shall be gradually increased to 222kV (1.75Us) and maintained for 10s, and then slowly reduced to 190kV (1.5U). There shall be no detectable discharge on the test product at 190kV. 9.3 Voltage test
The voltage test shall be carried out at room temperature with power frequency AC voltage. According to the provisions of column 4 of Table 2, the test voltage between the conductor and the metal shield and (or) metal sheath shall be gradually increased to 318kV (2.5U.) and then maintained for 30min. There shall be no insulation breakdown.
9.4 Electrical test of cable outer sheath
According to GB/T2952.1. Apply a DC voltage of 25kV between the metal sheath and the conductive layer on the surface of the outer sheath by connecting the metal sheath to the negative pole. The outer sheath should not be broken down after 1 minute. The conductive layer can be coated on the outer sheath, or the cable can be immersed in water for testing.
1) IEC62067 publication stipulates that the sensitivity is better than or equal to 10pC10
Cable sampling test
10.1 Overview
The following tests should be carried out on samples representing the batch. For test items b) and 9), the cable in a reel may be used as the sample a) Conductor inspection (see 10.4);
b) Conductor resistance measurement (see 10.5);
c) Insulation and outer sheath thickness measurement (see 10.6); d) Metal sheath thickness measurement (see 10.7); e) External diameter measurement (see 10.8) (if required); f) XLPE insulation thermal elongation test (see 10.9); g) Capacitance measurement (see 10.10);
h) Lightning impulse voltage test and subsequent power frequency voltage test (see 10.11); i) Water penetration test (see 12.5.12) (if applicable). 10.2 Test frequency
Sampling Test items a) to g) shall be tested on the same cable taken from each batch of cables of the same type and conductor cross-section, but the number of sampled cables shall not exceed 10% of the number of cables in any contract, rounded to the nearest integer. The test frequency of test items h) and i) shall be based on the agreed quality control method. In the absence of such an agreement, the test shall be carried out according to the following sampling method.
Total number of contracts (single core length) L/km
4
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