This standard specifies the following test methods: - Test method 5: resistance - Test method 13: breakdown voltage - Test method 14: film continuity - Test method 19: dielectric loss factor Definition, general test method and winding wire test method list refer to GB/T 4074.1. GB/T 4074.5-1999 Winding wire test method Part 5: Electrical properties GB/T4074.5-1999 Standard download decompression password: www.bzxz.net

GB/T4074.1~4074.6—1999
This standard is equivalent to the International Electrotechnical Commission (IEC) standard IEC60851 "Winding Wire Test Method" series of standards. This series of standards are:
IEC60851-1:1996
IEC60851-2:1996
IEC60851-3.1996
IEC60851-4:1997
IEC60851-5.1996
IEC60851-6:1996
Winding Wire Test Method Test methods
Part 1: General provisions
Test methods for winding wires
Part 2: Dimensional measurement
Test methods for winding wires
Part 3: Mechanical properties
Test methods for winding wires
Part 4: Chemical properties
Test methods for winding wires Part 5: Electrical properties Test methods for winding wires
Part 6: Thermal properties||t t||Corresponding to the IEC60851 series of standards, this standard is divided into the following parts under the general title of "Test methods for winding wires": Test methods for winding wires Part 1: General provisions GB/T4074.1—1999
GB/T4074.2—1999
Test methods for winding wires Part 2: Dimensional measurement GB/T4074.3—1999
Test methods for winding wires Part 3: Mechanical properties Test methods for winding wires Part 4: Chemical properties GB/T4074.4—1999
GB/T4074.5—1999
Test methods for winding wires Part 5: Electrical properties GB/T4074.6—1999
Test methods for winding wires Part 6: Thermal properties Parts 2, 3, 4, 5 and 6 should be used together with Part 1. According to the provisions of GB/T1.1-1993 and the first amendment (1995), the foreword of the adopted object should be retained when adopting an international standard. Since the IEC60851 standard consists of 6 parts, all 6 parts have a foreword. Therefore, they are combined into the "IEC Foreword" of this standard. The "Introduction" of each part is also combined into the IEC Introduction of this standard. In addition, some editorial errors in IEC60851 were corrected when formulating this standard.
This standard cancels GB/T4074.15-1983\Reciprocating paint scraping test method", GB/T4074.18-1983\Breakdown voltage aluminum foil method", GB/T4074.28-1983 trichloroethylene and methanol extraction method", GB/T4074.30-1983\Chlorodifluoromethane solvent method" and GB/T4074.31-1983\Chlorodifluoromethane foaming method". This standard adds the self-adhesive layer thickness of enameled round wire, the bonding strength of twisted coils and the friction test methods. This standard revises GB/T4074.23-1983 "Test method for resistance to water-containing transformer oil". This standard retains the type test (T), extraction test (T) and extraction test (T) in GB/T4074.1-1983. The definitions of sample test (S) and routine test (R) are used to facilitate the implementation of the enameled wire product standard. Since the first amendment to IEC60172 (1998) has specified the temperature index determination method for enameled flat wire and film wrapped wire, the test method 15 "Temperature Index" in Part 6 "Thermal Properties" of this standard has been modified accordingly. This standard replaces GB/T4074-1983 and GB/T1343-1984 standards from the date of implementation. The appendices to this standard are all suggestive appendices. This standard was proposed by the State Bureau of Machinery Industry. This standard is under the jurisdiction of the National Technical Committee for Standardization of Wires and Cables. The main drafting units of this standard: Shanghai Cable Research Institute, Fuzhou Datong Electromechanical Co., Ltd., Tongling Jingda Copper Materials Group Co., Ltd., Zhengzhou Electromagnetic Wire Factory, Hengyang Instrument Machinery Factory. The main drafters of this standard: Chen Huimin, Shu Yingchun, Zheng Qirong, Zhu Qiang, Hu Jie, Yin Yuelu. 1
GB/T4074.14074.6—1999
IEC Foreword
1.IEC (International Electrotechnical Commission) is an international standardization organization composed of national electrotechnical committees (IEC National Committees). The purpose of EC is to promote international cooperation on all issues of standardization in the electrical and electronic fields. To achieve this purpose, in addition to organizing various activities, EC also publishes international standards and entrusts technical committees to formulate these standards. Any national committee interested in a certain standard may participate in the formulation of the standard. 2. Technical Committee IEC formal resolutions or agreements drawn up on behalf of the National Committees on technical issues of particular concern to them express as far as possible the international consensus on these issues. 3 These resolutions or agreements are published in the form of standards, technical reports or guidelines, which are used internationally in the form of recommended documents and are recognized by the National Committees in this sense. 4 In order to promote international unification, the IEC National Committees frankly adopt IEC International Standards in their countries and regions to the greatest extent possible. Any differences between EC standards and corresponding national or regional standards should be clearly pointed out in the national or regional standards. 5. IEC does not provide a marking method to indicate IEC approval, nor does IEC assume responsibility for any equipment that claims to comply with the requirements of a standard.
6. It must be noted that some of the contents of this international standard may be subject to patent rights. IEC shall not be responsible for identifying any or all such patent rights.
International Standard IEC60851-160851-6 was prepared by IEC Technical Committee 55 "Winding Wire". The second edition of IEC60851-1 standard cancels and replaces the first edition of 1985 and makes technical revisions. The text of this standard is based on the following documents: FDIS Documents
55/470A/FDIS
Voting Report
55/511/RVD
Full information on the voting for the approval of this standard can be found in the "Voting Report" listed in the table above. Appendix A is an informative appendix only.
The second edition of IEC60851-2 standard cancels and replaces the first edition published in 1985 and Amendment No. 1 (1992), and is technically revised.
The text of this standard is based on the following documents: FDIS Documents
55/471A/FDIS
Voting Report
55/512/RVD
Full information on the voting for the approval of this standard can be found in the "Voting Report" listed in the table above. The first amendment to IEC60851-2 is based on the following documents: FDIS Document
55/587/FDIS
Voting Report
55/605/RVD
All information on the voting to approve this standard can be found in the "Voting Report" listed in the table above. 1
GB/T4074.1~4074.6—1999
The second edition of IEC60851-3 standard cancels and replaces the first edition published in 1985 and its first and second amendments (1992), and makes technical revisions.
The text of this standard is based on the following documents:FDIS Document
55/472A/FDIS
Voting Report
55/513/RVD
Full information on the voting for the approval of this standard can be found in the "Voting Report" listed in the table above. Appendices A and B are only informative appendices. Amendment No. 1 to IEC60851-3 is based on the following documents:FDIS Document
55/592/FDIS
Voting Report
55/612/RVD
Full information on the voting for the approval of this standard can be found in the "Voting Report" listed in the table above. The second edition of IEC60851-4 standard cancels and replaces the first edition published in 1985 and its amendment No. 1 (1992), and makes technical revisions.
The text of this standard is based on the following documents: FDIS Documents
55/473A/FDIS
Voting Report
55/514/RVD
Full information on the voting and approval of this standard can be found in the "Voting Report" listed in the table above. Amendment No. 1 to IEC60851-4 is based on the following documents: FDIS Documents
55/597/FDIS
Voting Report
55/614/RVD
Full information on the voting and approval of this standard can be found in the "Voting Report" listed in the table above. IEC60851-4 Amendment No. 2.The first edition is a combination of the second edition of EC60851-4 (1996) and its first amendment (1997). The third edition of IEC60851-5 standard cancels and replaces the second edition published in 1988 and its first amendment (1990), and makes technical revisions.
This standard text is based on the following documents: FDIS document
55/474A/FDIS
Voting report
55/515/RVD
Full information on the voting to approve this standard can be found in the "Voting Report" listed in the table above. The first amendment to IEC60851-5 is based on the following documents:1
GB/T4074.1～4074.6—1999
FDIS Document
55/542/FDIS
Voting Report
55/572/RVD
Full information on the voting for the approval of this standard can be found in the "Voting Report" listed in the table above. The second edition of IEC60851-6 standard cancels and replaces the first edition published in 1985 and makes technical revisions. The text of this standard is based on the following documents:FDIS Document
55/475A/FDIS
Voting Report
55/516/RVD
Full information on the voting for the approval of this standard can be found in the "Voting Report" listed in the table above. Appendix A is an informative appendix only.
The first amendment to IEC60851-6 is based on the following documents:FDIS Document
55/561/FDIS
Voting Report
55/593/RVD
All information on the voting to approve this standard can be found in the "Voting Report" listed in the table above. N
GB/T4074.14074.6—1999
GB/T4074.1~4074.6 is a part of the series of standards for insulated wires for windings of electrical equipment. This series of standards consists of 3 parts:
a) Test methods (GB/T4074);
b) Product standards (IEc60317);
c) Packaging (JB/T8135).
1 Scope
National Standard of the People's Republic of China
Test methods for winding wiresPart 5. Electrical properties
This standard specifies the following test methods:
-Test method 5: Resistance
-Test method 13: Breakdown voltage
-Test method 14: Paint film continuity
-Test method 19: Dielectric loss factor
GB/T 4074.5—1999
idtIEC 60851-5:1996
Amendment No.1:1997
Replaces GB/T4074.17~4074.19—1983GB/T4074.21991
GB/T4074.22—1983
GB/T1343.8~1343.9—1984
For definitions, general principles of test methods and a list of winding wire test methods, see GB/T4074.1.2 Referenced standards
The provisions contained in the following standards constitute the provisions of this standard through reference in this standard. When this standard is published, the versions shown are valid. All standards will be revised, and parties using this standard should explore the possibility of using the latest versions of the following standards. GB/T4074.1—1999 Winding wire test method Part 1: General provisions (idtIEC60851-11996) 3 Test method 5: Resistance
Resistance is the DC resistance of 1m long winding wire at 20℃. The measurement accuracy of the test method used is 0.5%. If it is a bundled wire, its length should not exceed 10m. Both ends should be soldered before measurement. If the resistance is measured to check whether the number of broken strands exceeds, a 10m long bundled wire should be used. If the resistance R is measured at temperature t instead of 20℃, the resistance R20 at 20℃ can be converted as follows: Rt
1+a(t-20)
Where: t——actual temperature at the time of measurement, ℃; a—temperature coefficient.
Within the temperature range of 15℃～25℃, the temperature coefficient used shall be: - copper: 020=3.96×10-8K-1;
- aluminum: 020-4.07X10-3K-1.
Perform a test. The resistance shall be recorded.
4 Test method 13: Breakdown voltage
4.1 Test principle
Approved by the State Administration of Quality and Technical Supervision on 1999-11-11, implemented on 2000-05-01
GB/T4074.5—1999
The test voltage shall be an AC voltage with a nominal frequency of 50Hz or 60Hz. Apply the test voltage from zero and then increase the voltage at a constant rate as specified in Table 1.
Table 1 Test voltage ramp-up rate
Breakdown voltage, V
4.2 Test equipment
The following test equipment shall be used:
and below
Ramp-up rate
A test transformer with a rated power of at least 500VA. Under test conditions, it can output an AC voltage with a nearly sinusoidal waveform and a peak factor of V2 ± 5% (1.34 ~ 1.48), and its capacity can ensure that the maximum voltage drop when the output current is 5mA is 2%; a leakage current detection circuit, which operates when the current reaches 5mA and above; a test voltage device that can constantly increase the voltage at a specified speed; a forced ventilation oven;
A polished metal cylinder with a diameter of 25mm. Axially mounted horizontally (see Figure 1) and electrically connected to a terminal of the test power supply; a twisting device as shown in Figure 2. It can twist two enameled wire samples with a length of 125mm; a container containing stainless steel beads or nickel-plated iron beads. The diameter of the metal beads shall not exceed 2mm. Clean the metal beads regularly by appropriate methods. 4.3 Enameled round wire with conductor nominal diameter of 0.100 mm or less Remove the insulation at one end of a straightened enameled wire sample, connect it to the upper terminal as shown in Figure 1, and then wrap it around the metal cylinder. Apply a load in accordance with Table 2 to the lower end of the enameled wire to keep the sample in close contact with the metal cylinder. Apply the test voltage between the enameled wire conductor and the metal cylinder in accordance with Section 4.1. The test should be carried out at room temperature. Measure 5 samples. Record 5 breakdown voltage values. 4.4 Enameled round wire with conductor nominal diameter of 0.100 mm or more and 2.500 mm or less 4.4.1 Test at room temperature
Remove the insulation at both ends of an enameled wire sample about 400 mm long, fold it in half, and twist it into a (125 ± 5) mm wire pair on the twisting machine shown in Figure 2. The force applied to the wire pair during twisting and the number of twists should comply with the provisions of Table 3. The end ring of the twisted part should be cut off at two places so that the distance between the ends at the cut is the largest. The ends can be bent to make the distance between them appropriate, but excessive bending or damage to the paint film should be avoided. Apply the test voltage between the two conductors of the enameled wire according to Article 4.1. Measure 5 samples. Record 5 breakdown voltage values. 4.4.2 Test at high temperature
The samples prepared according to Article 4.4.1 are placed in an oven preheated to the specified test temperature ± 3°C. After the samples are placed for at least 15 minutes, apply the test voltage between the two conductors of the enameled wire according to Article 4.1. The test should be completed within 30 minutes. Measure 5 samples. Record 5 breakdown voltage values. 2
Conductor nominal diameter, mm
and below
GB/T4074.5—1999
Load applied to enameled wire
Conductor nominal diameter, mm
Table 3 Force and number of twists applied to wire pairs
Conductor nominal diameter, mm
and below
4.5 Round wire with conductor nominal diameter of 2.500 mm or more 4.5.1 Test at room temperature
and below
A straightened specimen of about 350 mm in length is stripped of insulation at one end and then bent on a round bar as shown in Figure 3. The diameter of the round bar should be 50 mm.
Number of twists
The specimen should be placed in a container surrounded by a metal bead of at least 5 mm thickness. The end of the specimen should extend long enough to avoid flashover. Gently pour the metal beads into the container until the sample is covered with at least 90 mm of metal beads. The diameter of the metal beads should not exceed 2 mm. Stainless steel beads, nickel beads or nickel-plated iron beads are more suitable. The metal beads should be cleaned regularly with a suitable solvent, such as 1,1,1-trichloroethane. According to Section 4.1. Apply test voltage between conductor and metal bead. Note: If agreed by both parties, the test can be carried out in oil. Measure 5 samples. Record 5 breakdown voltage values. 4.5.2 Test at high temperature
Preheat the sample prepared in accordance with Article 4.5.1 in an oven to the specified test temperature ± 3°C. After the sample has been placed in the oven for at least 15 minutes, apply test voltage between conductor and metal bead in accordance with Article 4.1. The test should be completed within 30 minutes. Measure 5 samples. Record 5 breakdown voltage values. 4.6 Flat wire
4.6.1 Test at room temperature
Instructions for use:
1] The original text 5mm is wrong.
GB/T4074.5—1999
A straightened sample of about 350mm in length is removed from one end of the insulation and then bent on the round bar with the wide side as shown in Figure 3. Round rod diameter: 25mm for a nominal narrow side dimension of 2.500mm and below; 50mm for a nominal narrow side dimension of more than 2.500mm. The specimen shall be placed in a container surrounded by a metal bead of at least 5mm thickness. The ends of the specimen shall extend sufficiently to avoid flashover. Apply the test voltage between the conductor and the metal bead in accordance with Article 4.1. Note: If agreed upon by the supplier and the buyer, the test may be carried out in oil. Measure 5 specimens. Record 5 breakdown voltage values. 4.6.2 Test at high temperature
The specimen prepared in accordance with Article 4.6.1 is placed in an oven preheated to the specified test temperature ± 3°C. After the specimen has been placed for at least 15 minutes, apply the test voltage between the conductor and the metal bead in accordance with Article 4.1. The test shall be completed within 30 minutes. Measure 5 specimens. Record 5 breakdown voltage values. 5 Test method 14: Continuity of paint film (applicable to enameled round wire and film-wound round wire) The continuity of paint film is expressed by the number of pinholes detected by the unit length of winding wire through the electrical test circuit. 5.1 Low-voltage continuity test (conductor nominal diameter 0.050mm and below) The sample passes between two felts at a speed of (275±25)mm/s. The felt should be immersed in a sodium sulfate electrolyte solution with a concentration of 30g/L, and the sample conductor and the electrolyte solution are connected to the electrical circuit. Its open-circuit DC output voltage is (50±3)V (see Figure 4). The force applied to the sample should not exceed 0.03N. The number of pinholes should be measured using a suitable relay with a counter. If the insulation resistance of the sample is less than 10k2 within 0.04s, the counter should operate. When the insulation resistance of the sample is equal to 15kQ or greater, the counter should not operate. The number of pinholes indicated should not be greater than 10 per second. Continuous pinholes should be displayed by an indicator light. Perform a test. Record the number of pinholes per 30m long sample. 5.2 High-voltage continuity test (conductor nominal diameter 0.050mm or more and 1.600mm or less) 5.2.1 Test principle
A conductor grounded enameled wire sample passes through a V-groove electrode (guide wheel) at a constant speed. Apply a DC test voltage between the electrode and the ground. Detect the pinholes on the sample paint film and count them with a counter. The test results are expressed as the number of pinholes per 30m. 5.2.2 Test equipment
The following test equipment should be used:
A high-voltage power supply. It can output a filtered smooth DC voltage. Its open-circuit test voltage can be adjusted between 350V and 2000V. The short-circuit current at any test voltage is (25±5)μA. If the resistance at the pinhole is 50MQ, the voltage drop should not exceed 75%: A pinhole detection circuit. When the short-circuit current reaches the value specified in Table 4, the circuit will operate. Its response speed is (5±1)ms. If it is a bare wire specimen, the pinhole counter shall have a repetitive counting frequency of (500 ± 25) times per minute; one or two high-voltage electrode guide wheels. Made of stainless steel, as shown in Figure 5. The contact length of each electrode guide wheel with the specimen is 252.6mm
- High-voltage electrode guide wheel as shown in Figure 6. Made of stainless steel, the contact length with the specimen is 25mm to 30mm;- Grounding guide wheel as shown in Figures 5 and 6. The size is the same as the electrode guide wheel and is installed according to the respective figures.- 4.7MQ ± 10% pulse damping resistor. Connected to the high-voltage line. Note: The grounding insulation of the high-voltage electrode shall be a non-hygroscopic, non-leaking and easy-to-clean high-resistivity material. Its insulation spacing shall be able to withstand a continuous voltage of 3000V. Since the minimum capacitance to ground is required during the switching and counting process, the high-voltage lead should not be shielded. The drive motor shall be a brushless type with sufficient power to achieve the required traction speed for the 1.600mm specimen. 4
5.2.3 Test procedure
Test voltage (DC)
GB/T4074.5—1999
Table 4 Short-circuit current
Short-circuit current
The sample passes through the high-voltage electrode wheel at a speed of (275±25) mm/s. The sample conductor and electrode are connected to the electrical circuit. Its open-circuit DC test voltage is adjusted to the specified value in Table 5, with a deviation of ±5%. The grounding conductor of the sample should be connected to the positive pole. Table 5 Test voltage
Conductor type
5.2.4 Test results
Conductor nominal diameter, mm
and below
One test is performed. Record the number of pinholes per 30m of enameled wire. 6 Test method 19: Dielectric loss factor (applicable to enameled wire and bundled wire) 6.1 Test principle
DC voltage, V
Take an enameled wire sample as a capacitor, with its paint film as the dielectric, the conductor as one electrode of the capacitor, and the conductive medium as the other electrode. Connect the capacitor to a circuit that can measure the capacitance component and the resistance component at a specified frequency, thereby measuring the dielectric loss factor. 6.2 Test equipment
The following test equipment should be used:
An impedance tester. Operate at the frequency specified in the relevant product standard. Within the capacitance range required by the sample at this frequency, the capacitance measurement accuracy is ±1%;
Frequency generator. Can output sinusoidal voltage at the frequency specified in the relevant product standard; Metal tank as shown in Figure 7. Contains suitable liquid metal (alloy) and has a heating system that can control the temperature within 1°C.
Conductive suspension;
Two metal blocks. With a heating system that can control the temperature within 1°C. 6.3 Specimen preparation
6.3.1 Metal slot electrode specimen
A straight specimen is bent into a U shape and then placed in the metal slot shown in Figure 7. 6.3.2 Conductive suspension electrode specimen
6.3.2.1 Conductor enameled round wire with a nominal diameter of 0.100 mm or less - A straight specimen with a length of (100 ± 5) mm is wound on a straight bare copper wire with a diameter of 1 mm to 2 mm and then coated with a conductive suspension, such as brushing a layer of aqueous graphite dispersion on the specimen, and then dried, for example, in a forced air oven at 100°C for 30 min.
6.3.2.2 Enameled round wire and enameled rectangular wire with a conductor nominal diameter of 0.100 mm or more A straightened specimen about 150 mm long is coated with a conductive suspension, for example, a layer of aqueous graphite dispersion is brushed on the specimen. The coating length is (100 ± 5) mm. It should then be dried, for example, in a forced-air oven at 100°C for 30 min. 6.4 Test procedure
The specimen prepared in accordance with 6.3.1 should be placed in a metal trough as shown in Figure 7. The specimen prepared in accordance with 6.3.2 should be placed between two metal blocks. The specimen is connected to the impedance meter and should be brought to the specified test temperature. The dielectric loss factor is then read directly from the impedance tester.
6.5 Test results
Measure one specimen. Record the dielectric loss factor, test frequency and test temperature. o
Testing electrical industry
1-sample; 2-insulator, 3-terminal; 4-metal cylinder0
Testing electrical industry
Figure 1. Placement of cylinder and sample for breakdown voltage test6
GB/T4074.5—1999
1-separator; 2-rotating hook; 3-sample
Figure 2. Sample twisting device for breakdown voltage test
Li Shan test sheet
Filling and filling
Dimension unit: mm
Figure 3. Sample for breakdown voltage test (sample placed in metal bead groove)5—1999
A straightened specimen of about 350 mm in length is stripped of insulation at one end and then bent on the round bar at its wide side as shown in Figure 3. Round bar diameter: 25 mm for a nominal narrow side dimension of 2.500 mm and below; 50 mm for a nominal narrow side dimension of more than 2.500 mm. The specimen shall be placed in a container surrounded by a metal bead of at least 5 mm thickness. The ends of the specimen shall extend sufficiently to avoid flashover. Apply the test voltage between the conductor and the metal bead in accordance with Section 4.1. Note that the test may be carried out in oil if agreed upon by the supplier and the purchaser. Measure 5 specimens. Record 5 breakdown voltage values. 4.6.2 Test at high temperature
The specimen prepared in accordance with Section 4.6.1 is placed in an oven preheated to the specified test temperature ± 3°C. After the specimen has been allowed to stand for at least 15 min, apply the test voltage between the conductor and the metal bead in accordance with Section 4.1. The test shall be completed within 30 min. Measure 5 specimens. Record 5 breakdown voltage values. 5 Test method 14: Continuity of paint film (applicable to enameled round wire and film-wound round wire) Continuity of paint film is expressed by the number of pinholes detected by the unit length of winding wire through the electrical test circuit. 5.1 Low-voltage continuity test (conductor nominal diameter 0.050mm and below) The sample passes between two felts at a speed of (275±25)mm/s. The felt should be immersed in a sodium sulfate electrolyte solution with a concentration of 30g/L, and the sample conductor and the electrolyte solution are connected to the electrical circuit. Its open-circuit DC output voltage is (50±3)V (see Figure 4). The force applied to the sample should not exceed 0.03N. The number of pinholes should be measured using a suitable relay with a counter. If the insulation resistance of the sample is less than 10k2 within 0.04s, the counter should operate. When the insulation resistance of the sample is equal to 15kQ or greater, the counter should not operate. The number of pinholes indicated should not exceed 10 per second. Continuous pinholes should be displayed by an indicator light. Make a test. Record the number of pinholes per 30m long sample. 5.2 High-voltage continuity test (conductor nominal diameter 0.050mm or more and 1.600mm or less) 5.2.1 Test principle
A conductor grounded enameled wire sample passes through a V-groove electrode (guide wheel) at a constant speed. Apply a DC test voltage between the electrode and the ground. Detect the pinholes on the sample paint film and count them with a counter. The test results are expressed as the number of pinholes per 30m. 5.2.2 Test equipment
The following test equipment should be used:
A high-voltage power supply. It can output a filtered smooth DC voltage. Its open-circuit test voltage can be adjusted between 350V and 2000V. The short-circuit current at any test voltage is (25±5)μA. If the resistance at the pinhole is 50MQ, the voltage drop should not exceed 75%: A pinhole detection circuit. When the short-circuit current reaches the value specified in Table 4, the circuit will operate. Its response speed is (5±1)ms. If it is a bare wire specimen, the pinhole counter shall have a repetitive counting frequency of (500 ± 25) times per minute; one or two high-voltage electrode guide wheels. Made of stainless steel, as shown in Figure 5. The contact length of each electrode guide wheel with the specimen is 252.6mm
- High-voltage electrode guide wheel as shown in Figure 6. Made of stainless steel, the contact length with the specimen is 25mm to 30mm;- Grounding guide wheel as shown in Figures 5 and 6. The size is the same as the electrode guide wheel and is installed according to the respective figures.- 4.7MQ ± 10% pulse damping resistor. Connected to the high-voltage line. Note: The grounding insulation of the high-voltage electrode shall be a non-hygroscopic, non-leaking and easy-to-clean high-resistivity material. Its insulation spacing shall be able to withstand a continuous voltage of 3000V. Since the minimum capacitance to ground is required during the switching and counting process, the high-voltage lead should not be shielded. The drive motor shall be a brushless type with sufficient power to achieve the required traction speed for the 1.600mm specimen. 4
5.2.3 Test procedure
Test voltage (DC)
GB/T4074.5—1999
Table 4 Short-circuit current
Short-circuit current
The sample passes through the high-voltage electrode wheel at a speed of (275±25) mm/s. The sample conductor and electrode are connected to the electrical circuit. Its open-circuit DC test voltage is adjusted to the specified value in Table 5, with a deviation of ±5%. The grounding conductor of the sample should be connected to the positive pole. Table 5 Test voltage
Conductor type
5.2.4 Test results
Conductor nominal diameter, mm
and below
One test is performed. Record the number of pinholes per 30m of enameled wire. 6 Test method 19: Dielectric loss factor (applicable to enameled wire and bundled wire) 6.1 Test principle
DC voltage, V
Take an enameled wire sample as a capacitor, with its paint film as the dielectric, the conductor as one electrode of the capacitor, and the conductive medium as the other electrode. Connect the capacitor to a circuit that can measure the capacitance component and the resistance component at a specified frequency, thereby measuring the dielectric loss factor. 6.2 Test equipment
The following test equipment should be used:
An impedance tester. Operate at the frequency specified in the relevant product standard. Within the capacitance range required by the sample at this frequency, the capacitance measurement accuracy is ±1%;
Frequency generator. Can output sinusoidal voltage at the frequency specified in the relevant product standard; Metal tank as shown in Figure 7. Contains suitable liquid metal (alloy) and has a heating system that can control the temperature within 1°C.
Conductive suspension;
Two metal blocks. With a heating system that can control the temperature within 1°C. 6.3 Specimen preparation
6.3.1 Metal slot electrode specimen
A straight specimen is bent into a U shape and then placed in the metal slot shown in Figure 7. 6.3.2 Conductive suspension electrode specimen
6.3.2.1 Conductor enameled round wire with a nominal diameter of 0.100 mm or less - A straight specimen with a length of (100 ± 5) mm is wound on a straight bare copper wire with a diameter of 1 mm to 2 mm and then coated with a conductive suspension, such as brushing a layer of aqueous graphite dispersion on the specimen, and then dried, for example, in a forced air oven at 100°C for 30 min.
6.3.2.2 Enameled round wire and enameled rectangular wire with a conductor nominal diameter of 0.100 mm or more A straightened specimen about 150 mm long is coated with a conductive suspension, for example, a layer of aqueous graphite dispersion is brushed on the specimen. The coating length is (100 ± 5) mm. It should then be dried, for example, in a forced-air oven at 100°C for 30 min. 6.4 Test procedure
The specimen prepared in accordance with 6.3.1 should be placed in a metal trough as shown in Figure 7. The specimen prepared in accordance with 6.3.2 should be placed between two metal blocks. The specimen is connected to the impedance meter and should be brought to the specified test temperature. The dielectric loss factor is then read directly from the impedance tester.
6.5 Test results
Measure one specimen. Record the dielectric loss factor, test frequency and test temperature. o
Testing electrical industry
1-sample; 2-insulator, 3-terminal; 4-metal cylinder0
Testing electrical industry
Figure 1. Placement of cylinder and sample for breakdown voltage test6
GB/T4074.5—1999
1-separator; 2-rotating hook; 3-sample
Figure 2. Sample twisting device for breakdown voltage test
Li Shan test sheet
Filling and filling
Dimension unit: mm
Figure 3. Sample for breakdown voltage test (sample placed in metal bead groove)5—1999
A straightened specimen of about 350 mm in length is stripped of insulation at one end and then bent on the round bar at its wide side as shown in Figure 3. Round bar diameter: 25 mm for a nominal narrow side dimension of 2.500 mm and below; 50 mm for a nominal narrow side dimension of more than 2.500 mm. The specimen shall be placed in a container surrounded by a metal bead of at least 5 mm thickness. The ends of the specimen shall extend sufficiently to avoid flashover. Apply the test voltage between the conductor and the metal bead in accordance with Section 4.1. Note that the test may be carried out in oil if agreed upon by the supplier and the purchaser. Measure 5 specimens. Record 5 breakdown voltage values. 4.6.2 Test at high temperature
The specimen prepared in accordance with Section 4.6.1 is placed in an oven preheated to the specified test temperature ± 3°C. After the specimen has been allowed to stand for at least 15 min, apply the test voltage between the conductor and the metal bead in accordance with Section 4.1. The test shall be completed within 30 min. Measure 5 specimens. Record 5 breakdown voltage values. 5 Test method 14: Continuity of paint film (applicable to enameled round wire and film-wound round wire) Continuity of paint film is expressed by the number of pinholes detected by the unit length of winding wire through the electrical test circuit. 5.1 Low-voltage continuity test (conductor nominal diameter 0.050mm and below) The sample passes between two felts at a speed of (275±25)mm/s. The felt should be immersed in a sodium sulfate electrolyte solution with a concentration of 30g/L, and the sample conductor and the electrolyte solution are connected to the electrical circuit. Its open-circuit DC output voltage is (50±3)V (see Figure 4). The force applied to the sample should not exceed 0.03N. The number of pinholes should be measured using a suitable relay with a counter. If the insulation resistance of the sample is less than 10k2 within 0.04s, the counter should operate. When the insulation resistance of the sample is equal to 15kQ or greater, the counter should not operate. The number of pinholes indicated should not exceed 10 per second. Continuous pinholes should be displayed by an indicator light. Make a test. Record the number of pinholes per 30m long sample. 5.2 High-voltage continuity test (conductor nominal diameter 0.050mm or more and 1.600mm or less) 5.2.1 Test principle
A conductor grounded enameled wire sample passes through a V-groove electrode (guide wheel) at a constant speed. Apply a DC test voltage between the electrode and the ground. Detect the pinholes on the sample paint film and count them with a counter. The test results are expressed as the number of pinholes per 30m. 5.2.2 Test equipment
The following test equipment should be used:
A high-voltage power supply. It can output a filtered smooth DC voltage. Its open-circuit test voltage can be adjusted between 350V and 2000V. The short-circuit current at any test voltage is (25±5)μA. If the resistance at the pinhole is 50MQ, the voltage drop should not exceed 75%: A pinhole detection circuit. When the short-circuit current reaches the value specified in Table 4, the circuit will operate. Its response speed is (5±1)ms. If it is a bare wire specimen, the pinhole counter shall have a repetitive counting frequency of (500 ± 25) times per minute; one or two high-voltage electrode guide wheels. Made of stainless steel, as shown in Figure 5. The contact length of each electrode guide wheel with the specimen is 252.6mm
- High-voltage electrode guide wheel as shown in Figure 6. Made of stainless steel, the contact length with the specimen is 25mm to 30mm;- Grounding guide wheel as shown in Figures 5 and 6. The size is the same as the electrode guide wheel and is installed according to the respective figures.- 4.7MQ ± 10% pulse damping resistor. Connected to the high-voltage line. Note: The grounding insulation of the high-voltage electrode shall be a non-hygroscopic, non-leaking and easy-to-clean high-resistivity material. Its insulation spacing shall be able to withstand a continuous voltage of 3000V. Since the minimum capacitance to ground is required during the switching and counting process, the high-voltage lead should not be shielded. The drive motor shall be a brushless type with sufficient power to achieve the required traction speed for the 1.600mm specimen. 4
5.2.3 Test procedure
Test voltage (DC)
GB/T4074.5—1999
Table 4 Short-circuit current
Short-circuit current
The sample passes through the high-voltage electrode wheel at a speed of (275±25) mm/s. The sample conductor and electrode are connected to the electrical circuit. Its open-circuit DC test voltage is adjusted to the specified value in Table 5, with a deviation of ±5%. The grounding conductor of the sample should be connected to the positive pole. Table 5 Test voltage
Conductor type
5.2.4 Test results
Conductor nominal diameter, mm
and below
One test is performed. Record the number of pinholes per 30m of enameled wire. 6 Test method 19: Dielectric loss factor (applicable to enameled wire and bundled wire) 6.1 Test principle
DC voltage, V
Take an enameled wire sample as a capacitor, with its paint film as the dielectric, the conductor as one electrode of the capacitor, and the conductive medium as the other electrode. Connect the capacitor to a circuit that can measure the capacitance component and the resistance component at a specified frequency, thereby measuring the dielectric loss factor. 6.2 Test equipment
The following test equipment should be used:
An impedance tester. Operate at the frequency specified in the relevant product standard. Within the capacitance range required by the sample at this frequency, the capacitance measurement accuracy is ±1%;
Frequency generator. Can output sinusoidal voltage at the frequency specified in the relevant product standard; Metal tank as shown in Figure 7. Contains suitable liquid metal (alloy) and has a heating system that can control the temperature within 1°C.
Conductive suspension;
Two metal blocks. With a heating system that can control the temperature within 1°C. 6.3 Specimen preparation
6.3.1 Metal slot electrode specimen
A straight specimen is bent into a U shape and then placed in the metal slot shown in Figure 7. 6.3.2 Conductive suspension electrode specimen
6.3.2.1 Conductor enameled round wire with a nominal diameter of 0.100 mm or less - A straight specimen with a length of (100 ± 5) mm is wound on a straight bare copper wire with a diameter of 1 mm to 2 mm and then coated with a conductive suspension, such as brushing a layer of aqueous graphite dispersion on the specimen, and then dried, for example, in a forced air oven at 100°C for 30 min.
6.3.2.2 Enameled round wire and enameled rectangular wire with a conductor nominal diameter of 0.100 mm or more A straightened specimen about 150 mm long is coated with a conductive suspension, for example, a layer of aqueous graphite dispersion is brushed on the specimen. The coating length is (100 ± 5) mm. It should then be dried, for example, in a forced-air oven at 100°C for 30 min. 6.4 Test procedure
The specimen prepared in accordance with 6.3.1 should be placed in a metal trough as shown in Figure 7. The specimen prepared in accordance with 6.3.2 should be placed between two metal blocks. The specimen is connected to the impedance meter and should be brought to the specified test temperature. The dielectric loss factor is then read directly from the impedance tester.
6.5 Test results
Measure one specimen. Record the dielectric loss factor, test frequency and test temperature. o
Testing electrical industry
1-sample; 2-insulator, 3-terminal; 4-metal cylinder0
Testing electrical industry
Figure 1. Placement of cylinder and sample for breakdown voltage test6
GB/T4074.5—1999
1-separator; 2-rotating hook; 3-sample
Figure 2. Sample twisting device for breakdown voltage test
Li Shan test sheet
Filling and filling
Dimension unit: mm
Figure 3. Sample for breakdown voltage test (sample placed in metal bead groove)The sample (050mm and below) passes between two felts at a speed of (275±25)mm/s. The felt should be immersed in a sodium sulfate electrolyte solution with a concentration of 30g/L, and the sample conductor and the electrolyte solution are connected to the electrical circuit. Its open circuit DC output voltage is (50±3)V (see Figure 4). The force applied to the sample should not exceed 0.03N. The number of pinholes should be measured using a suitable relay with a counter. If the insulation resistance of the sample is less than 10k2 within 0.04s, the counter should operate. When the insulation resistance of the sample is equal to 15kQ or greater, the counter should not operate. The number of pinholes indicated should not be greater than 10 per second. Continuous pinholes should be displayed by an indicator light. Do a test. Record the number of pinholes for every 30m long sample. 5.2 High-voltage continuity test (conductor nominal diameter 0.050mm or more and 1.600mm or less) 5.2.1 Test principle
A conductor grounded enameled wire sample passes through a V-groove electrode (guide wheel) at a constant speed. A DC test voltage is applied between the electrode and the ground. The pinholes on the sample paint film are detected and counted with a counter. The test results are expressed as the number of pinholes per 30m. 5.2.2 Test equipment
The following test equipment should be used:
A high-voltage power supply. It can output a filtered smooth DC voltage. Its open-circuit test voltage can be adjusted between 350V and 2000V. The short-circuit current at any test voltage is (25±5)μA. If the resistance at the pinhole is 50MQ, the voltage drop should not exceed 75%: A pinhole detection circuit. When the short-circuit current reaches the value specified in Table 4, the circuit operates. Its response speed is (5±1)ms. If it is a bare wire specimen, the pinhole counter shall have a repetitive counting frequency of (500 ± 25) times per minute; one or two high-voltage electrode guide wheels. Made of stainless steel, as shown in Figure 5. The contact length of each electrode guide wheel with the specimen is 252.6mm
- High-voltage electrode guide wheel as shown in Figure 6. Made of stainless steel, the contact length with the specimen is 25mm to 30mm;- Grounding guide wheel as shown in Figures 5 and 6. The size is the same as the electrode guide wheel and is installed according to the respective figures.- 4.7MQ ± 10% pulse damping resistor. Connected to the high-voltage line. Note: The grounding insulation of the high-voltage electrode shall be a non-hygroscopic, non-leaking and easy-to-clean high-resistivity material. Its insulation spacing shall be able to withstand a continuous voltage of 3000V. Since the minimum capacitance to ground is required during the switching and counting process, the high-voltage lead should not be shielded. The drive motor shall be a brushless type with sufficient power to achieve the required traction speed for the 1.600mm specimen. 4
5.2.3 Test procedure
Test voltage (DC)
GB/T4074.5—1999
Table 4 Short-circuit current
Short-circuit current
The sample passes through the high-voltage electrode wheel at a speed of (275±25) mm/s. The sample conductor and electrode are connected to the electrical circuit. Its open-circuit DC test voltage is adjusted to the specified value in Table 5, with a deviation of ±5%. The grounding conductor of the sample should be connected to the positive pole. Table 5 Test voltage
Conductor type
5.2.4 Test results
Conductor nominal diameter, mm
and below
One test is performed. Record the number of pinholes per 30m of enameled wire. 6 Test method 19: Dielectric loss factor (applicable to enameled wire and bundled wire) 6.1 Test principle
DC voltage, V
Take an enameled wire sample as a capacitor, with its paint film as the dielectric, the conductor as one electrode of the capacitor, and the conductive medium as the other electrode. Connect the capacitor to a circuit that can measure the capacitance component and the resistance component at a specified frequency, thereby measuring the dielectric loss factor. 6.2 Test equipment
The following test equipment should be used:
An impedance tester. Operate at the frequency specified in the relevant product standard. Within the capacitance range required by the sample at this frequency, the capacitance measurement accuracy is ±1%;
Frequency generator. Can output sinusoidal voltage at the frequency specified in the relevant product standard; Metal tank as shown in Figure 7. Contains suitable liquid metal (alloy) and has a heating system that can control the temperature within 1°C.
Conductive suspension;
Two metal blocks. With a heating system that can control the temperature within 1°C. 6.3 Specimen preparation
6.3.1 Metal slot electrode specimen
A straight specimen is bent into a U shape and then placed in the metal slot shown in Figure 7. 6.3.2 Conductive suspension electrode specimen
6.3.2.1 Conductor enameled round wire with a nominal diameter of 0.100 mm or less - A straight specimen with a length of (100 ± 5) mm is wound on a straight bare copper wire with a diameter of 1 mm to 2 mm and then coated with a conductive suspension, such as brushing a layer of aqueous graphite dispersion on the specimen, and then dried, for example, in a forced air oven at 100°C for 30 min.
6.3.2.2 Enameled round wire and enameled rectangular wire with a conductor nominal diameter of 0.100 mm or more A straightened specimen about 150 mm long is coated with a conductive suspension, for example, a layer of aqueous graphite dispersion is brushed on the specimen. The coating length is (100 ± 5) mm. It should then be dried, for example, in a forced-air oven at 100°C for 30 min. 6.4 Test procedure
The specimen prepared in accordance with 6.3.1 should be placed in a metal trough as shown in Figure 7. The specimen prepared in accordance with 6.3.2 should be placed between two metal blocks. The specimen is connected to the impedance meter and should be brought to the specified test temperature. The dielectric loss factor is then read directly from the impedance tester.
6.5 Test results
Measure one specimen. Record the dielectric loss factor, test frequency and test temperature. o
Testing electrical industry
1-sample; 2-insulator, 3-terminal; 4-metal cylinder0
Testing electrical industry
Figure 1. Placement of cylinder and sample for breakdown voltage test6
GB/T4074.5—1999
1-separator; 2-rotating hook; 3-sample
Figure 2. Sample twisting device for breakdown voltage test
Li Shan test sheet
Filling and filling
Dimension unit: mm
Figure 3. Sample for breakdown voltage test (sample placed in metal bead groove)The sample (050mm and below) passes between two felts at a speed of (275±25)mm/s. The felt should be immersed in a sodium sulfate electrolyte solution with a concentration of 30g/L, and the sample conductor and the electrolyte solution are connected to the electrical circuit. Its open circuit DC output voltage is (50±3)V (see Figure 4). The force applied to the sample should not exceed 0.03N. The number of pinholes should be measured using a suitable relay with a counter. If the insulation resistance of the sample is less than 10k2 within 0.04s, the counter should operate. When the insulation resistance of the sample is equal to 15kQ or greater, the counter should not operate. The number of pinholes indicated should not be greater than 10 per second. Continuous pinholes should be displayed by an indicator light. Do a test. Record the number of pinholes for every 30m long sample. 5.2 High-voltage continuity test (conductor nominal diameter 0.050mm or more and 1.600mm or less) 5.2.1 Test principle
A conductor grounded enameled wire sample passes through a V-groove electrode (guide wheel) at a constant speed. A DC test voltage is applied between the electrode and the ground. The pinholes on the sample paint film are detected and counted with a counter. The test results are expressed as the number of pinholes per 30m. 5.2.2 Test equipment
The following test equipment should be used:
A high-voltage power supply. It can output a filtered smooth DC voltage. Its open-circuit test voltage can be adjusted between 350V and 2000V. The short-circuit current at any test voltage is (25±5)μA. If the resistance at the pinhole is 50MQ, the voltage drop should not exceed 75%: A pinhole detection circuit. When the short-circuit current reaches the value specified in Table 4, the circuit operates. Its response speed is (5±1)ms. If it is a bare wire specimen, the pinhole counter shall have a repetitive counting frequency of (500 ± 25) times per minute; one or two high-voltage electrode guide wheels. Made of stainless steel, as shown in Figure 5. The contact length of each electrode guide wheel with the specimen is 252.6mm
- High-voltage electrode guide wheel as shown in Figure 6. Made of stainless steel, the contact length with the specimen is 25mm to 30mm;- Grounding guide wheel as shown in Figures 5 and 6. The size is the same as the electrode guide wheel and is installed according to the respective figures.- 4.7MQ ± 10% pulse damping resistor. Connected to the high-voltage line. Note: The grounding insulation of the high-voltage electrode shall be a non-hygroscopic, non-leaking and easy-to-clean high-resistivity material. Its insulation spacing shall be able to withstand a continuous voltage of 3000V. Since the minimum capacitance to ground is required during the switching and counting process, the high-voltage lead should not be shielded. The drive motor shall be a brushless type with sufficient power to achieve the required traction speed for the 1.600mm specimen. 4bzxZ.net
5.2.3 Test procedure
Test voltage (DC)
GB/T4074.5—1999
Table 4 Short-circuit current
Short-circuit current
The sample passes through the high-voltage electrode wheel at a speed of (275±25) mm/s. The sample conductor and electrode are connected to the electrical circuit. Its open-circuit DC test voltage is adjusted to the specified value in Table 5, with a deviation of ±5%. The grounding conductor of the sample should be connected to the positive pole. Table 5 Test voltage
Conductor type
5.2.4 Test results
Conductor nominal diameter, mm
and below
One test is performed. Record the number of pinholes per 30m of enameled wire. 6 Test method 19: Dielectric loss factor (applicable to enameled wire and bundled wire) 6.1 Test principle
DC voltage, V
Take an enameled wire sample as a capacitor, with its paint film as the dielectric, the conductor as one electrode of the capacitor, and the conductive medium as the other electrode. Connect the capacitor to a circuit that can measure the capacitance component and the resistance component at a specified frequency, thereby measuring the dielectric loss factor. 6.2 Test equipment
The following test equipment should be used:
An impedance tester. Operate at the frequency specified in the relevant product standard. Within the capacitance range required by the sample at this frequency, the capacitance measurement accuracy is ±1%;
Frequency generator. Can output sinusoidal voltage at the frequency specified in the relevant product standard; Metal tank as shown in Figure 7. Contains suitable liquid metal (alloy) and has a heating system that can control the temperature within 1°C.
Conductive suspension;
Two metal blocks. With a heating system that can control the temperature within 1°C. 6.3 Specimen preparation
6.3.1 Metal slot electrode specimen
A straight specimen is bent into a U shape and then placed in the metal slot shown in Figure 7. 6.3.2 Conductive suspension electrode specimen
6.3.2.1 Conductor enameled round wire with a nominal diameter of 0.100 mm or less - A straight specimen with a length of (100 ± 5) mm is wound on a straight bare copper wire with a diameter of 1 mm to 2 mm and then coated with a conductive suspension, such as brushing a layer of aqueous graphite dispersion on the specimen, and then dried, for example, in a forced air oven at 100°C for 30 min.
6.3.2.2 Enameled round wire and enameled rectangular wire with a conductor nominal diameter of 0.100 mm or more A straightened specimen about 150 mm long is coated with a conductive suspension, for example, a layer of aqueous graphite dispersion is brushed on the specimen. The coating length is (100 ± 5) mm. It should then be dried, for example, in a forced-air oven at 100°C for 30 min. 6.4 Test procedure
The specimen prepared in accordance with 6.3.1 should be placed in a metal trough as shown in Figure 7. The specimen prepared in accordance with 6.3.2 should be placed between two metal blocks. The specimen is connected to the impedance meter and should be brought to the specified test temperature. The dielectric loss factor is then read directly from the impedance tester.
6.5 Test results
Measure one specimen. Record the dielectric loss factor, test frequency and test temperature. o
Testing electrical industry
1-sample; 2-insulator, 3-terminal; 4-metal cylinder0
Testing electrical industry
Figure 1. Placement of cylinder and sample for breakdown voltage test6
GB/T4074.5—1999
1-separator; 2-rotating hook; 3-sample
Figure 2. Sample twisting device for breakdown voltage test
Li Shan test sheet
Filling and filling
Dimension unit: mm
Figure 3. Sample for breakdown voltage test (sample placed in metal bead groove)5—1999
Table 4 Short-circuit current
Short-circuit current
The sample passes through the high-voltage electrode wheel at a speed of (275±25) mm/s. The sample conductor and electrode are connected to the electrical circuit. Its open-circuit DC test voltage is adjusted to the specified value in Table 5, with a deviation of ±5%. The grounding conductor of the sample should be connected to the positive pole. Table 5 Test voltage
Conductor type
5.2.4 Test results
Conductor nominal diameter, mm
and below
Perform a test. Record the number of pinholes per 30m of enameled wire. 6 Test method 19: Dielectric loss factor (applicable to enameled wire and bundled wire) 6.1 Test principle
DC voltage, V
Take an enameled wire sample as a capacitor, its paint film as the dielectric, the conductor as one electrode of the capacitor, and the conductive medium as the other electrode. Connect the capacitor to the circuit, which can measure the capacitance component and the resistance component at the specified frequency, and thus measure the dielectric loss factor. 6.2 Test equipment
The following test equipment should be used:
An impedance tester. Operate at the frequency specified in the relevant product standards. Within the capacitance range required by the sample at this frequency, the measurement accuracy of the capacitance is ±1%;
Frequency generator. Can output sinusoidal voltage at the frequency specified in the relevant product standards; Metal tank as shown in Figure 7. Contains suitable liquid metal (alloy) and has a heating system that can control the temperature within 1°C.
Conductive suspension;
Two metal blocks. With a heating system that can control the temperature within 1°C. 6.3 Sample preparation
6.3.1 Metal tank electrode sample
The straightened sample is bent into a U shape and then placed in the metal tank as shown in Figure 7. 6.3.2 Conductive suspension electrode specimens
6.3.2.1 Enameled round wire with a conductor nominal diameter of 0.100 mm or less - a straightened specimen of (100 ± 5) mm in length is wound on a straightened bare copper wire with a diameter of 1 mm to 2 mm, and then coated with a conductive 5
GB/T4074.5-1999
suspension, such as brushing a layer of aqueous graphite dispersion on the specimen, and then dried, for example, in a forced-air oven at 100°C for 30 min.
6.3.2.2 Enameled round wire and enameled rectangular wire with a conductor nominal diameter of more than 0.100 mm are coated with a conductive suspension on a straightened specimen of about 150 mm in length, such as brushing a layer of aqueous graphite dispersion on the specimen. The coating length is (100 ± 5) mm. Then it should be dried, for example, in a forced-air oven at 100°C for 30 min. 6.4 Test procedure
The specimen prepared in accordance with 6.3.1 shall be placed in a metal trough as shown in Figure 7. The specimen prepared in accordance with 6.3.2 shall be placed between two metal blocks. The specimen is connected to the impedance meter and shall be brought to the specified test temperature. The dielectric loss factor is then read directly from the impedance tester.
6.5 Test results
Measure one specimen. Record the dielectric loss factor, test frequency and test temperature. o
Testing electrical industry
1-sample; 2-insulator, 3-terminal; 4-metal cylinder0
Testing electrical industry
Figure 1. Placement of cylinder and sample for breakdown voltage test6
GB/T4074.5—1999
1-separator; 2-rotating hook; 3-sample
Figure 2. Sample twisting device for breakdown voltage test
Li Shan test sheet
Filling and filling
Dimension unit: mm
Figure 3. Sample for breakdown voltage test (sample placed in metal bead groove)5—1999
Table 4 Short-circuit current
Short-circuit current
The sample passes through the high-voltage electrode wheel at a speed of (275±25) mm/s. The sample conductor and electrode are connected to the electrical circuit. Its open-circuit DC test voltage is adjusted to the specified value in Table 5, with a deviation of ±5%. The grounding conductor of the sample should be connected to the positive pole. Table 5 Test voltage
Conductor type
5.2.4 Test results
Conductor nominal diameter, mm
and below
Perform a test. Record the number of pinholes per 30m of enameled wire. 6 Test method 19: Dielectric loss factor (applicable to enameled wire and bundled wire) 6.1 Test principle
DC voltage, V
Take an enameled wire sample as a capacitor, its paint film as the dielectric, the conductor as one electrode of the capacitor, and the conductive medium as the other electrode. Connect the capacitor to the circuit, which can measure the capacitance component and the resistance component at the specified frequency, and thus measure the dielectric loss factor. 6.2 Test equipment
The following test equipment should be used:
An impedance tester. Operate at the frequency specified in the relevant product standards. Within the capacitance range required by the sample at this frequency, the measurement accuracy of the capacitance is ±1%;
Frequency generator. Can output sinusoidal voltage at the frequency specified in the relevant product standards; Metal tank as shown in Figure 7. Contains suitable liquid metal (alloy) and has a heating system that can control the temperature within 1°C.
Conductive suspension;
Two metal blocks. With a heating system that can control the temperature within 1°C. 6.3 Sample preparation
6.3.1 Metal tank electrode sample
The straightened sample is bent into a U shape and then placed in the metal tank as shown in Figure 7. 6.3.2 Conductive suspension electrode specimens
6.3.2.1 Enameled round wire with a conductor nominal diameter of 0.100 mm or less - a straightened specimen of (100 ± 5) mm in length is wound on a straightened bare copper wire with a diameter of 1 mm to 2 mm, and then coated with a conductive 5
GB/T4074.5-1999
suspension, such as brushing a layer of aqueous graphite dispersion on the specimen, and then dried, for example, in a forced-air oven at 100°C for 30 min.
6.3.2.2 Enameled round wire and enameled rectangular wire with a conductor nominal diameter of more than 0.100 mm are coated with a conductive suspension on a straightened specimen of about 150 mm in length, such as brushing a layer of aqueous graphite dispersion on the specimen. The coating length is (100 ± 5) mm. Then it should be dried, for example, in a forced-air oven at 100°C for 30 min. 6.4 Test procedure
The specimen prepared in accordance with 6.3.1 shall be placed in a metal trough as shown in Figure 7. The specimen prepared in accordance with 6.3.2 shall be placed between two metal blocks. The specimen is connected to the impedance meter and shall be brought to the specified test temperature. The dielectric loss factor is then read directly from the impedance tester.
6.5 Test results
Measure one specimen. Record the dielectric loss factor, test frequency and test temperature. o
Testing electrical industry
1-sample; 2-insulator, 3-terminal; 4-metal cylinder0
Testing electrical industry
Figure 1. Placement of cylinder and sample for breakdown voltage test6
GB/T4074.5—1999
1-separator; 2-rotating hook; 3-sample
Figure 2. Sample twisting device for breakdown voltage test
Li Shan test sheet
Filling and filling
Dimension unit: mm
Figure 3. Sample for breakdown voltage test (sample placed in metal bead groove)
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