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GB/T 4074.21-2018 PDF English

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GB/T 4074.21-2018: Winding wires test methods - Part 21: Electrical endurance under high frequency voltage impulses
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GB/T 4074.21: Evolution and historical versions

Standard IDContents [version]USDSTEP2[PDF] deliveryName of Chinese StandardStatus
GB/T 4074.21-2018English210 Add to Cart 0-9 seconds. Auto-delivery Winding wires test methods - Part 21: Electrical endurance under high frequency voltage impulses Valid
GB/T 4074.21-1987EnglishRFQ ASK 3 days Methods of test for enamelled wires--Thermal endurance test Obsolete

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GB/T 4074.21-2018: Winding wires test methods - Part 21: Electrical endurance under high frequency voltage impulses


---This is an excerpt. Full copy of true-PDF in English version (including equations, symbols, images, flow-chart, tables, and figures etc.), auto-downloaded/delivered in 9 seconds, can be purchased online: https://www.ChineseStandard.net/PDF.aspx/GBT4074.21-2018
NATIONAL STANDARD OF THE PEOPLE’S REPUBLIC OF CHINA ICS 29.060.10 K 12 Winding wires test methods - Part 21.Electrical endurance under high frequency voltage impulses Issued on. MARCH 15, 2018 Implemented on. OCTOBER 01, 2018 Issued by. General Administration of Quality Supervision, Inspection and Quarantine; Standardization Administration of PRC.

Table of Contents

Foreword... 3 1 Scope... 5 2 Normative references... 5 3 Terms and definitions... 5 4 General provisions for testing... 8 5 High frequency pulse voltage tester... 8 6 Specimen... 10 7 Test... 11 Appendix A (Informative) Method for verifying polarity of output waveform of equipment... 15 References... 18

1 Scope

This part of GB/T 4074 stipulates the test method (also known as corona resistance test method) for using high-frequency pulse voltage to determine the resistance of the winding wire to high-frequency pulse voltage in atmospheric air, including the terms and definitions of the test, test equipment, specimen preparation, test procedures, test parameters and test records. This part applies to the following winding wires. - Corona-resistant enameled round winding wire; - Grade-240 aromatic corona-resistant polyimide film wrapped sintered round and flat winding wire; - Glass fiber wrapped film winding flat winding wire; - Mica tape wrapped flat winding wire.

2 Normative references

The following documents are essential to the application of this document. For the dated documents, only the versions with the dates indicated are applicable to this document; for the undated documents, only the latest version (including all the amendments) are applicable to this standard. GB/T 4074.5-2008 Winding wires - Test methods - Part 5.Electrical properties GB/T 4074.7-2009 Winding wires - Test methods - Part 7.Test procedure for the determination of the temperature index of enameled winding wires GB/T 30435 Electric gravity convection and forced ventilation ovens

3 Terms and definitions

The following terms and definitions apply to this document. 3.1 Bipolar impulse For voltage pulses, the polarity alternates from positive to negative or from negative to positive. 3.2 Impulse-voltage repetition rate Regardless of unipolar or bipolar pulses, at the same time interval, the reciprocal of the time between two consecutive complete pulses. [IEC 62068.2013, definition 3.14] 3.5 Peak impulse voltage Up The maximum voltage value reached during the unipolar surge voltage period (see Figure 1). Note. For bipolar pulse voltage, the pulse peak voltage is half of the pulse peak-peak voltage (Upk/pk). The pulse peak-peak voltage (Upk/pk) is as shown in Figure 1. 3.6 Steady-state impulse voltage magnitude Ua The final value of the impulse voltage (see Figure 1).

4 General provisions for testing

4.1 Test principle For the test conditions and test requirements not specified in this part, they shall be carried out in accordance with the product standard. 4.2 Standard environment for specimen state conditioning and testing 4.2.1 When the test winding wire is removed from the spool, it shall neither withstand tension or unnecessary bending, nor shall it be contaminated by the outside.

5 High frequency pulse voltage tester

5.1 Composition of tester It shall include the following three parts. test power supply, timing device and hot state tester. 5.2 Test power Each specimen shall use an independent power supply during the test. The test equipment shall meet the following parameter requirements under load conditions. 5.3 Timing device Each specimen shall be timed separately. When the tested specimen is short- circuited, the timer stops counting and records the test value. 5.4 Hot state tester The electric heating oven used for the test shall meet the requirements of GB/T 30435.Room temperature ~ 200 °C, temperature deviation is ± 3 °C.

6 Specimen

6.1 Corona-resistant round winding wire 6.1.1 Product types Corona-resistant enameled round winding wire suitable for conductors which have a nominal diameter greater than 0.250 mm and less than or equal to 1.600 mm as well as the grade-240 aromatic corona-resistant polyimide film wrapped sintered round winding wire. 6.1.2 Specimen preparation For the grade-240 aromatic corona-resistant polyimide film wrapped sintered round winding wire, prepare specimen according to the provisions of 5.1.2 in GB/T 4074.7-2009. 6.1.3 Specimen screening 6.1.3.1 Grade-240 aromatic corona-resistant polyimide film wrapped sintered round winding wire 6.1.3.2 Corona-resistant enameled round winding wire For the corona-resistant enameled round winding wire, in order to ensure the uniform performance of the same batch of specimens, all specimens shall be subject to power frequency AC withstanding voltage test screening according to the voltage specified in Table 1, before the high-frequency pulse resistance test. The voltage duration is 1 s. 6.1.4 Test sample Only the samples that pass the screening of 6.1.3 power frequency AC withstanding voltage test can be subjected to the high frequency pulse test in Chapter 7. 6.2 Flat winding wire Scope of application. Glass fiber wrapped film wrapped flat winding wire, mica tape wrapped flat winding wire and grade-240 aromatic corona-resistant polyimide film wrapped sintered flat winding wire.

7 Test

7.1 Corona-resistant enameled round winding wire 7.1.1 Product types Only suitable for corona-resistant enameled round winding wires which has a paint film thickness of grade 2 and 3. 7.1.2 Main parameters of high frequency impulse voltage resistance See Table 2 for the test parameters of the corona-resistant enameled round 7.1.3 Test procedure Prepare specimen according to the provisions of 6.1 and conduct power frequency AC voltage withstanding test. 7.1.4 Test results Test 5 specimens. Record the test results. Take the minimum value and intermediate values. 7.2 Grade-240 aromatic corona-resistant polyimide film wrapped sintered round and flat winding wire 7.2.1 Main parameters of high-frequency impulse voltage resistance. See Table 4 for test parameters of grade-240 aromatic corona-resistant polyimide film wrapped sintered winding wire’s resistance to high-frequency pulse voltage. 7.3 Glass fiber film wrapped flat winding wire and mica tape wrapped flat winding wire 7.3.1 Main parameters of high-frequency pulse voltage resistance See Table 6 for the test parameters of resistance to high-frequency impulse voltage performance of glass fiber film wrapped flat winding wire and mica tape wrapped flat winding wire. 7.3.2 Test procedure Prepare specimens according to the provisions of 6.2 and conduct power frequency AC voltage withstanding test. 7.3.3 Test results Test 5 specimens. Record the test results. Take the minimum value and intermediate values. ......
Source: Above contents are excerpted from the full-copy PDF -- translated/reviewed by: www.ChineseStandard.net / Wayne Zheng et al.


      

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