JB/T 9615.1-2000 Test method for interturn insulation of loose-fitting windings of AC low-voltage motors
Some standard content:
JB/T9615.1—2000
This standard is one of the series of standards for the inter-turn insulation test of scattered windings of AC low-voltage motors. The series consists of the following two parts: 1) JB/T9615.1—2000 Inter-turn insulation test method of scattered windings of AC low-voltage motors 2) JB/T9615.2-2000 Inter-turn insulation test limit of scattered windings of AC low-voltage motors This standard is a revision of JB/Z294—1987 "Inter-turn insulation test method of scattered windings of AC low-voltage motors" based on GB/T1.1-1993.
Compared with JB/Z294-1987, this standard has modified the standard writing format, and the technical content remains basically unchanged. Part of the content has been coordinated with JB/Z346—1989, which was revised at the same time. In order to meet the needs of automatic detection, the requirements for test instruments in Chapter 4 have been supplemented. The original standard has been implemented for more than ten years, and the typical test waveform spectrum in Appendix A has been deleted because it is familiar and no longer needs to be used as an example. This standard replaces JB/Z294-1987 from the date of implementation. Appendix A of this standard is a standard appendix, and Appendix B is a reminder appendix. This standard is proposed and managed by Shanghai Electric Science Research Institute. The drafting unit of this standard: Shanghai Electric Science Research Institute. The main drafters of this standard: Chen Hanqiu and Qin Xiaoxiao. 461
1 Scope
Machinery Industry Standard of the People's Republic of China
Test methods of the interturn insulation on random wound winding for AC low-voltage machines
Test methods of the interturn insulation on random wound winding for AC low-voltage machines This standard specifies the test methods for the interturn insulation test on random wound winding for AC low-voltage machines JB/T 9615.1---2000
Replaces JB/Z294-1987
This standard applies to the interturn insulation test of random wound windings of three-phase or single-phase AC motors with a rated voltage of 1140V and below. 2 Reference standards
The provisions contained in the following standards constitute the provisions of this standard through reference in this standard. At the time of publication of the standard, 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. JB/T9615.2--2000 Test limits for inter-turn insulation of scattered windings of AC low-voltage motors 3 Definitions
This standard adopts the following definitions.
3.1 Impulse waveform comparison method
A method for testing the inter-turn insulation of motor windings (or coils) using impulse voltage. An impulse voltage wave with a specified peak value and wavefront time is applied alternately (or simultaneously) directly to the test winding (or coil) and the reference winding (or coil) of the same design. The difference in the attenuated oscillation waveform caused by the impulse voltage between the two is used to detect whether the inter-turn insulation of the motor winding (or coil) is good. See Appendix A (Appendix to the standard) for details. 3.2 Reference winding (or coil)
When using the impulse waveform comparison method to detect the inter-turn insulation of motor windings (or coils), the motor winding (or coil) used for comparison with the test winding (or coil).
3.3 Test waveform difference
When the impulse waveform comparison method is used to detect the inter-turn insulation of the motor winding (or coil), the difference between the test waveforms in the test winding (or coil) and the reference winding (or coil) caused by inter-turn insulation faults or non-insulation faults such as material and process fluctuations is usually expressed as a percentage.
The test waveform difference caused by inter-turn insulation faults is often called harmful difference. The test waveform difference caused by non-insulation faults is often called harmless difference or allowable difference. 4 Test instrument
4.1 The two groups of impulse voltage waves output by the instrument should be symmetrical (tolerance ±: 3%). The instrument is allowed to output a single group of impulse voltage waves or convert a single group of impulse voltages into two groups of impulse voltage waves for output. Approved by the State Bureau of Machinery Industry on April 24, 2000 462
Implemented on October 7, 2000
JB/T9615.1—2000
4.2 The wavefront time of the first impulse voltage wave output by the instrument is 0.2us (tolerance: 1us) and 1.2us (tolerance ±30%), and 0.2us is preferred. Other wavefront times can also be output according to user needs. 4.3 The maximum impulse voltage peak value output by the instrument should be able to meet the test limit requirements of JB/T9615.2 for relevant test products, with a tolerance of ±5% or ±3%, and ±3% is preferred.
4.4 The impulse voltage peak value output by the instrument should be continuously adjustable, with an indication or can be preset. The measurement accuracy is ±1.5% or ±1%, and ±1% is preferred and a digital peak voltage meter is used for indication. 4.5 The instrument should be able to clearly display and distinguish waveforms, and the waveform scanning frequency is adjustable. 4.6 The instrument should be able to operate continuously and reliably.
4.7 The instrument should be equipped with a dedicated test line, a reliable grounding terminal and necessary safety warning facilities, and the test conversion wiring should be convenient and reliable. 4.8 The instrument can be equipped with a microcomputer interface and can have functions such as test waveform storage, comparison parameter setting, test waveform difference display, automatic judgment and alarm. The instrument can be equipped with a test voltage conversion test device. 5 Test method
5.1 Preparation
5.1.1 Check that the instrument casing has been reliably grounded. 5.1.2 Preset the impulse test voltage peak and wavefront time as specified in JB/T9615.2. 5.1.3 Check that the instrument test waveforms coincide. Connect the two sets of measuring wires of the instrument to the same winding (or coil) respectively, and check that the two oscillation waveforms output by the instrument should completely overlap.
5.1.4 Select the reference winding (or coil). The parameters of the reference winding (or wire diagram) (wire gauge, number of turns, winding method, connection form, etc.) should be the same as those of the test winding (or coil). For three-phase motors, the reference winding (or coil) can be selected from the windings (or coils) of the same motor, or from the windings (or coils) of motors of the same specifications. During the test, the reference winding (or coil) can be relatively fixed or rotated. It is recommended to select from the same motor and rotate in sequence.
The reference winding (or coil) can be a winding (or coil) whose turn-to-turn insulation has been confirmed to be normal or assumed to be normal. Coil). For single-phase motors, select a motor winding with intact insulation between turns: windings and to ground as a reference. 5.1.5 The core of the test piece can be properly grounded or insulated from the ground (the core is energized in this case). Whether the core of the test piece is grounded during the test will change the impedance of the test piece and affect the display of the test waveform. During the test, discharge at the poorly grounded part of the core of the test piece will interfere with the display and judgment of the test waveform. 5.2 Three-phase motor test
5.2.1Φ(phase) connection method
Select one phase winding (for example, U phase) as the reference and the other phase winding (for example, V phase) as the test piece (see Figure 1). Alternately (or simultaneously) apply impulse voltage waves with the peak value and wavefront time specified in JB/T9615.2 to the U phase and V phase, and compare the two attenuated oscillation test waveforms. The difference between them. Then switch to V phase and W phase (or U phase and W phase) and repeat the test once. After each test, the non-test winding should be discharged. U
H, H2-Instrument high potential terminal: l. ·Instrument low potential terminal Figure 1Φ (phase) connection method wiring diagram example
5.2.2Y (line) connection method
JB/T9615.1--2000
For the motor windings connected in Y, select one (two-phase series) winding (for example UW) as the reference product, and the other (two-phase series) winding (for example VW) as the test product (see Figure 2), alternately apply the impulse voltage wave with the peak value and wave front time specified in JB/T9615.2 on UW and VW, and compare the difference between the two attenuation oscillation test waveforms. Measure. Then switch the L terminal to the U (or V) terminal in turn, and repeat the test once.
H, H - instrument high potential terminal; L - instrument low potential terminal Figure 2 Y (line) connection method wiring diagram example
5.2.3△A (angle) connection method
For the motor windings that have been connected to A, select one (two-phase windings in series and the third-phase winding in parallel) winding (for example, UW) as the reference product, and the other (two-phase windings in series and the third-phase winding in parallel) winding (for example, VW) as the test product (see Figure 3), alternately apply the impulse voltage wave with the peak value and wavefront time specified in JB/T9615.2 to UW and VW, and compare the difference between the two attenuated oscillation test waveforms. Then switch the L terminal to the U (or V) terminal in turn, and repeat the test once. 5.3 Single-phase motor
On the corresponding windings (e.g. Z, Z2) of the test product and the reference product (see Figure 4), alternately apply the impulse voltage wave with the peak value and wave front time specified in JB/T9615.2, and compare the difference between the two decay oscillation test waveforms. Then, on the other corresponding windings (e.g. U,U) Repeat the test for - times.
H, H, - Instrument high potential terminal: L - Instrument low potential terminal Figure 3 △A (angle) connection method wiring diagram
H, H. - Instrument high potential terminal; L - Instrument low potential terminal Figure 4 Single-phase motor wiring diagram example
5.4 Test display and test time
5.4.1 Test display
The test waveform should be displayed on the oscilloscope screen. In automatic testing, it is allowed not to display the test waveform but only display the judgment result. 464
5.4.2 Test time
JB/T9615.1—2000
The test time shall be in accordance with the provisions of 4.3 of JB/T9615.2—2000. 6 Principles for selecting test connection methods
6.1Φ (phase) connection method
Applicable to the detection of windings with lead-out terminals at both ends of each phase, or Y-connected windings with lead-out midpoint N, or △-connected windings with untied connection points. It is also applicable to the detection of comparable unit test products such as pole phase groups or single coils of windings. Φ (phase) connection method is the basic connection method for judging inter-turn insulation faults. 6.2Y (line) connection method
Applicable to the detection of Y-connected motor windings.
Y (line) connection method can increase the impedance of the test product and expand the testable product capacity range of the test instrument. For motor windings with larger capacity, it is recommended to use the Y (line) connection method for testing.
6.3△ (angle) connection method
Applicable to the detection of motor windings that have been connected in △ connection. 7 Test judgment
This standard uses the test waveform as the main judgment basis. The test waveform automatic discrimination device that can compare and calculate the difference of the test waveform can be used as an auxiliary means of automatic discrimination. The test shows that the fault waveform is often accompanied by a discharge sound, and even discharge sparks and film to ozone (O:) can be seen. These signals can help to distinguish the fault type and locate the fault point.
7.1 Normal waveform
If the decay oscillation waveforms displayed in the two tests are basically overlapped without significant differences (referred to as overlap), it is a normal waveform without fault, that is, the insulation between turns of the tested winding is not faulty, see Appendix A (Appendix to the standard). 7.2 Fault waveform
If there is a situation that does not conform to the normal waveform, the insulation between turns of the winding is faulty, see Appendix A (Appendix to the standard) for details. 7.3 Three-phase motor fault discrimination
Three-phase motors should be judged for faults according to different wiring methods. If one of the two test waveforms shows a difference, there is a fault in the phase winding; if the two test waveforms show a difference, a third test is required.
If the waveforms of the third test overlap, there is a fault in one phase winding; if there is still a difference, it means that two or more phase windings 1 have a fault. For the second and third tests, only one connection method needs to be selected to make a judgment. 7.3.1 The examples of fault judgment of Φ (phase) connection method are shown in Table 1 (wiring is shown in Figure 1), and the rest are analogous. Table 1 Φ (phase) connection method fault judgment example
Test times
Instrument terminal wiring
Vi and W,
Waveform display 1
Fault judgment "
W phase fault
V phase fault
U phase fault
Test times
JB/T9615.1-2000
Table 1 (end)
Instrument terminal wiring
1) V waveform display overlap; ×--Waveform display is different. L
U, and V
V, and W,
V: and W,
U, and W:
Waveform display 1
2) U phase refers to the winding between the UV terminals; V phase refers to the winding between the VW terminals: W phase refers to the winding between the WU terminals. 7.3.2
For examples of fault judgment of Y (line) connection method, see Table 2 (wiring see Figure 2), and the rest are analogous. Table 2 Examples of fault judgment of Y (line) connection method
Test times
Instrument terminal wiring
1) V waveform display overlaps; ×-.·The waveform display is different L
Waveform display 1
2) U phase refers to the winding between the UV terminals; V phase refers to the winding between the VW terminals; W phase refers to the winding between the WU terminals. 7.3.3For examples of fault judgment of △A (angle) connection method, see Table 3 (wiring See Figure 3), and the rest is analogous. 466
Fault judgment 2
Do the third test
U phase fault
Two phases or more faults
V phase fault
Two phases or more faults
Fault judgment*
W phase faultbzxz.net
U phase fault
V phase fault
Do the third test
V phase fault
Two phases or more faults
U phase fault
Two phases or more faults
Table 3 △ (angle) connection fault judgment example
JB/T9615.1-2000
Instrument Terminal wiring
Test times
Fault discrimination? :
Waveform display"
U phase fault
W phase fault
Do the third test
Two phases and above fault
W phase fault
Two phases and above fault
Do the third test
V phase fault
V phase fault
8.2 When the test waveform difference of the tested motor winding exceeds the set value, the instrument alarms and indicates, that is, the turns of the winding are automatically judged. 8.1 For motor windings produced continuously in large quantities, it is recommended to use test voltage conversion test devices and automatic discrimination alarm devices. The automatic discrimination alarm device should be able to calculate, compare and indicate the difference of the test waveform, and can set the automatic discrimination alarm range. The conversion test device shall comply with the test conversion requirements of 5.2~5.3 of this standard and 4.4 of JB/T9615.22000. When there is any objection to the automatic judgment alarm result, the direct judgment shall be based on the test waveform according to the requirements of Chapter 7 of this standard. If there is a difference in the test waveform display, the corresponding winding of the tested motor has a fault. Waveform display overlap: ×--There is a difference in the waveform display 7.4 Single-phase motor fault judgment
automatic test and automatic judgment
automatic test, it is allowed to display only the judgment result without displaying the test waveform. There is a fault in the insulation between the two phases.
A1 Basic principle
JB/T9615.1·2000
Appendix A
(Appendix of the standard)
Impact waveform comparison method
An impulse voltage wave with specified peak value and wavefront time is applied alternately (or simultaneously) directly to the test winding (or coil) and the reference winding (or coil) of the same design. The difference in the attenuated oscillation waveform caused by the impulse voltage between the two is used to detect whether the insulation of the motor winding (or coil) is good. For motor windings of the same design, the design values of R, I, and ( of each phase winding should usually be symmetrical and balanced. If a fault such as inter-turn short circuit occurs in the winding, the winding impedance will change. When the impulse voltage wave invades the winding, an attenuated oscillation will be formed in the winding. Its oscillation frequency is: 1
2 yuan VIC
Where: impulse wave attenuation oscillation frequency, Hz; I. winding inductance, H;
C winding capacitance, F. The attenuation state is related to the Q value of the winding (or coil) (see Figure A1) . Figure A1
（A1）
Alternately input impulse voltage waves into the reference product and the test product windings, and compare whether the attenuated oscillation waveforms overlap! Whether the insulation between the winding turns is good or not can be judged.
Since the probability of insulation faults with exactly the same fault location and fault degree occurring in the reference product and the test product at the same time is very small, the test product and the reference product in the comparison test can be optional. Even if exactly the same insulation faults occur at the same time, they can be judged by appropriately changing the test product wiring.
A2 Turn-to-turn insulation fault-free waveform display
For motor windings with no turn-to-turn insulation fault, the attenuation oscillation waveforms of the impulse voltage wave in the reference product and the test product should be completely overlapped. However, due to fluctuations in materials and processing technology, a small change in winding impedance is often caused. Therefore, the attenuation oscillation waveforms in the reference product and the test product are actually just basically overlapped without significant differences (referred to as overlap). There may also be special faults when the test waveforms overlap, see A3.2 and A4.2. 468
A3 Waveform of turn-to-turn insulation fault Display
JB/T9615.1—2000
A3.1 The defects (weak points or damaged points) of the inter-turn insulation of the winding will be broken down under a certain impulse voltage to form an inter-turn short circuit. At this time, the comparison test waveform shows that there will be differences in time (cycle), amplitude and area, and the degree of difference varies with the degree and location of the fault. When the inter-turn insulation is broken down, it is sometimes accompanied by discharge sparks and discharge sounds. The test waveform shows discharge burrs and jumps, which can be used as an auxiliary section for the judgment of inter-turn insulation faults.
A3.2 For the Y and △ connection methods, when there is a common part of the comparison circuit for the inter-turn insulation fault, the attenuation oscillation waveforms of the impulse voltage wave in the reference and test windings will also overlap, but they are different from the waveforms without faults in terms of time (period), amplitude and area. A4 Waveform display of other winding faults
In addition to the inter-turn insulation short circuit, when the winding has faults such as wrong connection and wrong insertion, the winding impedance will also change. During the comparison test, the attenuation oscillation waveform will also change.
A4.1 For asymmetric faults such as partial misconnection and misinsertion, the test waveforms show differences during the comparison test, and the degree of difference varies with the degree of misconnection or misinsertion. Sometimes it is very similar to the waveform of the inter-turn insulation fault, but the discharge phenomenon is particularly evident. A4.2 All phase windings are connected or misinserted in the same way, and their impedance is balanced and symmetrical. During the comparison test, the two test waveforms overlap, but their oscillation frequency changes, which is obviously different from the correctly connected and inserted windings. A4.3 The winding is broken and the test fails to form a loop, so the oscillation waveform cannot be displayed. Sometimes there will be discharge at the broken wire. A4.4 There is an error in the number of winding turns. Depending on the percentage of the error number to the total number of turns and the test sensitivity of the tester, there will be certain differences in the attenuation oscillation waveform display during the comparison test. A5 Waveform display of phase-to-phase and ground insulation faults Phase-to-phase and ground insulation faults can also be detected by the impulse waveform comparison method: when an impulse voltage is applied between the phases of the winding or between the winding and the core, if the insulation is not faulty, the impedance of the phase-to-phase and ground insulation is very large, and the loop cannot be formed during the test, and the impulse test waveform cannot form an oscillation. If the insulation is faulty, the impulse test waveform will show certain oscillations, accompanied by discharge sparks and discharge sounds, depending on the location of the fault, which is helpful for fault identification and location. 4169
JB/T9615.2-2000
This standard is one of the series of standards for the inter-turn insulation test of AC low-voltage motors. This series consists of the following two parts: Inter-turn insulation of scattered windings of AC low-voltage motors 1) JB/T9615.12000
Test method
2) JB/T9615.2-2000 Inter-turn insulation test limit of scattered windings of AC low-voltage motors This standard is a revision of JB/Z346--1989 "Inter-turn insulation test limit of scattered windings of AC low-voltage motors" based on GB/T1.1--1993.
Compared with J3/Z346-1989, this standard has modified the standard writing format, and the technical content remains basically unchanged. Part of the content has been coordinated with JB3/7.294--1987, which was revised at the same time. To meet the needs of automatic detection and according to the development of test technology, this standard adds two comparison parameters, test waveform area difference and test waveform difference area, to the test waveform difference quantity; the size factor K is deleted from the impulse test voltage peak calculation formula, so that the test products operating in the same power grid have the same test limit requirements; the wavefront time is adjusted according to the IEC standard requirements and still includes the original recommended value. This standard replaces JB/Z346-1989 from the date of implementation. Appendix A of this standard is the appendix of the standard.
This standard is proposed and managed by Shanghai Electric Science Research Institute. The drafting unit of this standard: Shanghai Electric Science Research Institute. The main drafters of this standard: Chen Hanqiu and Qin Xiaoxiao. 470
Tip: This standard content only shows part of the intercepted content of the complete standard. If you need the complete standard, please go to the top to download the complete standard document for free.