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JB/T 10321-2002 Evaluation of Class B insulation structure life of series-excited motors for power tools

Basic Information

Standard ID: JB/T 10321-2002

Standard Name: Evaluation of Class B insulation structure life of series-excited motors for power tools

Chinese Name: 电动工具用串励电动机B级绝缘结构寿命的评定

Standard category:Machinery Industry Standard (JB)

state:in force

Date of Release2002-07-16

Date of Implementation:2002-12-02

standard classification number

Standard ICS number:Mechanical Manufacturing>>Handheld Tools>>25.140.20 Power Tools

Standard Classification Number:Electrical Engineering>>Electrical Equipment and Apparatus>>K64 Power Tools

associated standards

alternative situation:JB/T 5357-1991

Publication information

publishing house:Mechanical Industry Press

other information

Focal point unit:National Electric Tools Standardization Committee

Publishing department:State Economic and Trade Commission

Introduction to standards:

This standard specifies the evaluation method for the life of the B-class insulation structure of series-excited motors for electric tools under normal environmental conditions. It is used to determine the insulation structure of series-excited motors for electric tools with a temperature level of 130°C (B-class) and a single-phase AC voltage not exceeding 250V. JB/T 10321-2002 Evaluation of the life of the B-class insulation structure of series-excited motors for electric tools JB/T10321-2002 Standard download decompression password: www.bzxz.net

Some standard content:

ICS25.140.20
2002-07-16
JB/T10321—2002
2002-12-01
JB/T10321—2002
The insulation structure of single-phase series-excited motors for electric tools is a key technology to improve the safety performance and technical level of electric tools and ensure safe use. This standard is formulated on the basis of "Class B insulation structure of series-excited motors for electric tools such as electric drills and angle grinders". This standard is different in principle from GB17948.12000 (idtEC60034-18-21:1992) "Functional evaluation of insulation structure of rotating electrical machines - Test procedures for winding groups - Evaluation and classification". GB/T17948.1-2000 is formulated based on the mechanism that the aging of the insulation structure of rotating motors is caused by thermal aging, while the aging mechanism of the insulation structure of electric tools is caused by the combined effect of thermal shock and mechanical stress. The two are different in principle in terms of aging mechanism and test methods, so this standard is formulated separately. This standard is based on GBT1.1-2000 "Guidelines for Standardization.L Work Part 1: Structure and Writing Rules of Standards". This standard is proposed by the China Machinery Industry Federation. This standard is under the jurisdiction of the National Electric Tool Standardization Technical Committee. Drafting units of this standard: Shanghai Electric Tool Research Institute, Shanghai Hitachi Power Tools Co., Ltd. Drafters of this standard: Qin Yongyuan, Wu Guoqiang, Lu Shunping, Shi Meixin, Yang Muliang, Cao Hongxian, 1 Scope
JB/T10321-2Q02
Evaluation of the life of the B-level insulation structure of the series-excited motor for electric tools This standard specifies the evaluation method of the life of the B-level insulation structure of the series-excited motor for electric tools under general environmental conditions. It is used to evaluate the insulation structure of the series motor for electric tools with a temperature level of 130℃ (B-level) and a single and AC voltage not exceeding 250V (hereinafter referred to as the insulation structure). This standard is not applicable to the evaluation of the life of the insulation structure of non-series-excited motors. 2 Normative references
The clauses of the following documents become the clauses of this standard through the reference of the standard. For dated documents, all subsequent amendments (excluding errata) or revisions are not applicable to this standard. However, parties that have reached an agreement on the standard are encouraged to study whether the latest versions of these documents can be used. For undated referenced documents, the latest versions shall apply to this standard. GB/T2900.5—1983 Electrical terminology Electrical insulating materials JB/T9601-1999 Standard for the measurement accuracy of single-phase excited motors for electric tools and T.2 Specifications JB/T10254-2001 Technical requirements for stators and rotors of single-phase excited motors for electric tools 3 Terms and definitions
The following terms and definitions apply to this standard. 3.1
Insulation system
· A combination of one or more insulating materials, designed as a whole with the conductor parts according to the characteristics and size requirements of the series-excited motor for electric tools, to insulate the conductor with a potential difference. 3.2
Quality assurance test
Quality assurance test
Quality screening test to eliminate defective samples. 3.3
Service life
The insulation structure is tested according to the evaluation procedure formulated based on the operating experience and some functional test results. The time given by the sample to reach the failure standard.
Life test
The insulation structure is exposed to the combined action of predetermined temperature, electrical and mechanical stress, and the changes in certain properties are measured to evaluate the aging life of the insulation structure.
Temperature classification indicates the maximum allowable operating temperature of the insulation structure. At this temperature, it can maintain its performance within the allowable range during the predetermined service life. The temperature value corresponding to the temperature classification of Class B insulation structure is 130℃. Note: The temperature grade of this standard is the same as the temperature grade of the insulation structure of electrical products such as rotating motors and transformers, but the evaluation method is different. The temperature grade of the flameproof structure of electrical products such as rotating motors and transformers is evaluated and graded using the thermal aging method commonly used at home and abroad, while the temperature grade of the B-level insulation structure of the electric motor for electric tools is inspected and evaluated according to this standard. JB/T 10321-2002
4 General
4.1 Evaluation principle of insulation structure life
The principle of evaluating the B-level insulation structure is to simulate the aging mechanism of the insulation structure life during actual operation to evaluate the life of the B-level insulation structure. 4.2 Insulation structure operating life value
When evaluating the insulation structure life, the specimen is a rotating electric tool with a single-phase series-excited motor with a temperature grade of B-level insulation structure. The rated speed of its output shaft shall not exceed 300Cr/min; the operation shall be smooth, the dynamic balance accuracy of the rotor with fan shall not be lower than Gi6.3, and the life value of the insulation structure when it is maintained at (J25±2)℃ shall be greater than or equal to 500h: 4.3 The shrinkage material in the insulation structure
The temperature limit of the insulation structure is not completely consistent with the temperature limit of each insulating material therein. In the insulation structure, the temperature limit of the insulating material can be increased due to the expansion of other components, and the temperature limit of the insulation structure can also be lower than the temperature limit of each component material due to incompatibility between materials. Therefore, the temperature level of the insulation structure of the electric tool excitation motor is based on the temperature level evaluated by this standard, not on the temperature level of the component material itself. 4.4 Standard procedure for evaluating the life of the insulation structure a) Prepare the specimen required for the life test. b) Perform life test on the specimen according to the standard test method. c) Regularly measure the no-load current, load current and rotor temperature rise of the specimen. d) Continuously perform life test on the specimen until it exceeds the estimated service value of the life or fails. Record and organize the test data: Evaluate the temperature grade according to the test data. e
5 Test specimen
5.1 Preparation of test specimen
The test specimen used for the life test of the insulation structure is the complete electric tool, which is randomly sampled from the overall test specimens treated under the same conditions. The test specimen equipped with a thermostat should remove the thermostat. In order to ensure the smooth progress of the test, as long as the insulation structure and insulation treatment process of the test specimen remain unchanged, it is allowed to make appropriate improvements to the parts of the test specimen that are not tested, such as gears, commutators, etc. 5.2 Insulation materials and insulation treatment process
5.2.1 The name, type or model, performance, parameters, production batch number, and manufacturer of the insulation material should be recorded in detail. These insulating materials include electromagnetic wire, insulating varnish, encapsulating glue, wrapping tape, slot insulation, slot wedge, sleeve, end plate, lead wire and shaft insulation material used as additional insulation.
5.2.2 Insulation treatment process The temperature and time of insulation treatment preheating, paint dripping, gelling and curing should be recorded. 5.3 Quality of non-assessed components
To ensure the continuity and accuracy of the insulation structure test, in addition to maintaining the consistency of the quality of the sample insulation structure, it also depends on the quality of other components other than the sample insulation structure that are not assessed. The reliability of these components should be improved as much as possible. 5.4 Number of samples
This test is carried out with the whole power tool. The samples for the insulation structure life test are 5 power tools. In addition to the failure of the insulation structure, there are also other parts that are damaged, which causes the sample to fail when the insulation structure does not fail. 5 more samples are required, so the number of each sample is 10. The insulation materials and insulation treatment process in the insulation structure of each sample should be exactly the same. 5.5 Quality assurance test Before the life test, the sample stator and rotor shall be subjected to the following quality assurance tests: Appearance inspection: Dielectric strength test. Appearance inspection shall comply with the requirements of JB10254, and the dielectric strength test shall be carried out at 75% of the value required by JB/T10254. 2
6 General requirements for tests
6.1 Test method
JB/T 10321—2002
6.1.1 Test purpose and test conditions
The evaluation test is a test that simulates the influence of the actual working conditions of the electric machine on the life of the insulation structure. The sample is operated at 130°C and specified load to assess the temperature grade of the insulation structure. The test is conducted under high temperature and mechanical stress under rated voltage, thus simulating the most severe working conditions in actual operation. 6.1.2 Application of load
6.1.2.1 If the towing method is adopted, the sample is applied with rated voltage, and another generator is driven to operate as a load. The degree of the load connected in series with the generator is adjusted to reach the specified load
6.1.2.2 If water is used as a load, after the rated voltage is applied to the sample, the height of the water is adjusted to reach the specified load 6.1,3 Temperature
6.1.3.1 Temperature control
When the sample is running under the specified load, adjust the size of the air outlet to ensure that the sample is running at 130℃: the sample temperature obtained in 6.1.3.2 is the average temperature, not the highest temperature point of the sample. Therefore, the temperature of the sample is controlled at (125 ± 2) (6.1.3.2 Temperature rise measurement
The temperature rise of the sample is measured by the resistance method, which uses the relationship between the resistance value of the winding's self-current resistance after the temperature rises and the increase in resistance to determine the temperature rise of the group. The measured temperature rise is the average temperature rise. The winding temperature rise of the sample is measured after the power is cut off. The measured temperature rise should be corrected. The temperature of the winding at the moment of power cut can be obtained by extending the cooling curve and extrapolating to the moment of cutting off the line. When the extrapolation method is used: the time from cutting off the power to measuring the first point reading of the cooling curve should be as short as possible. The measuring points of the cooling curve are generally 5~6 points. The temperature rise of the burning group is calculated as follows: NR=R2(234.5+h)-(2 -t)
A—Temperature rise, unit is K:
R2—Winding resistance during test, unit is 2:R—Winding resistance before test, unit is self:t—Ambient temperature before test, unit is ℃;12
Ambient temperature during test, unit is ℃
The measurement of winding resistance before test should be carried out after the sample is placed in the air for 5 hours. 6.1.3.3 Measurement of laboratory ambient temperature
The laboratory ambient temperature should be measured at the beginning and during the test. The ambient temperature can be measured by several thermometers distributed around the tool. The thermometer is placed 1m-~2m away from the tool, and the ball position is the same as the test The axis of the sample is on the same plane and should be protected from external radiant heat and airflow from the tool outlet. Within Smin before measuring the temperature rise, take the average value of the thermometer readings, which is the ambient temperature of the laboratory during the life test.
6.1.3.4 Sample temperature
During the life test, the sample temperature is the sample temperature rise plus the laboratory ambient temperature. 6.1.4 Application of mechanical stress
During the test, the high-speed centrifugal force generated by the sample running at the specified load and no-load at the corresponding temperature of the predetermined temperature level and the impact force generated by frequent starting are the mechanical stress applied to the sample. This ensures that the size of the mechanical stress on the sample is consistent with the power tool. The mechanical stresses in actual operation are similar, so the combined effects of heat and mechanical stresses on the insulation structure in actual operation of the power tool can be simulated.
JB/T10321-2002
The sample shall not have additional mechanical stress caused by incorrect installation. Since the life of the insulation structure is assessed, the sample does not need to be subjected to axial force.
6.2 Test cycle
The test cycle is selected according to the actual working conditions. Each test cycle is 1205. Each cycle is as follows: Under rated voltage
No-load operation
Under specified load
Note 1: The sample test is called, and the temperature of the insulation structure is guaranteed to be (1 25+2) Test under the condition of power off and stop
Note 2: The test should be carried out continuously and can be carried out intermittently. In case of special circumstances, such as damage to non-assessed parts or failure of the excavation device, it is allowed to stop the machine and continue the test after the situation is normalized, but it is necessary to wait until the specified temperature is reached before continuing and the continuous test time is counted. 6.3 Test equipment
Any test equipment that can meet the requirements of 6.1 and 6.2 of this standard can be used as life test equipment. At present, the test equipment that meets the requirements of 6.1 and 6.2 of this standard includes two test equipment: the towing method (using an electric tool as a test piece to tow another generator as a load) and the water load method (testing the test piece with water as a load). In order to carry out the test according to the specified test cycle under the specified conditions, the test equipment must ensure that the specimen is running at the rated voltage of 1, and the control device of the test equipment must be able to meet the test cycle of load starting, load operation and recommended machine in 6.1 of this standard: 6.4 Test procedure
6.4.1 Before the test begins, the specimen should be visually inspected to confirm that the specimen has no copper or iron metal chips, and the paint film has no pores or cracks. After the dielectric strength test: measure the resistance between the commutator segments or the rotor after a comprehensive inspection: the specimen can be put into the test only if it is normal. 6.4.2 Before the test begins, measure the specimen winding resistance R and the laboratory environment temperature before the test begins in accordance with 6.1.3.2 and 6.1.3.3 of this standard.
6.4.3 The specimen should be rigidly mounted or mounted on a cushion to minimize the mechanical vibration of the specimen caused by incorrect installation. 6.4.4 After the test begins, adjust the sample load and the size of the air inlet, measure the winding resistance during the test, and when the test bar is adjusted to meet the requirements of 6.1.2 and 6.1.3.1 of this standard, start the test and record the test time. 6.4.5 During the test, the spark size and the temperature rise of the sample should be regularly observed to ensure that the sample operates normally under the specified test conditions. 6.4.6 During the test, clean the surface of the sample commutator with cotton fern industrial ethanol every 24 hours or so. 6.4.7 During the test, it is allowed to replace the sample brushes, oil the bearings, gears, etc., replace the towed generator, and regularly inspect and repair the test equipment. Continue the test after it is considered normal. 7 Determination of the end of life
7.1 Termination of test
During the life test, if the following conditions occur to the sample, it is considered that the sample cannot run and the test is terminated, and flames appear in the winding:
b) The winding is open-circuited:
c) The sample stalls and cannot run under the specified load: d) The winding is short-circuited or the commutator has ring fire: e) The sample stops running due to commutator damage or gear or shaft tooth wear. 7.2 Determination of abnormal damage
Since this test is to evaluate the life of the insulation structure, rather than the life or reliability of the entire power tool, it is necessary to analyze the terminated test sample. If the following conditions occur, although the sample cannot continue the test, it cannot be considered that the insulation structure is damaged: a) Due to failure of components or mechanical parts, such as commutator jump row, breakage, oil-containing bearing wear, wheel or shaft tooth wear. 4
JB/T10321--2002
b Short circuit caused by obvious manufacturing process defects, such as poor spot welding quality, overheating of welding points [caused by the disconnection of the circuit or the joint), short circuit between commutator segments and mechanical damage of brush holder. 7.3 End of life
The end of the life of the insulation structure is based on the stall and ring fire of the sample caused by short circuit or burnout of the winding.
8 Data evaluation
8.1 Calculation of the end of the life of the insulation structure: Calculate the actual operation time of the sample at the specified temperature according to 7.3 of this standard (excluding the time of intermediate maintenance, troubleshooting and stopping the test midway). 8.2 The life value of the insulation structure is based on the average value of 5 samples. 8.3 If the average value of the sample exceeds the specified value in 4.2 of this standard, the life value of the insulation structure can be judged to be qualified. If the test of the sample is not terminated due to the reason for the termination of the life of the insulation structure in 7.3 of this standard, and the life values ​​of at least 3 tested insulation structures all exceed the life value specified in 4.2 of this standard, the life of the insulation structure can be judged to be qualified. 8.4: Evaluation of the temperature level of the insulation structure: If the service life of the insulation structure to be evaluated exceeds the service life specified in 4.2 of this standard at 130℃, the temperature level of the insulation structure can be evaluated as Class B. 9 Inspection rules
9.1 The test item H listed in this standard is to determine the life of the insulation structure of the electric motor for electric tools, not to assess the temperature grade of the insulation structure to Class B.
9.2 The Class B insulation structure assessed by this standard shall be inspected by this standard in the following cases: a) The insulation material composition and insulation treatment process of the insulation structure are changed. b) A new insulation structure is used.
c) The main insulation material in the insulation structure is produced by a different unit and has not been tested by the standard. Assessor. 10 Test report
The test report should include:
a) Description of the product name, insulation structure and components of the tested sample (such as the name, brand, manufacturer and insulation process of the insulating varnish, enameled wire, slot insulation and other materials). b) Test equipment, test method and test unit used during the inspection: c) Sample inspection situation.
d) Analysis of test results, and situations where the sample cannot be tested further due to damage to non-assessed parts. e) Evaluation of the insulation structure life and temperature level of the sample.2 Temperature rise measurement
The temperature rise of the sample is measured by the resistance method, which uses the relationship between the resistance value of the winding's self-current resistance after the temperature rises and the resistance value that should increase to determine the temperature rise of the group. The measured temperature rise is the average temperature rise. The winding temperature rise of the sample is measured after the power is cut off. The measured temperature rise should be corrected. The temperature of the winding at the moment of power cut off can be obtained by extending the cooling curve and extrapolating it to the moment of cutting off the line. When the extrapolation method is used: the time from cutting off the power to measuring the first point reading of the cooling curve should be as short as possible. The measurement points of the cooling curve are generally 5~6 points. The temperature rise of the burning group is calculated as follows: NR = R2 (234.5 + h) - (2 - t)
A—temperature rise, unit is K:
R2—winding resistance during the test, unit is 2: R—winding resistance before the start of the test, unit is: t—ambient temperature before the start of the test, unit is ℃; 12
ambient temperature during the test, unit is ℃
The measurement of the group resistance before the test should be carried out after the sample is placed in the air for 5 hours. 6.1.3.3 Measurement of laboratory ambient temperature
The laboratory ambient temperature should be measured at the beginning and during the test. The ambient temperature can be measured by several thermometers distributed around the tool. The thermometer is placed 1m-~2m away from the tool, and the ball position is on the same plane as the axis of the sample, and it should be prevented from the influence of external radiation heat and air flow at the tool outlet. In the Smin before measuring the temperature rise, take the average value of the readings of each thermometer, which is the ambient temperature of the laboratory during the life test.
6.1.3.4 Sample temperature
The sample temperature during the life test is the sample temperature rise plus the laboratory ambient temperature. 6.1.4 Application of mechanical stress
During the test, the high-speed centrifugal force generated by the operation of the sample under the specified load and no-load at the corresponding temperature of the predetermined temperature level and the impact force generated by frequent starting are the mechanical stress applied to the sample. This ensures that the size of the mechanical stress on the sample is close to the mechanical stress on the power tool during actual operation, so it can simulate the comprehensive effect of heat and mechanical stress on the insulation structure of the power tool during actual operation.
JB/T10321-2002
The sample shall not have additional mechanical stress caused by incorrect installation. Since the life of the insulation structure is assessed, the sample does not need to be subjected to axial force.
6.2 Test cycle
The test cycle is selected according to the actual working conditions. Each test cycle is 1205. Each cycle is as follows: Under rated voltage
No-load operation
Under specified load
Note 1: The sample test is carried out at a temperature of (125+2)°C and the power is cut off and stopped
Note 2: The test should be carried out continuously and can be carried out at intervals. In case of special circumstances, such as damage to non-assessed parts or failure of the excavation device, the machine may be shut down and the test may be continued after the situation has returned to normal. However, the test may be continued and the continuous test time shall be counted only after the specified temperature is reached. 6.3 Test equipment www.bzxz.net
Any test equipment that meets the requirements of 6.1 and 6.2 of this standard can be used as life test equipment. Currently, the test equipment that meets the requirements of 6.1 and 6.2 of this standard includes the towing method (using an electric tool as the specimen to tow another generator as the load) and the water load method (the specimen is tested with water as the load). In order to carry out the test according to the specified test cycle under the specified conditions, the test equipment must ensure that the specimen is running at the rated voltage of 1, and the control device of the test equipment must be able to meet the test cycle of load starting, load operation and recommended machine in 6.1 of this standard: 6.4 Test procedure
6.4.1 Before the test begins, the specimen should be visually inspected to confirm that the specimen has no copper or iron metal chips, and the paint film has no pores or cracks. After the dielectric strength test: measure the resistance between the commutator segments or the rotor after a comprehensive inspection: the specimen can be put into the test only if it is normal. 6.4.2 Before the test begins, measure the specimen winding resistance R and the laboratory environment temperature before the test begins in accordance with 6.1.3.2 and 6.1.3.3 of this standard.
6.4.3 The specimen should be rigidly mounted or mounted on a cushion to minimize the mechanical vibration of the specimen caused by incorrect installation. 6.4.4 After the test begins, adjust the sample load and the size of the air inlet, measure the winding resistance during the test, and when the test bar is adjusted to meet the requirements of 6.1.2 and 6.1.3.1 of this standard, start the test and record the test time. 6.4.5 During the test, the spark size and the temperature rise of the sample should be regularly observed to ensure that the sample operates normally under the specified test conditions. 6.4.6 During the test, clean the surface of the sample commutator with cotton fern industrial ethanol every 24 hours or so. 6.4.7 During the test, it is allowed to replace the sample brushes, oil the bearings, gears, etc., replace the towed generator, and regularly inspect and repair the test equipment. Continue the test after it is considered normal. 7 Determination of the end of life
7.1 Termination of test
During the life test, if the following conditions occur to the sample, it is considered that the sample cannot run and the test is terminated, and flames appear in the winding:
b) The winding is open-circuited:
c) The sample stalls and cannot run under the specified load: d) The winding is short-circuited or the commutator has ring fire: e) The sample stops running due to commutator damage or gear or shaft tooth wear. 7.2 Determination of abnormal damage
Since this test is to evaluate the life of the insulation structure, rather than the life or reliability of the entire power tool, it is necessary to analyze the terminated test sample. If the following conditions occur, although the sample cannot continue the test, it cannot be considered that the insulation structure is damaged: a) Due to failure of components or mechanical parts, such as commutator jump row, breakage, oil-containing bearing wear, wheel or shaft tooth wear. 4
JB/T10321--2002
b Short circuit caused by obvious manufacturing process defects, such as poor spot welding quality, overheating of welding points [caused by the disconnection of the circuit or the joint), short circuit between commutator segments and mechanical damage of brush holder. 7.3 End of life
The end of the life of the insulation structure is based on the stall and ring fire of the sample caused by short circuit or burnout of the winding.
8 Data evaluation
8.1 Calculation of the end of the life of the insulation structure: Calculate the actual operation time of the sample at the specified temperature according to 7.3 of this standard (excluding the time of intermediate maintenance, troubleshooting and stopping the test midway). 8.2 The life value of the insulation structure is based on the average value of 5 samples. 8.3 If the average value of the sample exceeds the specified value in 4.2 of this standard, the life value of the insulation structure can be judged to be qualified. If the test of the sample is not terminated due to the reason for the termination of the life of the insulation structure in 7.3 of this standard, and the life values ​​of at least 3 tested insulation structures all exceed the life value specified in 4.2 of this standard, the life of the insulation structure can be judged to be qualified. 8.4: Evaluation of the temperature level of the insulation structure: If the service life of the insulation structure to be evaluated exceeds the service life specified in 4.2 of this standard at 130℃, the temperature level of the insulation structure can be evaluated as Class B. 9 Inspection rules
9.1 The test item H listed in this standard is to determine the life of the insulation structure of the electric motor for electric tools, not to assess the temperature grade of the insulation structure to Class B.
9.2 The Class B insulation structure assessed by this standard shall be inspected by this standard in the following cases: a) The insulation material composition and insulation treatment process of the insulation structure are changed. b) A new insulation structure is used.
c) The main insulation material in the insulation structure is produced by a different unit and has not been tested by the standard. Assessor. 10 Test report
The test report should include:
a) Description of the product name, insulation structure and components of the tested sample (such as the name, brand, manufacturer and insulation process of the insulating varnish, enameled wire, slot insulation and other materials). b) Test equipment, test method and test unit used during the inspection: c) Sample inspection situation.
d) Analysis of test results, and situations where the sample cannot be tested further due to damage to non-assessed parts. e) Evaluation of the insulation structure life and temperature level of the sample.2 Temperature rise measurement
The temperature rise of the sample is measured by the resistance method, which uses the relationship between the resistance value of the winding's self-current resistance after the temperature rises and the resistance value that should increase to determine the temperature rise of the group. The measured temperature rise is the average temperature rise. The winding temperature rise of the sample is measured after the power is cut off. The measured temperature rise should be corrected. The temperature of the winding at the moment of power cut off can be obtained by extending the cooling curve and extrapolating it to the moment of cutting off the line. When the extrapolation method is used: the time from cutting off the power to measuring the first point reading of the cooling curve should be as short as possible. The measurement points of the cooling curve are generally 5~6 points. The temperature rise of the burning group is calculated as follows: NR = R2 (234.5 + h) - (2 - t)
A—temperature rise, unit is K:
R2—winding resistance during the test, unit is 2: R—winding resistance before the start of the test, unit is: t—ambient temperature before the start of the test, unit is ℃; 12
ambient temperature during the test, unit is ℃
The measurement of the group resistance before the test should be carried out after the sample is placed in the air for 5 hours. 6.1.3.3 Measurement of laboratory ambient temperature
The laboratory ambient temperature should be measured at the beginning and during the test. The ambient temperature can be measured by several thermometers distributed around the tool. The thermometer is placed 1m-~2m away from the tool, and the ball position is on the same plane as the axis of the sample, and it should be prevented from the influence of external radiation heat and air flow at the tool outlet. In the Smin before measuring the temperature rise, take the average value of the readings of each thermometer, which is the ambient temperature of the laboratory during the life test.
6.1.3.4 Sample temperature
The sample temperature during the life test is the sample temperature rise plus the laboratory ambient temperature. 6.1.4 Application of mechanical stress
During the test, the high-speed centrifugal force generated by the operation of the sample under the specified load and no-load at the corresponding temperature of the predetermined temperature level and the impact force generated by frequent starting are the mechanical stress applied to the sample. This ensures that the size of the mechanical stress on the sample is close to the mechanical stress on the power tool during actual operation, so it can simulate the comprehensive effect of heat and mechanical stress on the insulation structure of the power tool during actual operation.
JB/T10321-2002
The sample shall not have additional mechanical stress caused by incorrect installation. Since the life of the insulation structure is assessed, the sample does not need to be subjected to axial force.
6.2 Test cycle
The test cycle is selected according to the actual working conditions. Each test cycle is 1205. Each cycle is as follows: Under rated voltage
No-load operation
Under specified load
Note 1: The sample test is carried out at a temperature of (125+2)°C and the power is cut off and stopped
Note 2: The test should be carried out continuously and can be carried out at intervals. In case of special circumstances, such as damage to non-assessed parts or failure of the excavation device, the machine may be shut down and the test may be continued after the situation has returned to normal. However, the test may be continued and the continuous test time shall be counted only after the specified temperature is reached. 6.3 Test equipment
Any test equipment that meets the requirements of 6.1 and 6.2 of this standard can be used as life test equipment. Currently, the test equipment that meets the requirements of 6.1 and 6.2 of this standard includes the towing method (using an electric tool as the specimen to tow another generator as the load) and the water load method (the specimen is tested with water as the load). In order to carry out the test according to the specified test cycle under the specified conditions, the test equipment must ensure that the specimen is running at the rated voltage of 1, and the control device of the test equipment must be able to meet the test cycle of load starting, load operation and recommended machine in 6.1 of this standard: 6.4 Test procedure
6.4.1 Before the test begins, the specimen should be visually inspected to confirm that the specimen has no copper or iron metal chips, and the paint film has no pores or cracks. After the dielectric strength test: measure the resistance between the commutator segments or the rotor after a comprehensive inspection: the specimen can be put into the test only if it is normal. 6.4.2 Before the test begins, measure the specimen winding resistance R and the laboratory environment temperature before the test begins in accordance with 6.1.3.2 and 6.1.3.3 of this standard.
6.4.3 The specimen should be rigidly mounted or mounted on a cushion to minimize the mechanical vibration of the specimen caused by incorrect installation. 6.4.4 After the test begins, adjust the sample load and the size of the air inlet, measure the winding resistance during the test, and when the test bar is adjusted to meet the requirements of 6.1.2 and 6.1.3.1 of this standard, start the test and record the test time. 6.4.5 During the test, the spark size and the temperature rise of the sample should be regularly observed to ensure that the sample operates normally under the specified test conditions. 6.4.6 During the test, clean the surface of the sample commutator with cotton fern industrial ethanol every 24 hours or so. 6.4.7 During the test, it is allowed to replace the sample brushes, oil the bearings, gears, etc., replace the towed generator, and regularly inspect and repair the test equipment. Continue the test after it is considered normal. 7 Determination of the end of life
7.1 Termination of test
During the life test, if the following conditions occur to the sample, it is considered that the sample cannot run and the test is terminated, and flames appear in the winding:
b) The winding is open-circuited:
c) The sample stalls and cannot run under the specified load: d) The winding is short-circuited or the commutator has ring fire: e) The sample stops running due to commutator damage or gear or shaft tooth wear. 7.2 Determination of abnormal damage
Since this test is to evaluate the life of the insulation structure, rather than the life or reliability of the entire power tool, it is necessary to analyze the terminated test sample. If the following conditions occur, although the sample cannot continue the test, it cannot be considered that the insulation structure is damaged: a) Due to failure of components or mechanical parts, such as commutator jump row, breakage, oil-containing bearing wear, wheel or shaft tooth wear. 4
JB/T10321--2002
b Short circuit caused by obvious manufacturing process defects, such as poor spot welding quality, overheating of welding points [caused by the disconnection of the circuit or the joint), short circuit between commutator segments and mechanical damage of brush holder. 7.3 End of life
The end of the life of the insulation structure is based on the stall and ring fire of the sample caused by short circuit or burnout of the winding.
8 Data evaluation
8.1 Calculation of the end of the life of the insulation structure: Calculate the actual operation time of the sample at the specified temperature according to 7.3 of this standard (excluding the time of intermediate maintenance, troubleshooting and stopping the test midway). 8.2 The life value of the insulation structure is based on the average value of 5 samples. 8.3 If the average value of the sample exceeds the specified value in 4.2 of this standard, the life value of the insulation structure can be judged to be qualified. If the test of the sample is not terminated due to the reason for the termination of the life of the insulation structure in 7.3 of this standard, and the life values ​​of at least 3 tested insulation structures all exceed the life value specified in 4.2 of this standard, the life of the insulation structure can be judged to be qualified. 8.4: Evaluation of the temperature level of the insulation structure: If the service life of the insulation structure to be evaluated exceeds the service life specified in 4.2 of this standard at 130℃, the temperature level of the insulation structure can be evaluated as Class B. 9 Inspection rules
9.1 The test item H listed in this standard is to determine the life of the insulation structure of the electric motor for electric tools, not to assess the temperature grade of the insulation structure to Class B.
9.2 The Class B insulation structure assessed by this standard shall be inspected by this standard in the following cases: a) The insulation material composition and insulation treatment process of the insulation structure are changed. b) A new insulation structure is used.
c) The main insulation material in the insulation structure is produced by a different unit and has not been tested by the standard. Assessor. 10 Test report
The test report should include:
a) Description of the product name, insulation structure and components of the tested sample (such as the name, brand, manufacturer and insulation process of the insulating varnish, enameled wire, slot insulation and other materials). b) Test equipment, test method and test unit used during the inspection: c) Sample inspection situation.
d) Analysis of test results, and situations where the sample cannot be tested further due to damage to non-assessed parts. e) Evaluation of the life and temperature level of the sample insulation structure.3 Measurement of laboratory ambient temperature
The laboratory ambient temperature should be measured at the beginning and during the test. The ambient temperature can be measured by several thermometers distributed around the tool. The thermometer is placed 1m-~2m away from the tool, with the ball position and the axis of the sample on the same plane, and should be protected from external radiant heat and the influence of the air flow at the tool outlet. In the Smin before measuring the temperature rise, take the average value of the readings of each thermometer, which is the ambient temperature of the laboratory during the life test.
6.1.3.4 Sample temperature
The sample temperature during the life test is the sample temperature rise plus the laboratory ambient temperature. 6.1.4 Application of mechanical stress
During the test, the high-speed centrifugal force generated by the operation of the sample under the specified load and no-load at the corresponding temperature of the predetermined temperature level and the impact force generated by frequent starting are the mechanical stress applied to the sample. This ensures that the size of the mechanical stress on the sample is close to the mechanical stress on the power tool during actual operation, so it can simulate the comprehensive effect of heat and mechanical stress on the insulation structure of the power tool during actual operation.
JB/T10321-2002
The sample shall not have additional mechanical stress caused by incorrect installation. Since the life of the insulation structure is assessed, the sample does not need to be subjected to axial force.
6.2 Test cycle
The test cycle is selected according to the actual working conditions. Each test cycle is 1205. Each cycle is as follows: Under rated voltage
No-load operation
Under specified load
Note 1: The sample test is carried out at a temperature of (125+2)°C and the power is cut off and stopped
Note 2: The test should be carried out continuously and can be carried out at intervals. In case of special circumstances, such as damage to non-assessed parts or failure of the excavation device, the machine may be shut down and the test may be continued after the situation has returned to normal. However, the test may be continued and the continuous test time shall be counted only after the specified temperature is reached. 6.3 Test equipment
Any test equipment that meets the requirements of 6.1 and 6.2 of this standard can be used as life test equipment. Currently, the test equipment that meets the requirements of 6.1 and 6.2 of this standard includes the towing method (using an electric tool as the specimen to tow another generator as the load) and the water load method (the specimen is tested with water as the load). In order to carry out the test according to the specified test cycle under the specified conditions, the test equipment must ensure that the specimen is running at the rated voltage of 1, and the control device of the test equipment must be able to meet the test cycle of load starting, load operation and recommended machine in 6.1 of this standard: 6.4 Test procedure
6.4.1 Before the test begins, the specimen should be visually inspected to confirm that the specimen has no copper or iron metal chips, and the paint film has no pores or cracks. After the dielectric strength test: measure the resistance between the commutator segments or the rotor after a comprehensive inspection: the specimen can be put into the test only if it is normal. 6.4.2 Before the test begins, measure the specimen winding resistance R and the laboratory environment temperature before the test begins in accordance with 6.1.3.2 and 6.1.3.3 of this standard.
6.4.3 The specimen should be rigidly mounted or mounted on a cushion to minimize the mechanical vibration of the specimen caused by incorrect installation. 6.4.4 After the test begins, adjust the sample load and the size of the air inlet, measure the winding resistance during the test, and when the test bar is adjusted to meet the requirements of 6.1.2 and 6.1.3.1 of this standard, start the test and record the test time. 6.4.5 During the test, the spark size and the temperature rise of the sample should be regularly observed to ensure that the sample operates normally under the specified test conditions. 6.4.6 During the test, clean the surface of the sample commutator with cotton fern industrial ethanol every 24 hours or so. 6.4.7 During the test, it is allowed to replace the sample brushes, oil the bearings, gears, etc., replace the towed generator, and regularly inspect and repair the test equipment. Continue the test after it is considered normal. 7 Determination of the end of life
7.1 Termination of test
During the life test, if the following conditions occur to the sample, it is considered that the sample cannot run and the test is terminated, and flames appear in the winding:
b) The winding is open-circuited:
c) The sample stalls and cannot run under the specified load: d) The winding is short-circuited or the commutator has ring fire: e) The sample stops running due to commutator damage or gear or shaft tooth wear. 7.2 Determination of abnormal damage
Since this test is to evaluate the life of the insulation structure, rather than the life or reliability of the entire power tool, it is necessary to analyze the terminated test sample. If the following conditions occur, although the sample cannot continue the test, it cannot be considered that the insulation structure is damaged: a) Due to failure of components or mechanical parts, such as commutator jump row, breakage, oil-containing bearing wear, wheel or shaft tooth wear. 4
JB/T10321--2002
b Short circuit caused by obvious manufacturing process defects, such as poor spot welding quality, overheating of welding points [caused by the disconnection of the circuit or the joint), short circuit between commutator segments and mechanical damage of brush holder. 7.3 End of life
The end of the life of the insulation structure is based on the stall and ring fire of the sample caused by short circuit or burnout of the winding.
8 Data evaluation
8.1 Calculation of the end of the life of the insulation structure: Calculate the actual operation time of the sample at the specified temperature according to 7.3 of this standard (excluding the time of intermediate maintenance, troubleshooting and stopping the test midway). 8.2 The life value of the insulation structure is based on the average value of 5 samples. 8.3 If the average value of the sample exceeds the specified value in 4.2 of this standard, the life value of the insulation structure can be judged to be qualified. If the test of the sample is not terminated due to the reason for the termination of the life of the insulation structure in 7.3 of this standard, and the life values ​​of at least 3 tested insulation structures all exceed the life value specified in 4.2 of this standard, the life of the insulation structure can be judged to be qualified. 8.4: Evaluation of the temperature level of the insulation structure: If the service life of the insulation structure to be evaluated exceeds the service life specified in 4.2 of this standard at 130℃, the temperature level of the insulation structure can be evaluated as Class B. 9 Inspection rules
9.1 The test item H listed in this standard is to determine the life of the insulation structure of the electric motor for electric tools, not to assess the temperature grade of the insulation structure to Class B.
9.2 The Class B insulation structure assessed by this standard shall be inspected by this standard in the following cases: a) The insulation material composition and insulation treatment process of the insulation structure are changed. b) A new insulation structure is used.
c) The main insulation material in the insulation structure is produced by a different unit and has not been tested by the standard. Assessor. 10 Test report
The test report should include:
a) Description of the product name, insulation structure and components of the tested sample (such as the name, brand, manufacturer and insulation process of the insulating varnish, enameled wire, slot insulation and other materials). b) Test equipment, test method and test unit used during the inspection: c) Sample inspection situation.
d) Analysis of test results, and situations where the sample cannot be tested further due to damage to non-assessed parts. e) Evaluation of the life and temperature level of the sample insulation structure.3 Measurement of laboratory ambient temperature
The laboratory ambient temperature should be measured at the beginning and during the test. The ambient temperature can be measured by several thermometers distributed around the tool. The thermometer is placed 1m-~2m away from the tool, with the ball position and the axis of the sample on the same plane, and should be protected from external radiant heat and the influence of the air flow at the tool outlet. In the Smin before measuring the temperature rise, take the average value of the readings of each thermometer, which is the ambient temperature of the laboratory during the life test.
6.1.3.4 Sample temperature
The sample temperature during the life test is the sample temperature rise plus the laboratory ambient temperature. 6.1.4 Application of mechanical stress
During the test, the high-speed centrifugal force generated by the operation of the sample under the specified load and no-load at the corresponding temperature of the predetermined temperature level and the impact force generated by frequent starting are the mechanical stress applied to the sample. This ensures that the size of the mechanical stress on the sample is close to the mechanical stress on the power tool during actual operation, so it can simulate the comprehensive effect of heat and mechanical stress on the insulation structure of the power tool during actual operation.
JB/T10321-2002
The sample shall not have additional mechanical stress caused by incorrect installation. Since the life of the insulation structure is assessed, the sample does not need to be subjected to axial force.
6.2 Test cycle
The test cycle is selected according to the actual working conditions. Each test cycle is 1205. Each cycle is as follows: Under rated voltage
No-load operation
Under specified load
Note 1: The sample test is carried out at a temperature of (125+2)°C and the power is cut off and stopped
Note 2: The test should be carried out continuously and can be carried out at intervals. In case of special circumstances, such as damage to non-assessed parts or failure of the excavation device, the machine may be shut down and the test may be continued after the situation has returned to normal. However, the test may be continued and the continuous test time shall be counted only after the specified temperature is reached. 6.3 Test equipment
Any test equipment that meets the requirements of 6.1 and 6.2 of this standard can be used as life test equipment. Currently, the test equipment that meets the requirements of 6.1 and 6.2 of this standard includes the towing method (using an electric tool as the specimen to tow another generator as the load) and the water load method (the specimen is tested with water as the load). In order to carry out the test according to the specified test cycle under the specified conditions, the test equipment must ensure that the specimen is running at the rated voltage of 1, and the control device of the test equipment must be able to meet the test cycle of load starting, load operation and recommended machine in 6.1 of this standard: 6.4 Test procedure
6.4.1 Before the test begins, the specimen should be visually inspected to confirm that the specimen has no copper or iron metal chips, and the paint film has no pores or cracks. After the dielectric strength test: measure the resistance between the commutator segments or the rotor after a comprehensive inspection: the specimen can be put into the test only if it is normal. 6.4.2 Before the test begins, measure the specimen winding resistance R and the laboratory environment temperature before the test begins in accordance with 6.1.3.2 and 6.1.3.3 of this standard.
6.4.3 The specimen should be rigidly mounted or mounted on a cushion to minimize the mechanical vibration of the specimen caused by incorrect installation. 6.4.4 After the test begins, adjust the sample load and the size of the air inlet, measure the winding resistance during the test, and when the test bar is adjusted to meet the requirements of 6.1.2 and 6.1.3.1 of this standard, start the test and record the test time. 6.4.5 During the test, the spark size and the temperature rise of the sample should be regularly observed to ensure that the sample operates normally under the specified test conditions. 6.4.6 During the test, clean the surface of the sample commutator with cotton fern industrial ethanol every 24 hours or so. 6.4.7 During the test, it is allowed to replace the sample brushes, oil the bearings, gears, etc., replace the towed generator, and regularly inspect and repair the test equipment. Continue the test after it is considered normal. 7 Determination of the end of life
7.1 Termination of test
During the life test, if the following conditions occur to the sample, it is considered that the sample cannot run and the test is terminated, and flames appear in the winding:
b) The winding is open-circuited:
c) The sample stalls and cannot run under the specified load: d) The winding is short-circuited or the commutator has ring fire: e) The sample stops running due to commutator damage or gear or shaft tooth wear. 7.2 Determination of abnormal damage
Since this test is to evaluate the life of the insulation structure, rather than the life or reliability of the entire power tool, it is necessary to analyze the terminated test sample. If the following conditions occur, although the sample cannot continue the test, it cannot be considered that the insulation structure is damaged: a) Due to failure of components or mechanical parts, such as commutator jump row, breakage, oil-containing bearing wear, wheel or shaft tooth wear. 4
JB/T10321--2002
b Short circuit caused by obvious manufacturing process defects, such as poor spot welding quality, overheating of welding points [caused by the disconnection of the circuit or the joint), short circuit between commutator segments and mechanical damage of brush holder. 7.3 End of life
The end of the life of the insulation structure is based on the stall and ring fire of the sample caused by short circuit or burnout of the winding.
8 Data evaluation
8.1 Calculation of the end of the life of the insulation structure: Calculate the actual operation time of the sample at the specified temperature according to 7.3 of this standard (excluding the time of intermediate maintenance, troubleshooting and stopping the test midway). 8.2 The life value of the insulation structure is based on the average value of 5 samples. 8.3 If the average value of the sample exceeds the specified value in 4.2 of this standard, the life value of the insulation structure can be judged to be qualified. If the test of the sample is not terminated due to the reason for the termination of the life of the insulation structure in 7.3 of this standard, and the life values ​​of at least 3 tested insulation structures all exceed the life value specified in 4.2 of this standard, the life of the insulation structure can be judged to be qualified. 8.4: Evaluation of the temperature level of the insulation structure: If the service life of the insulation structure to be evaluated exceeds the service life specified in 4.2 of this standard at 130℃, the temperature level of the insulation structure can be evaluated as Class B. 9 Inspection rules
9.1 The test item H listed in this standard is to determine the life of the insulation structure of the electric motor for electric tools, not to assess the temperature grade of the insulation structure to Class B.
9.2 The Class B insulation structure assessed by this standard shall be inspected by this standard in the following cases: a) The insulation material composition and insulation treatment process of the insulation structure are changed. b) A new insulation structure is used.
c) The main insulation material in the insulation structure is produced by a different unit and has not been tested by the standard. Assessor. 10 Test report
The test report should include:
a) Description of the product name, insulation structure and components of the tested sample (such as the name, brand, manufacturer and insulation process of the insulating varnish, enameled wire, slot insulation and other materials). b) Test equipment, test method and test unit used during the inspection: c) Sample inspection situation.
d) Analysis of test results, and situations where the sample cannot be tested further due to damage to non-assessed parts. e) Evaluation of the life and temperature level of the sample insulation structure.2. Any test equipment that meets the requirements of this standard can be used as life test equipment. Currently, the test equipment that meets the requirements of 6.1 and 6.2 of this standard includes the towing method (using one electric tool as the specimen to tow another generator as the load) and the water load method (the specimen is tested with water as the load). In order to carry out the test according to the specified test cycle under the specified conditions, the test equipment must ensure that the specimen is running at the rated voltage of 1, and the control device of the test equipment must be able to meet the test cycle of load starting, load operation and recommended machine in 6.1 of this standard: 6.4 Test procedure
6.4.1 Before the test begins, the specimen should be visually inspected to confirm that the specimen has no copper or iron metal chips, and the paint film has no pores or cracks. After the dielectric strength test: measure the resistance between the commutator segments or the rotor after a comprehensive inspection: the specimen can be put into the test only if it is normal. 6.4.2 Before the test begins, measure the specimen winding resistance R and the laboratory environment temperature before the test begins in accordance with 6.1.3.2 and 6.1.3.3 of this standard.
6.4.3 The specimen should be rigidly mounted or mounted on a cushion to minimize the mechanical vibration of the specimen caused by incorrect installation. 6.4.4 After the test begins, adjust the sample load and the size of the air inlet, measure the winding resistance during the test, and when the test bar is adjusted to meet the requirements of 6.1.2 and 6.1.3.1 of this standard, start the test and record the test time. 6.4.5 During the test, the spark size and the temperature rise of the sample should be regularly observed to ensure that the sample operates normally under the specified test conditions. 6.4.6 During the test, clean the surface of the sample commutator with cotton fern industrial ethanol every 24 hours or so. 6.4.7 During the test, it is allowed to replace the sample brushes, oil the bearings, gears, etc., replace the towed generator, and regularly inspect and repair the test equipment. Continue the test after it is considered normal. 7 Determination of the end of life
7.1 Termination of test
During the life test, if the following conditions occur to the sample, it is considered that the sample cannot run and the test is terminated, and flames appear in the winding:
b) The winding is open-circuited:
c) The sample stalls and cannot run under the specified load: d) The winding is short-circuited or the commutator has ring fire: e) The sample stops running due to commutator damage or gear or shaft tooth wear. 7.2 Determination of abnormal damage
Since this test is to evaluate the life of the insulation structure, rather than the life or reliability of the entire power tool, it is necessary to analyze the terminated test sample. If the following conditions occur, although the sample cannot continue the test, it cannot be considered that the insulation structure is damaged: a) Due to failure of components or mechanical parts, such as commutator jump row, breakage, oil-containing bearing wear, wheel or shaft tooth wear. 4
JB/T10321--2002
b Short circuit caused by obvious manufacturing process defects, such as poor spot welding quality, overheating of welding points [caused by the disconnection of the circuit or the joint), short circuit between commutator segments and mechanical damage of brush holder. 7.3 End of life
The end of the life of the insulation structure is based on the stall and ring fire of the sample caused by short circuit or burnout of the winding.
8 Data evaluation
8.1 Calculation of the end of the life of the insulation structure: Calculate the actual operation time of the sample at the specified temperature according to 7.3 of this standard (excluding the time of intermediate maintenance, troubleshooting and stopping the test midway). 8.2 The life value of the insulation structure is based on the average value of 5 samples. 8.3 If the average value of the sample exceeds the specified value in 4.2 of this standard, the life value of the insulation structure can be judged to be qualified. If the test of the sample is not terminated due to the reason for the termination of the life of the insulation structure in 7.3 of this standard, and the life values ​​of at least 3 tested insulation structures all exceed the life value specified in 4.2 of this standard, the life of the insulation structure can be judged to be qualified. 8.4: Evaluation of the temperature level of the insulation structure: If the service life of the insulation structure to be evaluated exceeds the service life specified in 4.2 of this standard at 130℃, the temperature level of the insulation structure can be evaluated as Class B. 9 Inspection rules
9.1 The test item H listed in this standard is to determine the life of the insulation structure of the electric motor for electric tools, not to assess the temperature grade of the insulation structure to Class B.
9.2 The Class B insulation structure assessed by this standard shall be inspected by this standard in the following cases: a) The insulation material composition and insulation treatment process of the insulation structure are changed. b) A new insulation structure is used.
c) The main insulation material in the insulation structure is produced by a different unit and has not been tested by the standard. Assessor. 10 Test report
The test report should include:
a) Description of the product name, insulation structure and components of the tested sample (such as the name, brand, manufacturer and insulation process of the insulating varnish, enameled wire, slot insulation and other materials). b) Test equipment, test method and test unit used during the inspection: c) Sample inspection situation.
d) Analysis of test results, and situations where the sample cannot be tested further due to damage to non-assessed parts. e) Evaluation of the life and temperature level of the sample insulation structure.2. Any test equipment that meets the requirements of this standard can be used as life test equipment. Currently, the test equipment that meets the requirements of 6.1 and 6.2 of this standard includes the towing method (using one electric tool as the specimen to tow another generator as the load) and the water load method (the specimen is tested with water as the load). In order to carry out the test according to t
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