This standard is applicable to the rapid thermal aging test of electrical insulation impregnation paint and varnished cloth with soft paint film, expressed in terms of temperature index (td) and thermal life line equation. This standard cannot replace the conventional thermal aging test method. JB/T 1544-1999 Rapid thermal aging test method for electrical insulation impregnation paint and varnished cloth - hot focus oblique method JB/T1544-1999 Standard download decompression password: www.bzxz.net

The standard of the People's Republic of China for pressure machinery industry JB/T15441999
1999-08-064
2000-01-01
JB/T1544±1999
This standard is a revision of JB1544-76 "Test method for rapid evaluation of thermal aging performance of electrical insulating paint and varnished cloth - thermal focus method".
The main differences between this standard and JB1544-76 are: 1. The content of the standard name and scope has been modified; 2. J. The thermal life limit value of 30000h is changed to 20000h; 3 In order to improve the accuracy of the test results, the thermal life value of the constant temperature point function test is changed from not less than 300h to not less than 500h; 4 The thermocouple is changed from complying with the provisions of JB913 to complying with the technical conditions of industrial thermocouples of JB/T9238-1999: 5 The sample preparation, test equipment, test conditions, test procedures, and result calculations that are in accordance with (or should comply with) JB/T1763-76 "Test Method for Evaluating Thermal Aging Performance of Insulating Dipping Varnish - Curved Surface Electrode Method" and JB/T1764-76 "Test Method for Evaluating Thermal Aging Performance of Insulating Varnish Cloth - Curved Surface Electrode Method" are changed to comply with (or should comply with) the relevant provisions of IEC60370, IEC60216-4-1 and GB/T1408-1989.
6 Delete Appendix 1 and change Appendix 2 to Table 3. This standard will replace JB1544-76 from the date of implementation. This standard is proposed and managed by the National Technical Committee for Standardization of Insulating Materials. The drafting unit of this standard is Xi'an Insulating Materials Factory. The drafter of this standard is Bai Yi.
This standard was first issued in 1977 and revised for the first time in 1999. This standard is entrusted to the National Technical Committee for Standardization of Insulating Materials for interpretation. 1
1 Scope
JB/T15441999
JB154476
This standard is applicable to the rapid thermal aging test of electrical insulating impregnating varnishes and varnished cloth with soft paint film, expressed by temperature index (t) and thermal life line equation.
This standard cannot replace the conventional thermal aging test method. 2 Referenced 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 version of the following standards. GB/T1408—1989
JB/T9238—1999
IEC60216—4—1:1990
IEC60370:1971
3Test basis
Test method for power frequency electrical strength of solid insulating materials (neqtEC60243:1967)Technical conditions for industrial thermocouples
Guidelines for determining the heat resistance of electrical insulating materials Part 4: Aging ovensOvens
Heat resistance of insulating varnishes Test Procedure 1
Electrical Strength Method
Section 1: Single Chamber
This standard is based on the theory of electrical insulation thermal life test, Lgt=a+b/T, that is, the logarithm of insulation life (t) is linearly related to the reciprocal of absolute temperature (T), combining the functional test at constant temperature with the thermal weight loss test at uniform temperature increase, that is, a functional test at a constant temperature point is performed by the conventional thermal aging test method to obtain the thermal life value at that temperature; the slope of the thermal life line is obtained from the thermogravimetric curve to quickly evaluate the thermal aging performance of the material.
4 Sample Preparation
4.1 The samples used for the functional test at a constant temperature point shall be prepared in accordance with the provisions of Chapter 2 of IEC60370. 4.2 The thermal weight loss sample shall be a powder or varnished cloth sample. 4.2.1 Powder sample
4.2.1.1 Take the same batch of impregnation paint or varnished cloth paint as the sample prepared in 4.1, and make a paint cake with a thickness of less than 3mm according to its curing conditions. Bake it at a temperature 30℃ higher than the expected temperature index for 8~24h:1999-08-06
2000-01-01
JB/T15441999
4.2.1.2 After baking, grind it into powder with a fineness of 100 mesh. 4.2.2 Varnished cloth sample
4.2.2.1 Take the varnished cloth used in 4.1 and cut it into small pieces of 1mm×1mm. 4.2.2.2 Baking conditions are the same as those for powder samples.
The prepared sample is stored in a desiccator. 5 Test equipment
5.1 Aging oven
According to the provisions of [EC60216-4-1.
5.2 Breakdown voltage device
According to the provisions of Chapter 5 of GB/T1408-1989. 5.3 Thermal analysis balance
5.3.1 The sensitivity of the thermal analysis balance is 0.1mg. 5.3.2
The heating mode of the electric furnace is uniform heating, and the heating speed deviation is less than 5%. Within the test temperature range, the zero drift of the thermal analysis balance is less than 0.1mg. The accuracy of automatic weight recording is ±0.1mg. 5.3.5 The accuracy of the automatic temperature recorder is not less than Class 1.0. 5.3.6 Thermocouples comply with the provisions of JB/T9238. 5.3.7
The temperature recording system should be calibrated.
6 Test conditions
The functional test at constant temperature shall be carried out according to the procedure of Chapter 5 of IEC60370. The test temperature shall be selected according to Table 1, and its thermal life value (t) shall be less than 500h.
Test temperature
Estimated range of temperature index
120~129
130-154
155-179
180-199
200-219
220~239
240 and above
6.2 Thermal weight loss test
6.2.1 Weigh the sample with a balance with a sensitivity of 0.1mg. 6.2.2 Test conditions
Total weight loss of sample: 8~20mg;
Heating rate: 3℃/min or 5℃/min;2
170~190
190~215
215~240
240~260
260-280
280~300
300~320
Test atmosphere: atmospheric pressure air.
7 Procedure
JB/T15441999
The functional test at constant temperature shall be carried out in accordance with the procedure of Chapter 5 of [EC60370]. 7.1
7.2Thermogravimetric test shall be carried out in accordance with the operating procedures of thermal analysis balance and the thermogravimetric curve shall be recorded. 8 Calculation
8.1 The thermal life value at the constant temperature point (t℃) shall be calculated according to Chapter 6 of IEC60370. 8.2 From the thermogravimetric curve, take the ten temperature values ​​corresponding to the weight loss of 5%~50% (interval of 5%), and calculate the apparent thermal decomposition activation energy E of the material according to the following empirical formula:
Wa-bzxZ.net
Total weight loss of the sample, mg:
△W-weight loss of the sample, mg:
(W/Wa)n-weight loss percentage;
E,=E. +RC.
t——Temperature value corresponding to each △W/Wa, ℃: R——Gas constant, 1.987
C. Coefficient;
E. Constant.
E. and RC shall be taken according to the test conditions as shown in Table 2. Table 2
Test conditions
8-20mg
3℃/min
5℃/min
The slope of the thermal life line:
Powder
Varnished cloth
). The value can be found from Table 3.
The average value of the two tests is taken as the result. The relative error of the two tests is not more than 2%. According to t, t, b, a=lgt
8.3 Calculate the temperature index t of the material according to the following formula: a is obtained.
Ig to -lgt
273+td
Where: o
- Thermal life limit value, take 20000ha
9 Test report
The test report should at least include the following contents: b
237 +t
JB/T15441999
a) Material name, model, manufacturer and production date; b) Temperature of constant temperature point functional test, time of each cycle and average value of electrical strength; c) Sample shape, total weight loss, heating rate, weight loss percentage and corresponding temperature value of thermogravimetric test; Table 3
JB/T15441999
d) Point and slope value of thermal life line (t, T, h); e) Thermal life equation, lgt=a+
f) Thermal focus slope method temperature index of material, ta; g) Start and end date of test.
). Instructions for use of table:
-). Find the weight loss percentage in the column, find the hundreds and tens digits of the corresponding temperature in the t. column; add the number corresponding to the temperature in the lower part of the table (
,
=697+13=710.
, ×
=15% corresponds to t=275℃, then
=35% t=358℃, then t, ×
)n=592+14=606.
JB/T15441999
880A1230
19XXAXX
100044
XXX,XXX
666 /
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