This standard specifies the technical requirements, test methods, inspection rules and marking, packaging, transportation and storage of power transformers and filter chokes for electronic equipment. This standard applies to dry-type power transformers and filter chokes for electronic equipment, with an operating voltage not higher than 5000V, a power frequency not higher than 1050Hz, and a weight not greater than 70kg. GB/T 15290-1994 General Technical Requirements for Power Transformers and Filter Chokes for Electronic Equipment GB/T15290-1994 Standard Download Decompression Password: www.bzxz.net

National Standard of the People's Republic of China
Power supply transformers and filter chokes for use in electronic equipment
Generic specification of power supply-transformers and filter chokes for use in electronic equipment
1 Subject content and scope of application
GB/T 15290--94
This standard specifies the technical requirements, test methods, inspection rules and marking, packaging, transportation of power supply transformers and filter chokes (hereinafter referred to as "components") for electronic equipment. This standard applies to dry-type power supply transformers and filter chokes for electronic equipment, with an operating voltage not higher than 5000 V, a power frequency not higher than 1 050 Hz, and a weight not greater than 70 kg. 2 Reference standards
GB2423.1 Basic environmental test procedures for electric and electronic products Test A: Low temperature test method GB2423.2 Basic environmental test procedures for electric and electronic products Test B: High temperature test method GB 2423.3 Basic environmental test procedures for electric and electronic products Test (a: Steady state damp heat test method
GB 2423. 4
Basic environmental test procedures for electric and electronic products Test Db: Alternating damp heat test method
Basic environmental test procedures for electric and electronic products Test Eb: Collision test method GB 2423. 10
Basic environmental test procedures for electric and electronic products Test Fc: Vibration (sinusoidal) test method Basic environmental test procedures for electric and electronic products Test: Mildew growth test method
GB2423.16E
GB 2423. 21
GB 2423. 22
GB2423.28
GB 2423, 29
Basic environmental test procedures for electric and electronic products Test M: Low pressure test method Basic environmental test procedures for electric and electronic products Test N: Temperature change test method Basic environmental test procedures for electric and electronic products Test T: Welding test method Basic environmental test procedures for electric and electronic products Test U, Strength of lead terminals and integral mounting parts GB2828 Batch inspection counting sampling procedures and sampling tables (applicable to inspection of continuous batches) GB2829
Periodic inspection counting sampling procedures and sampling tables (applicable to inspection of production process stability) GB8554 Test methods and test procedures for transformers and inductors for electronic and communication equipment SJ2488 Test methods for transformers, chokes and core noise for electrical equipment 3 Models
3.1 The model of a component consists of a name code, a working overflow grade mark, nominal parameters and a serial number, and the arrangement order is shown in Figure 1. Approved by the State Administration of Technical Supervision on December 6, 1994 and implemented on July 1, 1995
GB/T 15290—94
Serial number (Article 3.5)
Nominal number of silkworms (Article 3.4)
Working degree grade mark (Article 3.3)
Name code (Article 3.2)
3.2 Name code "Name code prefix \T" or "L\ respectively indicates transformer or inductor, and the last letter \D" or \E\ respectively indicates power supply or choke.
3.3 Working temperature grade mark is indicated by the working temperature grade mark of the component. Its working temperature grade mark and allowable working temperature are shown in the table 1.
Working temperature grade mark
Allowable working temperature, it
180 and above
3.4 ​​Nominal parameters The power transformer is expressed by the nominal power (V·A) value. If the parameter value is a one-digit number, it is rounded to one decimal place. If it is a two-digit number, it is rounded to a single digit, and so on; the filter current coil is expressed by the product of the inductance (H) and the square of the DC magnetizing current (mA). The parameter value uses three digits, of which the first two digits represent the two-digit significant figures after rounding, and the third digit represents the number of "0\". 3.5 Serial number When the product standard specifies the serial number, the Arabic numerals of the serial number are preceded by the Chinese pinyin "B", indicating a standard product. When the manufacturer numbers the products in sequence, "B" is not added to the serial number. 3.6 Specific examples: "TDB-120-B2" indicates a standard power transformer with an operating temperature level of B, a nominal power of 120V-A, and a sequence number of 2; "LEA-533-3\" indicates a non-standard filter with an operating temperature level of A, a magnetic field energy of 53X10°H·mA*, and a sequence number of 3.
4 Technical requirements and test methods
4.1 The environmental conditions for the use of components are divided into 6 strictness levels, see Table 2. t||Application range
Air pressure kPa
Ambient temperature
Constant damp heat d
Alternating damp heat d
Temperature change C
South growth d
Frequency Hz
Amplitude value mm
Number of sweep cycles per axis
Peak acceleration m/s2
Duration time
Number of times in each direction
Sign example
GB/T 15290—94
General indoor equipment
Ia-25/55
Note: ①The values ​​in brackets should not be used in new designs. ②Marking method of strictness level: Strictness level 4.2 Standard atmospheric conditions for arbitration test
25±1℃,
Relative humidity
48%~52%,
86~106kP.
4.3 Normal test atmospheric conditions||t t||Relative humidity
15~-35℃
45%~75%;
Pressure 86~106kPa
E-40/55
Portable mobile
Moving equipment
—40）
(—40)
55/Connect
Specified value
1-55/55
For ships
N-40/70
*-55/70
Select ambient temperature and low air pressure (service level V). 4.3.1 Unless otherwise specified in this standard, recovery, testing and inspection should be carried out under normal test atmospheric conditions. 4.4 Appearance and structure
4.4.1 Requirements
Aircraft equipment
25.7.5, 4, 2.1
According to Article 4.25
Specified values
10~500
The marking, external dimensions, installation dimensions and structure of the components shall comply with the provisions of the product standards, and the appearance shall not have rust, cracks or other mechanical damage; the coils, cores and accessories shall be firmly assembled. 4.4.2 Test method
GB/T 15290—94
Use a length gauge with an accuracy of not less than 0.02tn to check the external dimensions, installation dimensions and structural dimensions, and visually inspect the appearance and markings. 4.5 DC resistance
4.5.1 Requirements
The DC resistance of each winding of the component at a temperature of 20°C shall comply with the provisions of the product standard. 4.5.2 Test method
Measure with an ohmmeter or bridge with an accuracy of not less than Class 1. When the measuring ambient temperature is not equal to 20°C, it shall be converted according to formula (1). 254.5
234.5+6·R
In the formula, R2——DC resistance at a temperature of 20°C; R—DC resistance measured when the overflow is ?, n; 8—ambient temperature during measurement, ℃.
4.6 Winding Continuity
4.6.1 Requirements
Each winding subjected to environmental (mechanical, climatic) tests shall maintain electrical continuity. 4.6.2 Test Method
Measure with an ohmmeter or any other suitable device. When the windings are connected in parallel, the DC resistance (4.5) method shall be used for measurement.
4.7 Dielectric Strength
4.7.1 Requirements
The wire coil of the component shall not break down or arc over the core (or housing), electrostatic shield and each wire diagram when subjected to the test voltage specified in Table 3 within the test time.
Component severity level
.I, IN,
Line working voltage
36~250
>250~300
>100~500
: Except for specific provisions in this standard, the working voltage and test voltage refer to the effective value. Test voltage
2×line working voltage+1000
4.7.1.1 When the coil has a DC potential, the working voltage should be calculated according to formula (2). Uu.+
Where: -
Working voltage value, V,
Applying voltage time
（2）
U.—AC voltage value, V
DC potential value, V.
GB/T 15290—94
4.7.1.2 For some high-voltage coils, if the insulation thickness is reduced by considering its actual potential distribution, its test voltage can be specified after specific calculation. 4.7.1. 3 When it is necessary to determine the ability of the high-potential end of the coil to withstand the test voltage of the iron core (or shell) and other coils, the test should be carried out according to the induced voltage method 2 (1.8.2.2). During the test, the voltage multiple applied to the primary should make the voltage at the high potential end of the coil reach the value specified in Table 3, and the frequency should be increased to not less than the corresponding multiple. The lead-out end of the coil that is grounded during actual operation should be connected to the iron core (or shell). Note: ① The coil connected to the iron core (or shell) should also be tested in the above method. ② When the zero point of the line country rectification is not fixed, the two ends of the winding should be grounded in turn, and each test should be performed once in the above manner. 4.7.2 Test equipment
The capacity of the high-voltage test equipment should be not less than 0.5kV·A, and the instrument error indicating the test voltage value should not be greater than 5%. 4.7.3 Test method
4.7.3.1 Apply the test voltage between the test coil and the iron core (or shell) and the electrostatic shield, and the other coils are connected to the iron core (or shell) and the electrostatic shield. If the core of the component cannot be wired and there is no shell to connect (such as a toroidal transformer), it can be installed on the "casing" according to the actual use conditions, and the "casing" can be used instead of the core (or shell) for testing. 4.7.3.2 When the test voltage is above 2kV, the voltage should be gradually increased from zero to the specified value and maintained for the specified time, and then the test voltage should be gradually reduced to zero before the power supply is cut off. 4.8 Inductive voltage
4.8.1 Requirements
When the insulation of the component is subjected to twice the rated AC working voltage (the frequency is not less than twice the rated frequency) and a test time of 1min, its no-load current should not increase significantly (only method 1), and there should be no phenomenon such as hitting the air, flying, smoking or hot wire surroundings. Note: Components that have been tested according to the requirements of 4.7.1.3 or whose rated AC working voltage is less than 100V are no longer subject to this test. 4.8.2 Test method
4.8.2.1 Method 1 As shown in Figure 2a, open the other coils of the component and apply the specified voltage to the test coil. 4.8.2.2 Method 2 As shown in Figure 2b, open the other coils of the component, and connect the grounding terminals of the component when it is working (when there is no fixed grounding terminal, any end of the coil can be used) to the iron core or shell and the electrostatic shield, and then connect to any end of the test coil. At the same time, it should be noted that the common ground of the test component is connected to the "ground" terminal of the voltage regulator, and apply a specified positive voltage F to the test coil. In the figure: F fuse:
-adjustable self-difficult transformer,
T, - Test component (taking transformer as an example): A--AC ammeter with an accuracy of not less than 2.5; -AC voltmeter with an accuracy of not less than 2.5. Figure 2
4.9 Insulation resistance
4.9.1 Requirements
GB/T 15290—94
The insulation resistance of each coil of the component to the core (or shell), electrostatic shield and each coil shall not be less than the requirements of Table 4. Table 4
Component Strictness Level
Irrigation Measurement State
High Temperature Minimum
4.9.2 Test Method
, I, I,,
4.9.2.1 Use an insulation resistance tester or megohmmeter, shaker, and apply a DC voltage of 100V (working voltage not greater than 36V) or 500V (working voltage greater than 36V). If the core of the component cannot be connected and there is no shell to connect (such as a toroidal transformer), it is installed on the "casing" in the actual use state, and the "casing" is used instead of the core or shell for testing. 4.9.2.2 For components with non-potting and cast structures that are not packaged or simply packaged, pretreatment can be performed before measuring the normal insulation resistance. Pretreatment method: clean the dust on the surface of the component, then put the component into an oven at 80±5℃ (Y grade) or 100±5℃, keep it for the time specified in Table 5, take it out of the oven, and place it in normal atmospheric conditions for 48h. 4.10 No-load characteristics
4.10.1 Requirements
When the secondary of the transformer is open and the rated voltage of the rated frequency is applied to the primary, the no-load current, no-load loss and no-load voltage error shall comply with the product standard.
4.10.2 Test method
The test circuit and method shall be in accordance with Appendix A (supplement). 4.10.2.1 During measurement, the power supply frequency error shall not be greater than 1%, the power supply voltage harmonic distortion shall not be greater than 5%, and the three-phase voltage imbalance (based on the lowest phase voltage adjusted to the test voltage rating) shall not be greater than 1.5%. 4.10.2.2 When the power supply frequency error exceeds the allowable range, the no-load current and no-load loss shall be measured according to formula (3) to determine the test voltage, and the measured no-load loss value shall be corrected according to formula (4). Ur=
Wherein: f-rated frequency, Hz;
f\——actual frequency, Hz1
U——rated test voltage, V;
\—changed test voltage, V
corrected no-load loss of the tested transformer, W; Wherein P.
GB/T15290:94bzxZ.net
P'—actual no-load loss of the tested transformer before correction, W-correction coefficient. For 50 Hz, 400 Hz power supply, K value can be found from Figure 3. K-
4.10.2.3 If the unbalance of the two-phase power supply voltage is within the allowable range, when measuring the no-load current and no-load loss, the lowest phase voltage should reach the rated value of the test voltage.
4.11 Inductance minimum
4.11.1 Requirements
The inductance of the current-casting coil shall comply with the requirements of the product standards under the conditions of rated magnetizing current and rated AC voltage at rated frequency. 4.11.2 Test method
A bridge that can add rated conditions to the choke or the circuit shown in Figure 1 should be used to measure the inductance F
In the figure: Ci, Cz---metal film or polyester capacitors, usually 50uF, 100V, when the inductance of the choke to be measured is small, the capacity of CtC, should be appropriately increased to make XXLi. The working voltage of Ci.C2 at this time should be selected according to actual needs; T,--adjustable autotransformer,
T... isolation transformer,
fuse,
precision 2.5 level electronic tube or product tube millivoltmeter: V,---precision 2.5 level effective value voltmeter, A-precision 1 level magnetoelectric DC ammeter: Measured choke:
choke, the choke to be measured can be used:
GB/T 15290—94
DC power supply, whose ripple voltage is not greater than 3% of the AC test voltage, R-resistance with precision of level 1, whose resistance value is selected according to formula (5), and the resistance value is measured by bridge. 2nfLx
Where: K—resistance value of resistor, a:
at—frequency of AC test voltage, Hz;
—inductance of the measured current rejection diagram, H.
4.11.2.1 When using the circuit of Figure 4, it is allowed to use AC power supply with different rated frequency for testing, but the difference between the actual frequency and the rated frequency shall not exceed 10%, and the test voltage shall be determined according to formula (3) of 4.10.2.2. 4.11.2.2 When measuring inductance, first adjust the DC power supply so that the reading of ammeter A is the rated value, then apply AC voltage so that the reading of millivoltmeter V, is the test value - then read the effective value of millivoltmeter V, and calculate the inductance according to formula (6). R
2 yuan f,
In the formula: Lx-
The inductance of the measured repellent coil, H,
f——Frequency of AC test voltage, Hz
R-—Resistance, α;
-The indicated value of millivoltmeter V, V;
U,—The indicated value of millivoltmeter V, V.
4.12 Electrostatic shielding
4. 12.1 Requirements
For transformers with requirements for electrostatic shielding effect, its electrostatic shielding factor shall meet the requirements of product standards. 4.12.2 Test method
Use the circuit shown in Figure 5 for measurement.
-Tube or transistor milliohmmeter with an accuracy of 2.5: In the figure. V, v,
(audio signal generator)
T...transformer under test;
S-single-pole single-throw switch,
QI-primary coil of transformer under test;
dielectric coil of transformer under test.
GB/T1529D—94
4.12.2.1Disconnect switch S, adjust the frequency of the audio signal generator to 20kHz,And adjust the audio signal output so that the indication value of the voltmeter V is 100V, and record the indication value of the voltmeter V. 4.12.2.2 Close the switch S, adjust the audio signal output, and keep the indication value of the voltmeter V unchanged. Then record the indication value of the voltmeter V, and calculate the shielding factor K by formula (7).
In the formula, Uz—the indication value of the voltmeter V when the switch S is open, V; U22—the indication value of the voltmeter V when the switch S is closed, V. 4.13 Magnetic radiation
4. 13.1 Requirements
For components with limited magnetic radiation requirements, the impact of their magnetic radiation on the surrounding environment should not be greater than the provisions of the product standard. 4.13.2 Test method
Perform in accordance with the provisions of Articles 4, 4, 21, and 3 of GB 8554. 4.14 Noise
4.14.1 Requirements
For components with limited noise requirements, the noise level should not exceed the requirements of the product standards. 4.14.2 Test method
Perform in accordance with the requirements of SJ2488 standard.
4.15 Temperature rise
4.15.1 Requirements
Under rated load conditions, the measured temperature rise value of the component should not be greater than the difference between the allowable operating temperature and the upper ambient temperature; components with a strictness level of " should be tested at the upper ambient temperature. Note: The allowable upper operating temperatures for different operating severity levels are shown in Table 1; the upper ambient temperature is shown in Table 2. 4.15.2 Test method
The test circuit and method are in accordance with Appendix B (Supplement). 4.15.2.1 The holding time required for the temperature rise to reach a stable value is specified in Table 5. Table 5
Component weight
>0. 2 ~~0. 5
>0. 5 ~1. 5
Holding time
Component weight
2-13-~18
>18--25
>25~40
Holding time
If the power supply frequency error exceeds the allowable range, the primary voltage should be determined according to 4.10.2.2 and the load current should be kept at the rated value. 4. 15. 2. 2
For components with severity level Ia, check the insulation resistance (4. bars) immediately after measuring the temperature rise. 4. 15. 2. 3
4.16 Load characteristics
GB/T15290-94
4.16.1 Requirements
After the temperature rise of the transformer reaches a stable state under rated load conditions, the error of the voltage of each secondary line diagram should not be greater than the provisions of Table 6. For a coil with a center tap, the voltage asymmetry (i.e. the difference between the voltages on both sides divided by the sum of the voltages on both sides) should not be greater than 4%. Table 6
Energy group voltage, V| |tt||4.16.2 Test instrument
The requirements for test instrument are the same as those in 5.10.
4.16.3 Test method
Allowable error, %
Can be carried out simultaneously with the temperature rise test. When the temperature rise of the transformer is stable, measure the load voltage first and then the temperature rise. 4.17 Corona discharge
4.17.1 Requirements
Strictness level I, , 【, V, V and other components After the high temperature test, when the test voltage is 1.12 times the line voltage, there should be no corona discharge phenomenon.
4.17.1.1 For some high-voltage coils, the insulation thickness is reduced due to the actual potential distribution. The corona discharge test between coils or between the line and the core (or outer shell) can be calculated and specified according to the actual potential distribution. 4.17.1.2 Components with coil working voltage lower than 300V are not subject to this test. 4.17.2 Test method
Perform the method specified in Appendix A of GB8554. 4.18 Overload
4.18.1 Requirements
The transformer should not burn or be damaged under continuous overload conditions. Transformers that do not undergo this test should be stated in the product standard. Note: Transformers with a measured temperature rise of no more than 30K or working under a power supply voltage change of no more than +5% do not need to undergo overload test. 4.18.2 Test method
4.18.2.1 Place the transformer at the upper ambient temperature specified in Table 2, the temperature error is not greater than 2°C, and the continuous load is 8b. 4.18.2.2 When using the direct load method, first put the transformer at the rated load state, and then increase the primary voltage to 1.12 times the rated value. When using the docking load method, in addition to adjusting the primary voltage to 1.12 times the rated value, the load current should also be adjusted to 1.12 times the rated value. 4.18.2.3 If the power supply frequency error exceeds the allowable range, the primary voltage should be determined according to 4.10.2.2, and then increased to 1.12 times on this basis.
4.18.2.4 After continuous load for the specified time, restore under normal atmospheric conditions for a time not less than that specified in Table 5, and then conduct the following inspections:
Appearance and structure (Article 4.4);
Induced voltage (Article 4.8 Method 1);
c. No-load current (Article 4.10).
4.19 Solderability
4. 19.1 Requirements
The lead-out terminals of the components to be connected by soldering, the areas to be wetted by the solder should be easily wetted by the molten solder. For test method 1, the impregnated surface should be covered with a smooth and clear solder layer, and only a small amount of scattered defects such as pinholes, non-wetting or weakly wetting areas are allowed, and these defects should not be concentrated in one place; for test method 2, the solder should wet the test surface area and there should be no droplets. 4.19.2 Test method
GB/T1529094
Perform according to 4.6 (method 1) or 4.7 (method 2) of GB32423.28 standard. 4.19.2.1 The surface of the component to be tested should be the same as the "just received" condition, and should not be touched or otherwise contaminated thereafter, and should not be cleaned before the test.
4.19.2.2 Test method 1 Solder slot method) Components directly mounted on the printed circuit board are welded by the soldering method. After the test, use a 5x magnifying glass to check the undamaged surface.
4.19.2.3 Test method 2 (molten iron method) Components with lead terminals soldered by a soldering iron during installation use the soldering iron method. Components with a mass greater than 2kg use soldering iron A, and components with a mass less than 2kg use soldering iron B. After the test, use a 5x magnifying glass to check the lead terminal test surface. 4.20 Resistance to welding heat
4. 20.1 The lead terminals of the components to be connected by soldering shall have no mechanical damage on the appearance after being subjected to the thermal stress generated by the test, and the windings shall remain continuous. 4.20.2 Test method
The test shall be carried out in accordance with 5.4 (method 1) or 5.6 (method 2) of GB2423.28. 4.20.2.1 Test method 1 (solder bath method) The components directly mounted on the printed circuit board shall be immersed in the solder bath method for a specified time at the specified depth: 5 ± 1s for components with heat-sensitive components, generally The test time of the lead-out terminal and the parts and windings related thereto is 10 ± 1s. After the test, the appearance and structure (Article 4.4) and the continuity of the winding (Article 4.6) are checked. 4.20.2.2 Test method 2 (soldering iron method) When installing, the lead-out terminal components are soldered with a soldering iron using the molten iron method. For components with a mass of less than 2kg, molten iron A is used. For components with a mass of less than 2kg, baked iron B is used. After the test, the lead-out terminal and the parts and windings related thereto are checked for appearance and structure (Article 4.4) and the continuity of the winding (Article 4.6). 4.21 Lead-out Terminal Strength
4.21.1 Requirements
After the lead-out terminals of the components are subjected to mechanical stress, the appearance shall be free of mechanical damage and the winding shall remain continuous. 4.21.2 Test Method
Perform the test in accordance with the relevant provisions of Chapter 1, Chapter 2 and Chapter 5 of GB2423.29. 4.21.2.1 Test Method 1 For components with potting or casting structure as the main body (excluding soft lead-out terminals), the linear lead-out terminals (circular cross-section or strip-shaped) shall be subjected to tension test and thrust test, and the direction of force is shown in Figure 6. After the test, the lead-out terminals and the related parts and windings shall be inspected for appearance and structure (Article 4.4) and winding continuity (Article 4.6). Tension
4.21.2.2 Test method 2 For components with general structure (including potting, injection-molded structure as the soft lead-out terminal of the main body), the linear lead-out terminals (circular cross-section or strip-shaped) shall be subjected to tension test, and the force direction is shown in Figure 6. After the test, the lead-out terminals and the related parts and windings shall be inspected for appearance and structure (Article 4.4) and winding continuity (Article 4.6). 4.21.2.3 Test method 3 Torque test shall be performed on the lead-out terminals or screw lead-out terminals. After the test, the lead-out terminals and the related parts and windings shall be inspected for appearance (Article 4.4) and winding continuity (Article 4.6). 4.22 Low pressure
4.22.1 Requirements
..GB/T 15290--94
The components shall be able to withstand the test voltage specified in Table 7 without breakdown and flashover under low pressure conditions. Table 7
Strictness level
Test pressure, kPa
As specified in the strictness level mark (Note ② in 4.1):
25±0.125, 7.5±0,0075
4 + 0. 004, 2±0. 002
Test voltage
As specified in 4. 7.1
1. 25 times the working voltage
4.22.1.1 For high-voltage coils with reduced insulation thickness in consideration of the actual potential distribution, the test voltage may be specified after specific calculation. 4.22.1.2 Coils with a maximum DC potential lower than 150V or a working voltage lower than 100V are not subject to this test. 4.22.2 Test method
Place the component in a low-pressure box, reduce the pressure in the box to the value specified in Table 7, keep it for 5 minutes, and then conduct the electric strength test (4.7) in the box. Other tests shall be conducted in accordance with the relevant provisions of GB2423.21. 4.23 Vibration
4.23.1 Requirements
The component should be able to withstand the vibration specified in Table 2, and its appearance, structure and electrical properties should still meet the requirements. 4.23.2 Test method
According to the relevant provisions of (B2423.10 standard 4.23.2.1 Strictness level 1a, I, I, ear, IV and other components, the mass is not more than 2kg should be tested in three mutually perpendicular directions formed by its axis; the mass is greater than 2kg, it should be tested in the direction according to the actual working fixation method. 4.23.2.2 Strictness level V components should be tested in three directions. 4.23.2.3 After the vibration test, the following inspections shall be carried out: a. Appearance and knot tree (4.4);
Winding continuity (4.6);
No-load current or inductance (4.10 or 4.11). 4.24 Collision
4.24.1 Requirements
The component should be able to withstand the collision specified in Table 2, and its appearance, structure and electrical properties should still meet the requirements. 4. 24. 2 Test method
The test is to be conducted in accordance with the relevant provisions of GB2423.6. 4.24.2.1 For components with severity levels of 1a, 1,,, N, etc., the weight of which is not more than 2kg, the test shall be conducted in three mutually perpendicular directions formed by its axis. For components with a weight of more than 2kg, the test shall be conducted in · directions according to the actual fixing method during operation. 4.24.2.2 For components with severity level of V, the test shall be conducted in three directions. 4.24.2.3 After the impact test, the following inspections shall be conducted: a.
Appearance and structure (Article 4.4);
Winding continuity (Article 4.6);
zNo-load current or inductance (Article 4.10 or 4.11). 4.25 Temperature change
4.25.1 Requirements
For components with severity levels of 1,,,, N, etc., after undergoing 5 consecutive temperature change tests, their appearance and structure shall still meet the requirements.
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