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CE certification introduction:
The "CE" mark is a mandatory certification mark. Whether it is a product produced by a company within the EU or a product produced in other countries, it must be affixed with the "CE" mark to show that the product complies with the EU's requirements if it wants to circulate freely in the EU market. The basic requirements for the new method of technical coordination and standardization. This is a mandatory requirement imposed by EU law on products. The word CE is an abbreviation of the French "Communate Europpene" and means the European Community.
CE certification test preparatory work:
Due to the lack of CE certification testing and the lack of CE certification testing experience in the past, the pre-preparation work in this CE certification test did not do a full or a bit, resulting in unsatisfactory progress in the certification testing process, affecting the certification testing cycle. Therefore, in order not to affect the test cycle, the preparatory work needs to be done more carefully and needs to be done together with the developers. The preparatory work for the CE certification test is summarized below:
1, need the developer to assist in preparation:
(1) Gather certification materials for key device lists and key devices;
(2) Provide the schematic diagram of each board of the test prototype;
(3) Provide isolation transformer samples;
(4) Provide PCB light board;
(5) Provide CE test prototypes.
2, the need for testers to prepare:
(1) Can provide Chinese and English user manuals, Chinese and English installation manuals (must have English user manuals);
(2) Submit CE certification test application and Chinese and English user manuals in the company's reliability park;
(3) It is necessary to prepare a nameplate with a CE mark and the nameplate mark meets the requirements;
(4) Testers need to pre-test the weak items of the prototype for the test requirements, and inform the developers in case there are no items.
Rectification
(5) Check whether the list of key components provided by the developer includes all, and check whether the key component's certificate number is correct or not.
The object matches, and if there is any omission or inconsistency, the developer will be informed immediately of the change.
3. Test content
CE certification test content includes EMC test and safety test two major types of test items, usually the first EMC test, after passing the test and then the safety test, after the completion of the two tests, safety testers to provide CE certification.
EMC test:
EMC test items to be tested include: conducted disturbance test, radiation disturbance test, electrostatic discharge immunity test, conducted immunity test, radio frequency electromagnetic field radiation immunity test, electrical fast transient burst immunity test, voltage transient Drops and short-term interruptions Interference immunity test, input current harmonics test, surge immunity test, power frequency magnetic field immunity test, etc.
Safety test:
Safety test is the focus of CE certification test, it is also a test difficulty, the test content is more, safety requirements and the requirements of GB4943 standard requirements are similar, the test content is as follows:
1. Nameplate, label permanent test:
Test method: Wipe the tag for 15 seconds with soapy water or gasoline and then check the nameplate and label.
Judgment criteria: The nameplate and label do not fall off.
2. Input current test:
Test method: Test the maximum input current of the prototype in mains mode, test it at full load and under low voltage and heavy load.
Criterion: The requirement is not greater than 110% of the nominal input current value.
3. Capacitance discharge test of the main circuit:
Test method: Use an oscilloscope to test the voltage of the capacitor with a high-voltage probe. Disconnect the input voltage at the peak of the highest input voltage. Use an oscilloscope to measure the time when the voltage drops from the highest value to the safe voltage. If there is a settable fixed phase break, Electric AC SOURCE is best. If not, it can only be repeated several times until the power-off phase is 90 degrees or 270 degrees.
Criterion: Within a time constant (<1s), the voltage drops below 37% of the input voltage.
Note: No need to test X capacitor capacitance < 0.1μF.
4. Protection test:
Test Methods:
1) Apply DC voltage to both the output ground and the input ground. At the same time, connect the current meter to the line, start the DC voltage from 0, and gradually increase, so that the current of the current meter will gradually reach 25 ampere for 1 minute, and then according to the voltage and current value. Calculate the resistance of the output ground and input ground;
2) Apply a DC voltage across the metal housing and the input ground. Connect the current meter to the line. Start the DC voltage from 0 and gradually increase the current. The current of the current meter will gradually reach 25 amps for 1 minute, and then according to the voltage and current values. Calculate the resistance of the output ground and input ground;
3) Apply a DC voltage across the ground and the input ground of the PCB board. At the same time, connect the current meter to the line, start the DC voltage from 0, and gradually increase, so that the current of the current meter will gradually reach 25 amps for 1 minute, and then The voltage and current values calculate the resistance of the output ground and input ground;
Criterion: The voltage drop across the protective connecting conductor is not more than 2.5V, ie the grounding resistance is less than 0.1Ω.
5. Compressive strength test:
Test method: Before the test, the prototype was placed in a 20-30C, 91-95% RH environment and stored for 48 hours before the following withstand voltage test was performed.
1) Between the input line and the communication serial port, using a voltage tester, set the voltage DC to 4242V
2) Input zero live line to ground, use voltage tester, set voltage DC to 2121V
3) Output zero fire line to ground, with voltage tester, set the voltage DC to 2121V
4) The original secondary side of the isolation transformer, tested with a voltage tester, set the voltage exchange to 3000V
Criterion: No breakdown of insulation when tested for compressive strength.
6. Single point of failure test:
Test method: Select the key components on each board to make these components short-circuit or open circuit before or after booting. Observe and record whether the prototype is damaged and what other components are damaged. Each component performs a single point of failure test alone. As to how to select the right single point, you need to have a relatively familiar understanding of the schematics, components, European standards, and other relevant data before you can do it. These are also a long-term process that has accumulated in practical work.
Judging Criteria: No fire, no insulating device can be damaged, no molten metal liquid can splash out, and electrical strength test must be passed.
7. Critical temperature rise test:
Test method: Select key components such as main board, power board, auxiliary power board, and charger board, and test the temperature of each component under the conditions of full load and different input voltages using a temperature riser. These components are mainly: capacitors, switches, inductors, radiators, switches, wires, relays, transformers, batteries, PCB.
Criterion: Not greater than the nominal temperature of the component.
8. Leakage current test: prototype is normal, the input voltage is the maximum input voltage
1) Test the leakage current of the input neutral line to the communication port with a leakage current tester
2) Use a leakage current tester to test the leakage current of the input fire line to the communication port
3) Use a leakage current tester to test the leakage current of the input zero line to the metal case
4) Use the leakage current tester to test the leakage current of the input fire wire to the metal shell
5) Test the leakage current of the input neutral line to the plastic panel with a leakage current tester
6) Use a leakage current tester to test the leakage current of the input fire wire to the plastic panel
Criteria: Class I: <3.5mA required
9. Clearance and creepage distance measurement test:
Test method: First measure the primary and secondary side working voltage value, and then according to GB4943 look-up table method according to the input voltage rms value and working voltage value to check whether the following safety distance meets the requirements:
1) Creepage distance and clearance between the circuit and the shell (protective ground) at one time.
2) The creepage distance and clearance between the two circuits of the safety circuit are measured once.
Judgment criteria: The safety distance specified in GB4943 standard is the standard.