As people pay more and more attention to the quality of life, they have higher and higher requirements for the quality of products. Every component used in electronic products should be carefully considered; Just like connectors, they need to pass many tests to make them have long-term and stable use effects. Some certifications are technical specifications and standards. For example, connectors have UL certification, ROHS certification, reach certification, etc. a few professional manufacturers will have these certifications. For example, Xiaobian today will talk about the tests of UL certification, Let everyone know more about high-quality connectors.
1. Accelerated aging test: it mainly tests the products containing rubber and PVC materials in the connector. Its test condition is that the product is put into an airy oven, and the temperature in rubber’s oven is 100 ± 2 ° C for 70 hours; The oven temperature of PVC is 100 ± 1 ° C for 96 hours. There is no deformation on the appearance after taking out, and the hardness change shall not exceed 10 points. If the product has plastics of multiple colors, it shall be made for each color.
2. Injection stress release test: test conditions: ① all connectors shall be installed into finished products without mutual cooperation; ② the minimum temperature shall not be lower than 70 ° C and higher than the maximum working temperature specified by the customer (but not higher than the RTI value of plastic) or the maximum temperature of temperature rise test. Both temperatures are 10 ° C higher. Test results: the product shall not have any distortion, shrinkage or other deformation. This test is not required for thermosetting materials.
3. Overload test: test conditions: ① the current used in the test is 1.5 times of the rated current of the product. ② the test voltage is within the range of 95% – 105% of the rated voltage of the product (the voltage given when the current is AC is between 75% – 80% of the rated voltage of the product). ③ a grounding fuse is connected during the test. The specification of the fuse is determined by the rated current of the product. When the rated current of the product is less than 30a, a 15A fuse is selected; When the rated current of the product is > 30a, 30A fuse shall be used. The test method is live plugging for 50 times, and the plugging frequency per minute is < >
4. Temperature rise test: test requirements and results: ① distribution point: the temperature rise test point shall be arranged at the terminal. When the contact terminal of the product has crimping and plate connection, the crimping terminal can be replaced by the plate connection terminal. ② all terminals with the same current must be connected in series into a loop to connect the same current. ③ test with the smallest wire diameter and the largest number of terminals in series. ④ the ambient temperature of the test is 25 ± 5 ° C. ⑤ when multiple terminals of the product have different currents, the test circuit of each terminal needs to be separated and carried out at the same time. ⑥ the maximum temperature tested shall not exceed the RTI value of plastic materials. ⑦ the test time is 4 hours. When the temperature rise data is the last 15 minutes, it shall be read every 5 minutes, and the three consecutive readings shall be consistent. ⑧ products of typo 0 and typo 1A can be exempted from temperature rise test without specifying current.
5. Withstand voltage test: test requirements: ① it must be tested immediately after the temperature rise test. (i.e. resistance to high voltage under hot condition) ② during the test, the nearest part between the charged body contacts shall be selected for measurement. ③ it shall be measured between the electrified body and the exposed non electrified metal and between the body and the shell. ④ the test voltage is generally AC. if DC is used, 1.414 times of AC must be used. ⑤ voltage withstand test is not required for typo 0 products. ⑥ typo 1b type products adopt Ac500V. ⑦ typo 1A 2 3 4 type products shall be 1000 V plus twice the rated voltage of the product. ⑧ typo 5 type products shall meet the requirements of corresponding finished product standards, but the minimum voltage shall not be less than 2200v. Test results: the product can withstand the corresponding voltage for 1 minute without being broken down by arc.
6. Arc resistance test: the test conditions are the same as the overload test, and more plugging and plugging are required for 200 times. Arc resistance test is mainly aimed at insulating materials. After the test, the product plastic is not allowed to be ignited and permanent carbon marks are not allowed. Arc resistance test shall be conducted after overload test, temperature rise test and voltage resistance test, and all need to be the same sample.
7. Tension test: ① test the crimping terminal with only one needle. ② the tensile force borne shall comply with the comparison table of line and force. ③ during the test, it can bear the relative tensile force for 1 minute, and it is not allowed to fall off.
8. Grounding impedance test: test conditions: ① the test current is 40a, and the test voltage is ≤ 6V 60Hz under no load for 2 minutes. Test results: the impedance does not exceed 0.1 Ω. Which products need to be tested for grounding impedance: ① connectors with grounding terminals have clear grounding symbols on the products. ② the product has terminal metal shell and fixed metal parts. ③ grounding most of the metal is connected with terminal.
9. Combustion test: the main standard of combustion test is UL94, which is mainly divided into two test methods: ① horizontal combustion test (the test result can reach Hb level after passing) ② vertical combustion test. (the combustion grade can be divided into V-2 V-1 V-0 5VA 5vb) 12mm flame combustion test conditions: ① store it in the temperature conditions of injection stress release test for 7 days. ② take it out and put it in an environment with a temperature of 23 ° C ± 2 ° C and a humidity of 50 ± 5 for 4 hours. ③ use a flame with a height of 12mm, burn twice for 30 seconds, and the interval between each combustion is 1 minute. ④ the sample length of combustion test is generally 35mm and the thickness is 0.5mm. ⑤ the gas used in the combustion test is butane. ⑥ after the flame leaves, the combustion shall not exceed 1 minute. After passing the test, the flame retardant grade reaches V-2 or above.
15A fuse shall be selected at 30A; When the rated current of the product >