1. Repeated Short Circuit Test Test Instructions: The module's output should be short-circuited under various input and output conditions. The module must be capable of protecting itself or retracting, and it should withstand repeated short circuits. Once the fault is removed, the module should automatically return to normal operation. Test Methods: a. No Load to Short Circuit: Within the full range of input voltage, the module should transition from no load to a short circuit, with proper current limiting or retraction. After removing the short, the module should resume normal operation. Repeat this process for 2 hours, with 1 second of short circuit and 1 second of release each time. Afterward, check if the module operates normally. b. Full Load to Short Circuit: Under full input voltage range, the module should limit current or retract when transitioning from full load to a short circuit. After the short is removed, the module should return to normal operation. Keep the module in a shorted state for 2 hours, then release and check its functionality. c. Short-Circuit Boot: Short the module’s output, then power on the input voltage within the module’s specified range. The module should respond with proper current limiting or retraction. After the short is removed, it should return to normal. Repeat this test 10 times and verify that the module functions correctly after the final test. Judgment Standard: After the test, the power module should start up properly. Check the boot case, board, and components for any abnormalities (e.g., stuck relays during short circuits). If all conditions are met, it is qualified; otherwise, it is unqualified. 2. Repeated Switch Test Test Instructions: When the power module is at maximum load, apply input voltages of 220V, 5V below the overvoltage point, and 5V above the undervoltage point. Repeatedly switch the input to test the module's performance during repeated on/off cycles. Test Methods: a. Input voltage is set to 220V, and the module is operated at maximum load. Use a contactor to cycle the input voltage on for 15 seconds and off for 5 seconds. Continue this for 2 hours and ensure the module works normally. b. Input voltage is set to 5V below the overvoltage point. Operate the module at maximum load and repeat the same cycling process for 2 hours. c. Input voltage is set to 5V above the undervoltage point. Again, operate the module at maximum load and perform the same cycling test for 2 hours. Judgment Standard: If the module operates without issues throughout the test and shows no significant changes in performance, it is considered qualified. Otherwise, it is unqualified. 3. Input Undervoltage Cycle Test Test Instructions: This test simulates situations where the input voltage drops close to the undervoltage threshold, causing the module to disconnect. After the load is removed, the voltage may rise again, potentially causing repeated low-voltage events. This test ensures the module can handle such scenarios without failure. Test Methods: Run the module at full load while slowly varying the input voltage between 3V below and 3V above the undervoltage point. This cycle should last 5–8 minutes and be repeated continuously for at least 0.5 hours. The module should remain stable and functional throughout. Judgment Standard: If the module continues to operate normally for at least 0.5 hours without significant performance degradation, it is qualified. Otherwise, it is unqualified. 4. Input Transient High Voltage Test Test Instructions: This test evaluates the module's stability under transient high-voltage conditions, particularly for modules with PFC circuits. It helps assess the reliability of the protection mechanisms and overall design. Test Methods: a. At rated voltage, use an oscilloscope to monitor the input voltage and overvoltage protection signal. Apply a 5V jump to 300V and record the number of 300V cycles before the protection activates. b. Apply 300V voltage jumps to the input at full load for 3 hours, using (n-1) cycles at a frequency of 1 per 30 seconds. Judgment Standard: If the module remains stable and shows no damage or abnormal behavior under these conditions, it is qualified. Otherwise, it is unqualified. 11mm and 3mm Spring Steel Wire,compression spring,tension spring,torsion spring,wire forming Yixing Steel Pole International Trading Co., Ltd , https://www.yx-steelpole.com