Do edge computing boxes need to undergo voltage fluctuation and flicker testing?

Edge computing boxes typically have a rated power of less than 1kW. According to GB17625.2 (IEC61000-3-3 standard), voltage fluctuations caused by starting or stopping every 5 minutes should be Pst < 1.0, Plt < 0.65, dmax < 4%, and d(t) > 200ms. If the edge box uses a soft-start power supply or a built-in UPS with a large capacitor, surge currents may occur during charging, causing short-term voltage drops. Therefore, testing and preventative measures are necessary. An NTC thermistor MF72 5D-9 (named MF72 series 5D, rated resistance 5Ω 25℃, D disc 9, diameter approximately 10mm) is connected in series at the AC input to suppress start-up surge currents. Combined with relay delay bypass, this reduces steady-state power consumption. Simultaneously, a varistor 14D511K (named 14D, diameter 14mm, 511, varistor voltage 510V) is connected in parallel at the input. A standard type absorbs overvoltage during switch operation. Actual testing showed that after adding the NTC, the voltage fluctuation Pst decreased from 0.8 to 0.3, meeting the requirements of GB17625.2. Therefore, the design of edge boxes, especially high-power models, needs to assess the risk of voltage flicker.