Voltage tolerance of safety capacitor

X capacitors and Y capacitors are common capacitors in safety capacitors. At the input end of AC power, three safety capacitors are generally added to suppress EMI conduction interference. They are used in the power filter and act as a power filter. For common mode, differential mode workers interfere with filtering. How should this capacitor be used? I'll talk to everyone below.

Generally, the X capacitor is connected in parallel between the hot line and the neutral suppression. According to actual needs, the capacitance of the X capacitor can be larger than the capacitance of the Y capacitor, but in this case, a safety resistor must be connected in parallel across the X capacitor. The charging and discharging process of the capacitor causes the plug of the power cord to be charged for a long time to prevent the electric shock from occurring when the power cord is plugged in or out.

The general Y-capacitor is connected between the live line and the ground line and between the neutral line and the ground line. Under normal circumstances, working in subtropical machines, the required leakage current to ground cannot exceed 0. 7mA; work in temperate zone. The machine requires that the earth leakage current can not exceed 0. 35mA. Therefore, the total capacity of Y capacitors cannot exceed 4700 PF. Because the location of these two capacitors is very critical, be sure to choose qualified safety certified capacitors! Preventing electrical equipment from leaking electricity or energizing the case can easily endanger personal safety and life.

The peak pulse voltage allowed in the safety grade of the safety capacitor is overvoltage level: X1> 2. 5kV ≤ 4. 0kV, X2 ≤ 2. 5kV, X3 ≤ 1. 2kV, Safety Capability Safety Rating Insulation Type Rated Voltage Range Y1 ≥ 250V , Pressure 8KV; Y2 ≥ 150V ≤ 300V, pressure 5KV.

The problem that the editor receives from the customer is that it needs to withstand surge voltage peaks of 2000V. Now that we have used 0. 1μF X capacitors and 2200pF Y capacitors, what should the withstand voltage of these capacitors be at least? DC voltage withstand voltage of 100V and 250V capacitors. Can these capacitors withstand surges?

For example, if a 220V system is used, the safety capacitor of 275V is selected, the 380V system is selected as 440V or the series connection is 2 275V, and the surge is less than 2.5KV so that the X2 capacitor is selected. Here are some special points to make: 1 can not use ordinary capacitors instead of safety capacitors, safety certification must be certified safety capacitors, which is responsible for life! 2 Safety capacitors are generally marked with pressure proof, but their true DC withstand voltage is much higher than the marked pressure resistance (marking 250V withstand voltage up to 2KV). Therefore, do not use the rated withstand voltage freely when using. An ordinary capacitor like the safety capacitor is used instead, and the capacitor must be certified.