Safety Capacitor X Capacitance and Y Capacitor Selection Method

Safety capacitors are well known because of their high safety. The electronic component market is one of the indispensable capacitor products. Today, the editor shared with you the selection method of the safety capacitor X capacitor and Y capacitor. Safety capacitors are used in applications where the capacitor does not cause an electric shock and does not endanger personal safety. It includes X and Y capacitors. The X capacitor is a capacitor that is connected between the two lines of the power line (LN). Generally, a metal film capacitor is used. The Y capacitor is a capacitor that is connected between the two lines of the power line and the ground (LE, NE), and is generally in pairs. . Based on the limitation of leakage current, the value of Y capacitor should not be too large. Generally, the X capacitor is uF grade, and the Y capacitor is nF grade. The X capacitor suppresses differential mode interference and the Y capacitor suppresses common mode interference.

Safety capacitor safety class, insulation type, rated voltage range:

Y1 double insulation or reinforced insulation ≥250V

Y2 basic insulation or additional insulation ≥150V≤250V

Y3 basic insulation or additional insulation ≥150V≤250V

Y4 basic insulation or additional insulation <150V

The capacitance of the safety capacitor Y capacitor must be limited to achieve the purpose of controlling the leakage current flowing through it under the rated frequency and rated voltage and the impact on the EMC performance of the system. The capacity of the commonly used Y capacitor should be no more than 0.1uF. In addition to complying with the corresponding grid voltage withstand voltage, the safety capacitor Y capacitor also requires sufficient safety margin for electrical and mechanical performance to meet the IEC 60384-14 international standard. To avoid breakdown and short circuit under extreme environmental conditions, the pressure resistance of Y capacitor is important for protecting personal safety.