How can the safety capacitors of intelligent low-voltage monitoring units balance EMC and safety requirements?

Safety capacitors must be correctly selected and placed to balance EMC and safety requirements. The X capacitor is a CY-X2-474K (0.47μF/305V), connected between L and N for differential-mode filtering, and is UL and CE certified. The Y capacitor is a CY-Y1-222K (2.2nF/250V), connected between L/G and N/G for common-mode filtering, meeting Y1 level (8kV surge). PCB layout: The safety capacitors are placed at the power input, forming a filter network with the common-mode inductor CMZ3225A-501T. Safety distances: The primary-secondary spacing is greater than 6mm, and the creepage distance is greater than 5mm. This design reduces conducted emissions by 30dB while meeting IEC 60950-1 safety insulation requirements (2500VAC withstand voltage).