MKP62 305V X2 225k Film Capacitor for Interference Suppression

MKP62 305V X2 2.2µF (225K) Film Capacitor – ASIC PSU EMI Filter / Interference Suppression

The MKP62 305V X2 2.2µF (225K) film capacitor is the across-the-line (X2-class) safety capacitor sitting in the AC input EMI filter of mining PSUs. Rated for direct connection between the live and neutral conductors at 305VAC, it suppresses high-frequency switching noise generated by the PSU's primary stage from re-entering the mains, and rejects mains-borne transients from coupling into the PSU. X2-class construction is mandatory by safety standard for this position — a regular ceramic or electrolytic cannot legally substitute. A failed X2 capacitor causes EMI compliance failure, mains buzzing, and in extreme cases a controlled fail-safe open that takes the input filter offline.

How the X2 Capacitor Fails

X2 film capacitors are designed to fail safe — they degrade open rather than short, which is why they're allowed across the AC line. After years of mains-transient stress, surges, and humidity exposure, the metallised film inside slowly self-heals away from defects, gradually losing capacitance. Symptoms: increased EMI on conducted-emissions tests, audible buzz at mains frequency in the PSU, and on the bench a measured capacitance well below the 2.2µF rating. Mining PSUs run hot inside crowded enclosures, so this drift happens faster than in consumer gear.

Replacement Procedure

Disconnect the PSU from mains and bleed the bulk capacitors (5 minutes minimum, or use a bleed resistor). Identify the failed MKP62 — usually a yellow or red rectangular box mounted directly across the AC input traces, near the input fuse and the common-mode choke. Desolder the old part, clean the through-hole pads, and fit the new MKP62 305V X2 2.2µF in the same orientation. Critical: only fit a part with X2 marking — never substitute a non-safety capacitor in this position. Visually verify the markings match before powering on.

MKP62 305V X2 Specifications

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Stocking MKP62 X2 capacitors for a PSU repair line? Contact us at contact@lys-sz.com for volume pricing. Worldwide shipping from our Shenzhen warehouse.