Adding this capacitor (or two) in parallel to the input of any EMI filter will improve suppression of the differential noise and power waveform disturbances. Its positive impact will also propagate down the power line, hence other equipment will benefit from a cleaner power.
Use with caution after transformers. Adding a substantial capacitance to the secondary may result in elevated voltage. In case a high-energy storage is deployed at the transformer’s secondary a thorough checking of the resulting voltage is highly recommended.
Note 1: A filtered IEC inlet and the Elite 2A EMI filter are displayed for the illustration purposes only.
Note 2: For allowing the positive filtering impact of the capacitor to propagate down the power line the use of an unfiltered power inlet is recommended.