821799-SF is a very high-performance single-phase EMC/EMI filter from the FN2520 series, designed for applications requiring excellent electromagnetic compatibility in compact form factors. The filter operates at rated voltages up to 277 VAC / 400 VDC with a two-stage design that delivers superior attenuation across differential and common modes, with rated currents ranging from 10 A to 32 A at 50°C operating temperature. Key technical characteristics include low leakage current of 0.82 mA at 277 VAC/50 Hz, inductance values ranging from 0.9 mH to 8.3 mH depending on current rating, and capacitance components (Cx1: 1 µF, Cx2: 0.47 µF, Cy1/Cy2: 4.7 nF) optimized for EMI suppression. The filter fits within a single height unit (1 HU) of a 19" rack application, making it ideal for robotics, datacenters, and other space-constrained environments where high-performance EMC filtering is essential.