FN2090B-20-08

Overview

The Schaffner FN2090B-20-08 is a single-phase, two-stage EMI power line filter rated for 20 A at 250 VAC. Designed for chassis mounting with screw terminals, it features B-type construction without Y-capacitors to ensure low leakage current, making it suitable for medical applications. The unit operates within a frequency range of DC to 400 Hz and withstands temperatures from -25°C to +100°C. Key electrical parameters include a capacitance value of 470 nF, an inductance of 14 mH, and a leakage current of 0.5 mA. It includes a 330 kΩ discharge resistor and measures 113.5 mm in length.

Feature Summary

• Two-stage filtering architecture providing high differential and common-mode attenuation using high-permeability core chokes.
• B-type configuration eliminates Y-capacitors to achieve ultra-low leakage current for medical safety compliance.
• Chassis-mount design facilitates rapid installation and secure mechanical fixation in equipment enclosures.
• Integrated discharge resistor ensures safe voltage dissipation when the power supply is disconnected.

Applications

• Medical diagnostic and therapeutic equipment requiring strict leakage current limits
• Industrial control systems operating in electrically noisy environments
• Power supplies and inverters demanding high conducted emission attenuation

Procurement Notes

Verify that the specific order matches the B-type designation, which indicates the absence of Y-capacitors essential for medical isolation requirements. Confirm terminal type compatibility, as this model utilizes screw connections rather than fast-on tabs. Ensure the application environment remains within the specified temperature range of -25°C to +100°C to maintain performance integrity and safety certification validity.

Selection Notes

Select this component when low leakage current is critical, such as in patient-connected medical devices, where standard filters with Y-capacitors would exceed safety limits. The two-stage design offers superior attenuation compared to single-stage alternatives like the FN2030 series within the same form factor. Consider the screw terminal requirement for wiring infrastructure, as it differs from the fast-on options available in other FN2090 variants.

Part Context

This component belongs to the FN2090 series, which provides multi-stage EMI filtering for currents ranging from 1 to 30 A. The series is characterized by high inductivity relative to amperage, delivering enhanced noise suppression without increasing physical dimensions significantly compared to older generations. The B-type suffix specifically denotes the medical-safe variant optimized for minimal capacitive coupling to ground.

Replacement Considerations

The part number alias 802998-SF refers to the identical FN2090B-20-08 unit under TE Connectivity branding. Direct substitution requires matching the 20 A rating, 250 VAC voltage, and B-type low-leakage specification. Verify that any alternative maintains the screw terminal interface and two-stage topology to preserve circuit attenuation characteristics.