EMI filter

The Schaffner FN 2200 DC EMC/EMI filter series for photovoltaic panels is designed to prevent conducted RF from the inverter, reducing the potential for radiated emission with the PV panels and the wiring acting as antennas.

Solar energy inverters generally have high frequency levels in the range 10 to 100 kHz and the DC and AC wiring can act as antennas for radiation. Additional noise is generated due to reverse recovery of diodes and other switching effects. This can generate more power at high frequencies than the commutation process.

The filters are installed between the PV panel and inverter operational blocks. They are suitable for DC voltages to 1200 and are available in ratings varying from 25 to 1500 A and conform to IEC/EN 60939 as well as UL 1283 and CSA 22.2 (No 8, 1986).

To prevent erroneous installation, the PV side and inverter side of the filters are identified by the asymmetrical filter housing.

The filters meet EMC requirements of EN61000-6-5/4 and are designed to filter out differential as well as common mode noise.

Ringing at high frequencies due to switching transients exciting parasitic resonances in the power circuits is a significant source of differential (symmetrical) noise.