Anti-resonance harmonic filters are designed to prevent resonance conditions and reduce harmonic distortion and power losses in the PFC system. Capacitors are connected in series to the reactor. These "detuned" PFC systems are scaled in such a way that the self-resonant frequency is below that of the lowest harmonic. Standard versions of EPCOS reactors from are available for rated voltages of 400 V and 440 V and with outputs of 10 kvar to 100 kvar at 50 or 60 Hz. Other voltages are available upon request. They offer de-tuning factors of 5.67, 7 or 14 %.