With increasing use of electronic equipment fed from low voltage distribution systems, problems have arisen in recent years from the harmonic currents dissipated by such equipment. One of the problems is that capacitors directly connected to the mains voltage, such as those in static var compensators, can be overloaded on account of their lower reactance to higher frequencies. The common means of avoiding this is to use de-tuning, i. e. connecting each capacitor in series with a small inductance. While this actually does solve the problem, the dimensioning of this inductance bears both the risk of causing new problems and the chance of mitigating the level of harmonics in the LV system. This presentation wants to give guidance how to dimension a static var compensator in a way to avoid the problems and at the same time use the device as a harmonics filter.