Importance of harmonic interactions between installations containing power-electronic based sources and loads has grown in recent years. Such interactions of voltage and current harmonics within a typical low-voltage network and an islanded microgrid with different LEDs are analyzed in this paper. The analysis is based on measurements of two laboratory setups representing a LV network and microgrid with an island-capable power electronic source. The interactions between voltage and current harmonics, which are mainly dependent on the frequency dependent network impedance, are analyzed. The differences between the harmonic interactions in typical networks and in power-electronic based networks are discussed.