This paper presents a study of overvoltages caused by cloud-to-ground lightning strikes on loads connected
to a complex low-voltage distribution network. The importance of the transformer grounding in
the resulting load overvoltages is discussed for two different lightning events. These events emphasize
either the induced-voltage component or the surge transference through the distribution transformer as
the main source of overvoltages on the connected loads. A brief discussion is also presented on the effi-
ciency oflow-voltage surge arresters in protecting loads connected to complex low-voltage networks. The
obtained results indicate that the effectiveness of improving the transformer grounding and of installing
surge arresters at specific points of the low-voltage network is limited in terms of load protection if
a complex network topology is considered. In some cases, especially for a lightning strike close to the
low-voltage line, improving the transformer grounding can even increase load overvoltages