This paper presents a detailed analysis for determining the impact of adding single phase photovoltaic (PV) systems in residential power distribution networks. This study highlights the issues arising due to the increase in fault levels in the network caused by the contribution from PV generators. A typical power distribution network for a suburban area has been modeled in PSCAD and the changes in fault current magnitude with the incremental addition of PV system has been studied. From this analysis it is found that PV generators can contribute fault current of considerable magnitude and thereby has an appreciable impact on the protection system if the PV penetration level is high.