Portugal has been one of the European countries where Distributed Generation (DG) has taken a high level of importance for the overall system. In 2015 about 50 % of the Portuguese electrical energy consumption was produced at the distribution network. This high level of DG has given rise to new challenges for the DSO, one of the latest concerns the protection requirements for DG and the network arising from the ever increasing self-consumption DG. Two major issues are placed upon the DSO: the need to keep DG projects economically feasible without compromising the network safety; and the new exporting mode of MV/LV secondary substations. One of the issues being raised by the low-power clients wanting to install a self-consumption generation plant is the need for a maximum zero sequence voltage protection (V0>) that requires the installation of a VT in most cases. The paper performs a new analysis of the network quantities on the LV side (near DG) under a ground fault on the MV feeder. Simulations of multiple scenarios show that the voltage on the LV side can change by a ground fault on the MV side. The analysis confirm that the V0> protection is the strongest robust way to protect the network against a ground fault on the MV side.