The earth current, by circulating through RN and RE energizes the
PEN conductor and, therefore, the user’s ECPs. The contact resistance
with earth also limits this ground current and in some cases can be
very high (e.g., line in contact with snow or sand). The distributor’s
overcurrent devices, therefore, may not be able to clear the fault within
the maximum permissible times of Table 7.1, exposing persons to the
risk of electric shock.