The relay type NA016 is typically used in radial HV, MV and LV networks as feeder or power transformer protection.
In solidly grounded systems the residual overcurrent protection can be used on feeders of any lenght, while in ungrounded or Petersen coil and/or resistance grounded systems, the residual overcurrent protection can be used on feeders of small lenght in order to avoid unwanted trippings due to the capacitive current contribution of the feeder on external ground fault.
