Default setting: 30%
0 Uerd message delay:
Transient earth fault
An earth fault identified when the absolute value the zero sequence voltage Une is
higher than the threshold value set for Uerd.3.
– The delayed earth fault message.2.
Regulation always stops when earth fault occurs because the same zero sequence volt-
age would measured across the coil's whole adjustment range making regulation
impossible.
11. also not certain whether older coils can moved when earth fault oc-
curs because the drive unit not always equipped overcome the high magnetic forces.1 Earth fault
0 Uerd threshold
If the set threshold exceeded, the coil movements and the current injection (if used) are
suppressed.Page 105
Detailed description REG-DP/ REG-DPA parameters
Four parameters determine the regulator's behaviour when earth fault occurs. The earth fault must also occur
during the whole delay time.
The earth fault generates two types messages:
– The immediate earth fault message
This message displayed soon the earth fault has been identified.
Une
Transient earth fault
Message delay
T_V
T_EW
t
T_EW Transient earth fault time
T_V Uerd message delay
Figure 76: Time behaviour the earth fault
. The below figure displays the time behaviour
for the regulator.
This message displayed after the set delay time. This value relates the nominal value the coil's nominal voltage
