Hitachi Relion 670 Series Applications Manual page 106

Section 7
Impedance protection
If magnitudes of both phase currents (I
I0MinPhSel, it indicates that a phase-to-phase fault has occurred in the system. At this condition, the
measuring loops are enabled based on the setting mode ModeI0StRel and the respective loops will
be released for distance measuring.
Phase preference
For faults on phase L2, after distance and direction decision is fulfilled, an alarm will appear and the
additional timers t1L2 to t6L2 will start. If the starting element is reset before the expiry of (and
therefore before trip) the zone timers tPEZx plus basic time tGL2, the UL1E will be checked against a
set limit UL1E < U0Min at the end of 100ms after the reset of starting element.
The basic time tGL2 is effective only during the underimpedance or residual overcurrent start. If the
voltage UL1E is greater than the set limit U0Min, the start signal is maintained. A trip will occur if the
voltage UL1E does not fall below the set limit by the end of extra time t1L2 to t6L2 that are assigned
to the respective zones.
ModePhPref: In compensated earthed systems, phase L2 will be specially treated. Two operation
modes i.e. Equal priority and L1 before L2 of phase preference variants are implemented. The
default is set to Equal priority.
OpModet0L2: For Off/On operation of the t0L2 timer if phase preference is set.
t0L2: An additional time delay to the trip phase L2 in stub line.
OpModet1L2: For Off/On operation of the t1L2 timer if phase preference is selected. The default
setting is On.
t1L2: An additional time delay to trip phase L2 if the phase preference is set to trip phase L2 in zone
1. The default setting is 1.5 s.
OpModet2L2: For Off/On operation of the t2L2 timer if phase preference is selected. The default
setting is Off.
t2L2: An additional time delay to trip phase L2 if the phase preference is set to trip phase L2 in zone
2. The default setting is 2.5 s.
OpModet3L2: For Off/On operation of the t3L2 timer if phase preference is selected. The default
setting is Off.
t3L2: An additional time delay to trip phase L2 if the phase preference is set to trip phase L2 in zone
3. The default setting is 0.0 s.
OpModet4L2: For Off/On operation of the t4L2 timer if phase preference is selected. The default
setting is Off.
t4L2: An additional time delay to trip phase L2 if the phase preference is set to trip phase L2 in zone
4. The default setting is 0.0 s.
OpModet5L2: For Off/On operation of the t5L2 timer if phase preference is selected. The default
setting is Off.
t5L2: An additional time delay to trip phase L2 if the phase preference is set to trip phase L2 in zone
5. The default setting is 0.0 s.
OpModet6L2: For Off/On operation of the t6L2 timer if phase preference is selected. The default
setting is Off.
100
L1
The time steps from t0L2 to t6L2 listed below can be selected by settings OpModet0L2 to
OpModet6L2 for stub line and each distance zone 1 to zone 6 respectively.
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and I ) are almost equal or less than the set value
L2
1MRK506375-UEN Rev. N
GUID-9C79F56B-B4CB-4214-90D2-019DE1351F54 v4
Railway application RER670
Application manual