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(iv) Trip mode
TRIP commands for opening the CB poles
The DIFL function issues a per-phase trip signal so that a per-phase TRIP COMMAND will be
generated in the TRC function; set a single-phase trip (1P) mode for scheme switch [DIFL-
TPMD]. The user can also set a three-phase trip (3P) mode if TRIP_COMMANDs are not
required to generated in an individual phase. Note that the TRIP_COMMANDs will be issued
for the CB in the TRC function after collecting signals from the other functions. In the ‘1P
mode’ operation, set Per-PHASE for the switch [TP-MODE]. Remember that TRIP
_COMMANDs will be issued in three-phases unconditionally if 3-PHASE is set for the [TP-
MODE]. The user should recognize that the settings of the [DIFL-TPMD] (see Figure 2.2-3) and
the setting [TP-MODE] (see Figure 2.33-3) have cooperation to trip the CB correctly.
Note: Setting 1-PHASE is used to issue TRIP_COMMANDs in three-phases if phase-to-
phase faults occur. For your information, the settings in TRC function affect the
other trip signals from the ZG and other functions. See
Chapter Relay application:
Trip circuit
for more information.
TRIP commands during CTF
The trip signal can be influenced by the operation in CT circuit-failure detection function (CTF-
DIFL†). The user can select a block signal in response to the CT circuit-failure using scheme
switch [DIFL-CTFBlk]. If blocking a trip signal upon occurrence of the CT circuit-failure is not
required, the user should set Non for scheme switch [DIFL-CTFBlk]. If the failed phase is only
required to blocked on occurrence of the CT circuit-failure, the user should set Block-PerP for
the scheme switch [DIFL-CTFBlk]. On the other hand, if required is to block a trip signal to all
three phases upon occurrence of the CT circuit-failure, the user has to set Block-3P for the
scheme switch [DIFL-CTFBlk].
†Note: The operation and the logic of the CTF-DIFL function is discussed in section
2.2.3.
(v) Switch for DIFL operation
The user should set On for scheme switch [DIFL-EN] prior to the DIFL operation, as illustrated
in Figure 2.2-3. The DIFL#1 element and the DIFL#2 element can be operated per phase basis;
thus the DIFL function can issue respective trip signals “DIFL-TRIP-A, -B, and -C”. Note both
DIFL elements run in parallel; the DILF elements are not designed to operate in hot-standby
mode.
(vi) Setting for autoreclose function
Autoreclose (ARC) function is to re-close the CB again to restore service after tripping the CB.
If the user wishes to operate the ARC function, the user should set Non for scheme switch
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