Toshiba GR-200 Series Instruction Manual page 69

Miscellaneous functions
2.2.5
Blocking EF by ICD
(i)
The operation of each EF element can be blocked if the ICD function detects a second harmonic
current caused by the magnetizing inrush current phenomenon when a transformer is
energized. For example, for the EF1 element, the scheme switch [EF1-2fBlk] is provided, and
Block should be set when the user wishes to block the EF1 element when the second harmonic
associated with magnetizing inrush is present. Non is set for the scheme switch [EF1-2fBlk] as
the default setting. For more information about the ICD function, see Chapter 2.10.
Blocking EF by VTF
(ii)
The operation of the EF element can be blocked by the voltage transformer failure (VTF)
function via a scheme switch. For example, Block is set for the scheme switch [EF1-VTFBlk] to
block the operation of the EF1 element during a VTF condition. Non is set for the scheme
switch [EF1-VTFBlk] as a default.
Blocking EF by CTF
(iii)
The operation of the EF element can be blocked by the current transformer failure (CTF)
function via a scheme switch. For example, Block is set for the scheme switch [EF1-CTFBlk] to
block the operation of the EF1 element during a CTF condition. Non is set for the scheme
switch [EF1-CTFBlk] as a default.
EF operation for autoreclose
(iv)
The EF element activates the auto-reclose (ARC) function. However, if ARC is not required,
Block is set for the scheme switch [EF1-ARCBlk]. Block is set for the scheme switch [EF1-
ARCBlk] as a default.
Signal of EF trip
(v)
When a user requires an alarm signal in place of the trip signal; for example, set Alarm for the
scheme switch [EF1-UseFor]. Trip is set for the scheme switch [EF1-UseFor] for the normal
trip operation.
Scheme logic
2.2.6
The scheme logic for both the non-directional and the directional EF1 element is illustrated in
Figure 2.2-6; Figure 2.2-7 shows grouping commands for the trip circuit (TRC). The EF1 signal
is generated when the pickup current exceeds a threshold, and then trip signals are injected
into the TRC. (For more information, see Chapter 2.23)
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6F2T0200 (0.15)
GRE200 (1,2)