Toshiba GR200 Series - (i) Blocking EF by ICD; (ii) Blocking EF by VTF; (iii) Blocking EF by CTF; (iv) EF operation for autoreclose

6F2S1914 (0.49)
GRL200 (Soft 033 & 037)
- 252 -
(i) Blocking EF by ICD
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 Relay
application: Inrush current detection function .
(ii) Blocking EF by VTF
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.
(iii) Blocking EF by CTF
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.
(iv) EF operation for autoreclose
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.
(v) Signal of EF trip
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.
2.16.6 Scheme logic
The scheme logic for both the non-directional and the directional EF1 element is illustrated in
Figure 2.16-6; Figure 2.16-7 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 Relay application: Trip circuit
function )