Advertisement
harmonic associated with magnetizing inrush is present. Non is set for the scheme switch
[SEF1-2fBlk] as the default setting. For more information about the ICD function, see Chapter
2.10.
Blocking SEF by VTF
(ii)
The operation of the SEF element can be blocked by the voltage transformer failure (VTF)
function via a scheme switch. For example, Block is set for the scheme switch [SEF1-VTFBlk]
to block the operation of the SEF1 element during a VTF condition. Non is set for the scheme
switch [SEF1-VTFBlk] as a default. For more information about the VTF, see Chapter 2.20.
SEF operation for autoreclose
(iii)
The SEF element activates the auto-reclose (ARC) function. However, if ARC is not required,
Block is set for the scheme switch [SEF1-ARCBlk]. Block is set for the scheme switch [SEF1-
ARCBlk] as a default.
Signal of SEF trip
(iv)
When a user requires an alarm signal in place of the trip signal; for example, set Alarm for the
scheme switch [SEF1-UseFor]. Trip is set for the scheme switch [SEF1-UseFor] for the normal
trip operation.
Setting for Petersen coil earthed system
2.4.6
If the protection is required in Petersen coil (resonant) earthed system, SEF element can
operate together with a residual power element (RP). Figure 2.4-6 exemplifies the SEF1
element will be restrained with the RP1 element when On is set for setting [RP1-EN] during
the setting [SEF1-DIR]=Forward. Accordingly, SEF1-OPT trip signal will not be issued unless
a fault is determined stably with an entering current (i.e., residual current; Ie at VCT terminal)
and polarizing voltage (i.e., reference voltage; Ve at VCT terminal).
- 79 -
6F2T0207 (0.01)
GRE200 (5,6)
Advertisement
