Toshiba GR-200-5 Instruction Manual page 119

Blocking OCN by CTF
(iii)
The operation of the OCN element can be blocked by the current transformer failure (CTF)
function via a scheme switch. For example, Block should be set for the scheme switch [OCN1-
CTFBlk] to block the operation of the OCN1 element during a CTF condition. Non is set for the
scheme switch [OCN1-CTFBlk] as a default. For more information about the CTF, see Chapter
2.21.
OCN operation for autoreclose
(iv)
The OCN element activates the auto-reclose (ARC) function. However, if ARC is not required,
Block is set for the scheme switch [OCN1-ARCBlk]. Block is set for the scheme switch [OCN1-
ARCBlk] as a default.
Signal of OCN trip
(v)
When a user requires an alarm signal in place of the trip signal; for example, set Alarm for the
scheme switch [OCN1-UseFor]. Trip is set for the scheme switch [OCN1-UseFor] for the normal
trip operation.
Scheme logic
2.5.6
The scheme logic of both the non-directional and the directional OCN1 is illustrated in Figure
2.5-6; Figure 2.5-7 shows grouping commands for the trip circuit (TRC). The OCN1 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)
For DT characteristic
OCN1
For IDMT characteristic
OCN1 PU
From ICD
ICD-OR
OCN1-2PBlk
Block
OCN1-EN
ON
From VTF
VTF_DETECT
OCN1-VTFBLK
From CTF
CTF_DETECT
OCN1-CTFBLK
8000011BB0
800001EBB0 OCN1_BLOCK
8000011BB1
800001EBB1 OCN1_INST_OP
†Note: The presence of 'OCN1' and 'OCN1PU' signals depends on the operation
&
&
&
&
BLOCK
≥1
&
BLOCK
Figure 2.5-6 Scheme logic of OCN1
TOCN1
& t
&
0.00-300.00s
&
&
≥1
&
DT
OCN1_Timer
OCN1-USEFOR
IEC-NI
IEC-VI
OCN1-ARCBLK
IEC-EI
UK-LTI
IEEE-MI
IEEE-VI
IEEE-EI
US-C02
US-C08
ORIGINAL
- 99 -
6F2T0207 (0.01)
8000011C23
OCN1†
8000011C27
OCN1PU†
8000011B60
0
≥1
OCN1-OPT
&
OCN1-OPT-TRIP
TRIP
&
OCN1-OPT-ALARM
ALARM
&
BLOCK OCN1-ARC-BLOCK
GRE200 (5,6)
To Grouping logic