Toshiba GR 200 Series, Instruction Manual

Page: 184 / 1563

6F2S1915 (0.46)
GRZ200 (Soft 031 & 032)
- 163 -
(viii)
Summary of OC operation
Table 2.5-5 shows the summary of OC operation. Note that
DEF
will be set unconditionally in
IEC-NI, VI, EI and UK-LTI characteristics (†).
Table 2.5-5 Type and standard board in the OC1 (A tick shows a selectable function)
Characteristics
DT
IDMT
IEC-NI IEC-VI IEC-EI UK-LTI IEEE-MI IEEE-VI IEEE-EI US-CO2 US-CO8 Original
Scheme
sw
itch
[O
C
1
-T
imer
]
DT

IEC-NI
✓
IEC-VI
✓
IEC-EI
✓
UK LTI
✓
IEEE-MI
✓
IEEE-VI
✓
IEEE-EI
✓
US-CO2
✓
US-CO8
✓
Original
✓
Scheme
sw
itch
[O
C
1
-Rt
imer
]
DEF
N.A
✓
†
✓
†
✓
†
✓
†
✓ ✓ ✓ ✓ ✓ ✓
DEP
N.A
✓
N.A
✓
N.A
✓
N.A
✓
N.A
✓
N.A
✓
2.5.3
Threshold value for operation
The value of threshold current at which the OC element will pick-up is configured by a setting;
the setting [
OC1
] is provided for both the IDMT and DT characteristics. Note that the settings
of the threshold levels have distinct values in the respective OC elements. A rating current for
the input is defined either 1A or 5A; the input rating is defined on a VCT. (For more information
about the VCT, see Chapter
Technical description: Transformer module for AC analogue input
).
(2.34.3a)
2.5.4
Reset Ratio
The ratio of the threshold current for pick-up to reset is applied using a setting; for example,
the ratio for the OC1 element is set using the setting [
OC1-DPR
]. The reset ratios for the other
OC elements are also provided.
2.5.5
Miscellaneous functions
(i)
Trip mode
Every OC element has a selectable tripping mode; the mode is selected using a scheme switch.
For the OC1 element, for example, a scheme switch [
OC1-OPMD
] is provided. When a trip is
required for any faults that are detected,
3POR
(a fault occurs in one or more phases) is set for