1
General Information
For example, if it is decided that three-phase-with-ground
monitoring is required for an application, then the first character
of the style number is H .
The second character of the style number determines the range
for overcurrent pickup. For example, Sensing Input Tap Range
1 would provide a range of 2.0 to 1 1 .0 A for each phase, and
a range of 0.5 to 5.0 A for ground current. Normally open (NO)
output contacts for tripping the breaker are standard , so output
Option E is the third character. The fourth and fifth characters are
Timing Option Z5, which is standard on the SCOR relay. This
feature allows the timing to be selected from any of the sixteen
overcurrent timing functions illustrated in
Figures A.1
through
A.1 6.
The sixth character represents the voltage of the source
of operating power for the relay. If
J,
the internal power for the
relay is derived from an external source of (a nominal) 1 25 Vdc
or 1 20 Vac.
Since only one target configuration is offered, the seventh
character is B. Note that all of the FUNCTION targets are current
operated. Current operated targets are advantageous because
they confirm that a current flowed in the output circuit as the
result of a trip. (Since the ELEMENT targets are not associated
with any output contacts, they are internally operated.)
If one instantaneous overcurrent element is needed, the eighth
character of the style number is 1
.
If any one oft he three features
provided by Option 1 -2 is desired , the eighth character of the
style number is 2. The ninth character must be C to specify the
communications board option. This would allow communica
tion with a Power Monitor unit or a local terminal.
The tenth character of the style number is 0 if the control power
for the power supply is DC. However, if 1 20 volt AC control
power is to be used, then this character must be
1.
The last
character is always S. (These relays are always supplied in a
draw-out case for semi-flush mounting.)
1.12 Time Overcurrent Characteristic
Curves
Table
1
lists the types ofTime Overcurrent Characteristic Curves
available and the Number entered into the appropriate register
during configuration. The curves are presented in
Figure A.1
through
A.1 6
in
Appendix A.
...
....
Page
5
1 . 1 3 Instantaneous Overcurrent
CharacteristicCurves
The characteristic curves for the instantaneous relay functions
are also presented in
Appendix A. Figure A.1 7
shows the
curve for the Phase Instantaneous function, and
Figure A.18
shows the curve for the Ground Instantaneous function.
Table 1 .
Available Characteristics
Number
Time Overcurrent
Figure
Characteristic
b1
Short Inverse Time
A.1
b2
Long Inverse Time
A.2
b3
Definite Time
A.3
b4
Moderately Inverse Time
A.4
b5
Inverse Time
A.5
b6
Very Inverse Time
A.6
b7
Extremely Inverse Time
A.7
b8
12T
A.S
c1
12T
with limit 1
A.9
c2
12T
with limit 2
A.10
c3
12T
with limit 3
A.11
c4
I2T
with limit 4
A.12
c5
12T
with limit 5
A.13
c6
12T
with limit 6
A.14
c7
12T
with limit 7
A.15
cs
12T
with limit 8
A.16
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