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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
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
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 wou ld 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
character is always S. (These relays are always supplied in a
draw-out case for semi-flush mounting .)
1.12 Time Overcurrent Characteristic
Curves
1
Table
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.
J,
the internal power for the
If any one oft he three features
.
1.
The last
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
Cha racteristic
b1
Short Inverse Time
b2
Long Inverse Time
b3
Definite Time
Moderately Inverse Time
b4
...
Inverse Time
b5
b6
Very Inverse Time
b7
Extremely Inverse Time
....
12T
b8
12T
c1
with limit 1
12T
c2
with limit 2
12T
c3
with limit 3
I2T
c4
with limit 4
12T
c5
with limit 5
12T
c6
with limit 6
12T
c7
with limit 7
12T
with limit 8
cs
Page 5
Figure
A.1
A.2
A.3
A.4
A. 5
A.6
A.7
A.S
A.9
A.10
A.11
A.12
A.13
A.14
A.15
A.16
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