Negative Sequence Voltage Threshold
This is the percentage of system voltage above which a Trip event will occur.
(Range: 1-100; Step: 1; Default: 15) This setting always uses
Phase-to-Ground
mode
even when the
Voltage Reporting
setpoint on the
Setup>General>Site Related>System
screen is set to
Phase-to-Phase
mode. For example, when the
System Phase-to-Phase
Voltage
setpoint on the
Setup>General>Site Related>System
screen is set to 12.47 kV
(7.2 kV phase-to-ground), the
Negative Sequence Voltage Threshold
setpoint is set to
15%, and the Negative Sequence X-Side and Y-Side Voltage (V2) is 1,100 volts, the
Negative
Sequence Voltage Threshold
setting has been exceeded (1,100/7,200 = 15.3%).
Negative Sequence Current Restraint Threshold
This is the current (in primary amperes) above which a Trip event is prevented.
(Range: 10-16,000; Step: 1; Default: 50) The stated maximum is for 15-kV IntelliRupter
fault interrupters; 27-kV and 38-kV models are limited to 12,500 amps maximum.
Note:
The current restraint is effectively disabled when set to 16000. This would be
the recommended setting for DER applications where the intent is to open as fast as
possible on voltage loss.
Unbalance Time to Trip
This is the time (in seconds) the
Voltage Unbalance
element must be above its threshold
for a trip event to occur. (Range: 0.00-600.00; Step: 0.01; Default: 30.00)
Unbalance Reset Time
This is the time (in seconds) reset voltage must be present for the
Unbalance Voltage
element to reset. (Range: 0.00-600.00; Step: 0.01; Default: 1.00)
Source Voltage Indication
Source voltage is always indicated.
Good Source Voltage Indication
This is the percentage of system voltage above which the source is considered good.
(Range: 0-100; Step: 1; Default: 90)
Good Source Time to Detect
This is the time (in seconds) good source voltage must be present for source to be reported
good. (Range: 0.00-600.00; Step: 0.01; Default: 1.00)
Low Source Voltage Threshold
This is the percentage of system voltage below which the source is considered low.
(Range: 0-99; Step: 1; Default: 73)
Time to Detect Low Voltage
This is the time (in seconds) low source voltage must be present for the source to be
reported low. (Range: 0.00-600.00; Step: 0.01; Default: 0.10)
80 S&C Instruction Sheet 766-530
Protection Setup