Over Frequency Threshold
This is the frequency (in hertz) above which a
Trip
operation will occur. Enter between
50 and 62 Hz, but the setting will be valid only if it falls within the range (System Frequency,
System Fre 2). (Minimum: System Frequency; Maximum: System Frequency
+ 2 Hz; Default: System Fre 0.5 Hz; Increment: 0.01)
Frequency Time to Trip
This is the time (in seconds) the
Under Frequency
or
Over Frequency Threshold
setting must be exceeded for a
Trip
operation to occur. (Range: 0.06-600.00; Step: 0.02;
Default: 30.00)
Reset Time
This is the time (in seconds) frequency must be present for the
Frequency
element to
reset. (Range: 0.06-600.00; Step: 0.02; Default: 1.00)
Good Frequency Indication
(Loop Restoration Only)
When the
Good-Frequency Indication
mode is enabled, a
Loop Restoration
Close
command will be blocked if the frequency is below the
Under Frequency
Threshold
setting for the
Under Frequency Minimum Time to Detect
setting. The
Under Frequency Threshold
setting is (Default: System Frequency – 0.5 Hz.
49.50 Hz when
Setup>General Site-Related>System Frequency
= 50 Hz, or 59.50 Hz when
Setup>General Site-Related>System Frequency
= 60 Hz; Minimum: System Frequency
– 1 Hz; Maximum: System Frequency; Increment: 0.01 Hz) The
Under Frequency Min
Time to Detect
setting is (Default: 0.10 s; Maximum: 10.0 s; Increment 0.001)
Under Frequency Enabled
Specify the
Yes
or
No
(default) setting.
Under Frequency Threshold
This is the frequency (in hertz) below which a
Trip
operation will occur. Enter between
47 and 60 Hz, but the setting will be valid only if it falls within the range (System
Frequency - 1, System Frequency). (Minimum: System Frequency - 1 Hz; Maximum:
System Frequency; Default: System Frequency - 0.5 Hz; Increment: 0.01)
Under Minimum Time to Detect
This is the time (in seconds) the
Under Frequency Threshold
setting must be exceeded
for a
Trip
operation to occur. (Range: 0.00-10.00; Step: 0.01; Default: 0.01)
108 S&C Instruction Sheet 766-530
Protection Setup