9328900990 Rev L BE1-951 Protection and Control 4-15
Figure 4-13. Overcurrent Protection Screen, 50T Tab
The default unit of measure for the Pickup setting is secondary amps. Primary amps (Pri Amps), per unit
amps (Per U Amps), and percent amps (% Amps) can also be selected as the pickup setting unit of
measure. The unit of measure for the Time setting that represents the element's time delay defaults to
milliseconds. It is also selectable for seconds, minutes, and cycles.
If time delay settings are made in cycles, they are converted to seconds or milliseconds (per the nominal
frequency setting stored in EEPROM) before being stored and rounded to the nearest whole millisecond.
See Section 3, Input and Output Functions, Power System Inputs, Current Measurement, for more
information about this setting. If the nominal frequency setting is being changed from the default (60
hertz) and time delay settings are being set in cycles, the frequency setting should be entered and saved
before making any time delay settings changes.
At the top center of the screen is a pull-down menu labeled Logic. This menu allows viewing of the
BESTlogic settings for each preprogrammed logic scheme. A custom logic scheme must
be created and
selected in the Logic pull-down menu at the top of the screen before BESTlogic settings can be changed.
See Section 7, BESTlogic Programmable Logic. To the right of the Logic pull-down menu is a pull-down
menu labeled Settings. The Settings menu is used to select the setting group that the elements settings
apply to.
Table 4-5 summarizes the operating settings for instantaneous overcurrent.
Table 4-5. Operating Settings for Instantaneous Overcurrent
Range
Setting
1 A 5 A
Increment Unit of Measure Default
Pickup
0 = Disabled
0.1 to 30
0 = Disabled
0.5 to 150
0.01 for 0.1 to 9.99
0.1 for 10.0 to 99.9
1.0 for 100 to 150
Secondary Amps 0
0 to 999 milliseconds 1 Milliseconds
0.1 for 0.1 to 9.9 Seconds
0.1 to 60 seconds
1.0 for 10 to 60 Seconds
0 to 3600 cycles (60 Hz)
Time
0 to 2500 cycles (50 Hz)
∗
Cycles
0
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