4-14
Protection and Control
BE1-951
Operating Settings for Instantaneous Overcurrent Elements
Operating settings for the 50T functions consist of pickup and time delay values. The pickup value
determines the level of current required for the element to start timing toward a trip. Time delays can be set
in milliseconds, seconds, or cycles. The default is milliseconds if no unit of measure is specified. Minimum
timing resolution is to the nearest one-half cycle. A time delay setting of zero makes the element
instantaneous with no intentional time delay. Operating settings are made through the ASCII command
interface using the S<g>-50T command. Settings can also be changed or viewed at the front panel HMI
using screens 5.x.5.1 through 5.x.5.6, where x equals 1 for setting group 0, 2 for setting group 1, 3 for setting
group 2, or 4 for setting group 3. Instantaneous overcurrent operating settings are summarized in Table 4-6.
Table 4-6. Instantaneous Overcurrent Operating Settings
Setting
Range
Increment
Unit of
Measure
Default
1 A
5 A
Pickup
0 = disabled
0.1 to 30
0 = disabled
0.5 to 150
0.01 for 0.01 to 9.99
0.1 for 10.0 to 99.9
1.0 for 100 to 150
secondary
amperes
0
Time Delay
0 to 999 milliseconds
1
milliseconds
0
0.1 to 60 seconds
0.1 for 0.1 to 9.9
seconds
1.0 for 10 to 60
seconds
0 to 3600 cycles (60 Hz)
9
cycles
0 to 2500 cycles (50 Hz)
Direction
N = Nondirectional
F = Forward directional
R = Reverse Directional
N/A
N/A
N
9
Time delays less than 10 cycles can be entered to the nearest 0.1 cycle from the front panel
HMI. All time delays can be entered to the nearest 0.01 cycle from the ASCII command
interface. Time delays entered in cycles are converted to milliseconds or seconds. Increment
precision after conversion is limited to that appropriate for each of those units of measure.
S<g>-50T Command
Purpose:
Read/Set 50TP pickup level and time delay
Syntax : S<g>-<x>50T<p>[=<Pickup>,<Time
Delay>,<Direction>]
Comments:
g = setting group 0, 1, 2, or 3. Use # as a wildcard to read or change all groups.
x = 1 for 150 or no entry for 50
p = P for Phase, N for Neutral, or Q for Negative Sequence. See Table 4-6 for S<g>-
50T settings information
S<g>-50TP Command Examples
1.
Set the group 0 50T phase setting at 25 amperes, 0 delay time, and nondirectional.
>S0-50TP=25,0,N
2.
Set the 50TN pickup for all setting groups at 2 amperes, set the time delay at 10 seconds, and set
the element for forward directional.
>S#-50TN=2,10s,F
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. See Section 3,
Input and Output Functions,
Current Measurement Functions 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.
