4-16
Protection and Control
BE1-951
Table 4-7. Phase Time-Overcurrent Element BESTlogic Settings
Function
Range/Purpose
Default
mode
0 = Disabled
1 = Enabled
1 = 3-Phase Input Neutral (51N, 151N only)
G = Ground Input (51N, 151N only)
1
BLK logic
Logic expression that disables element when TRUE.
0
BESTlogic settings for the time-overcurrent functions can be made using the SL-51 command.
SL-51 Command
Purpose:
Read or set logic for the phase time-overcurrent element.
Syntax:
SL-<x>51<p>[=<mode>,<BLK logic>]
Comments:
x = 1 for 151, no entry for 51
p = P for Phase, N for Neutral, or Q for Negative Sequence. No entry for p reads or
changes all 51 logic settings. See Table 4-7 for SL-51 settings information.
SL-51 Command Examples
1.
Read the logic for the 51P functions.
>SL-51P
1,0(
These settings indicate that the 51P function is enabled (1) and has no blocking (0).)
2.
Change the 151N logic to select a ground CT and to be blocked when input 1 (IN1) is closed
(TRUE).
>SL-151N=G,IN1
3.
Disable the 51Q function.
>SL-51Q=0
Operating Settings for Time-Overcurrent Elements
The operating parameter settings for the time-overcurrent elements are provided in Table 4-8. Settings can
be entered at front panel HMI screens 5.x.4.1 through 5.x.4.4, where x equals 1 for setting group 0, 2 for
setting group 1, 3 for setting group 2, and 4 for setting group 3. Settings can also be entered by using the
S<g>-51 (setting group number-51/151) command.
Table 4-8. Phase Time-Overcurrent Function Operating Settings
Setting
Range
Increment
Unit of
Measure
Default
1 A
5 A
Pickup
0 = disabled
0.1 to 3.2
0 = disabled
0.5 to 16
0.01 for 0.01 to 9.99
0.1 for 10.0 to 16.0
Secondary Amps
0
Time Dial
0.0 to 9.9
0.0 to 99 (46 only)
0.1
N/A
0
Curve
See Table A-1
N/A
N/A
V2
Direction
N = Nondirectional
F = Forward directional
R = Reverse Directional
N/A
N/A
N
S<g>-51 Command
Purpose:
Read or set the phase time-overcurrent pickup level, time delay, and curve setting.
Syntax:
S<g>-<x>51<p>[=<Pickup>,<Time Dial>,<Curve>, <Direction>]
Comments: g = setting group number 0 or 1. Use # as a wildcard to select all setting groups.
x = 1 for 151 or no entry for 51
p = element type P, N, or Q
