Basler BE1-CDS220, Инструкция по эксплуатации

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4-26 Protection and Control BE1-CDS220
Enable the Time Overcurrent function by selecting its mode of operation from the Mode pull-down menu.
To connect the functions inputs, select the button for the corresponding input in the BESTlogic Function
Element screen. The BESTlogic Expression Builder screen will open. Select the expression type to be
used. Then, select the BESTlogic variable, or series of variables to be connected to the input. Select
Save when finished to return to the BESTlogic Function Element screen. For more details on the
BESTlogic Expression Builder, see Section 7, BESTlogic Programmable Logic. Select Done when the
settings have been completely edited.
The BESTlogic settings for Time Overcurrent are provided in Table 4-12. These settings enable an
element by attaching it to the CT input circuits and provide blocking control as determined by the logic
expression assigned to the block input.
Table 4-12. BESTlogic Settings for Time Overcurrent
Function Range/Purpose Default
Mode
0
1
2
G
= Disabled
= CT Input Circuit 1
= CT input Circuit 2
= Independent Ground Input (#51N functions only)
0
BLK Logic expression that disables function when TRUE. 0
Example 1. Make the following settings to the 51P element using BESTCOMS. See Figure 4-22.
Mode: CT Input 1
BLK: 0
Operating Settings for Time Overcurrent
Operating settings are made using BESTCOMS. Figure 4-23 illustrates the BESTCOMS screen used to
select operational settings for the Time Overcurrent element. To open the screen, select Overcurrent from
the Screens pull-down menu and select either the 51, 151, or 251 tab. Alternately, settings may be made
using S<g>-51 ASCII command or from the optional HMI Screens 5.#.4.1 through 5.#.4.3,
\PROT\SG#\51\, \PROT\SG#\151\, or \PROT\SG#\251.
See Negative-Sequence Overcurrent Protection later in this section for information on setting the
negative-sequence overcurrent protection.
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.
Beside the Logic pull-down menu is a pull-down menu labeled Settings. The Settings menu is used to
select the setting group that the element's settings apply to.
Table 4-13 summarizes the operating settings for Time Overcurrent.
NOTE
If the unit has five ampere phase inputs and a one ampere independent ground
input, the valid pickup setting range of the neutral overcurrent functions will be
dependent upon the logic mode setting which designates whether the three-
phase residual or the independent ground input is to be monitored. If changing
logic schemes or settings causes a neutral overcurrent setting to be OUT OF
RANGE, the out of range setting will be forced in-range by multiplying or dividing
the current setting by five.