Basler Electric BE1-700 - Manual (Page 86)

The 27X and the 59X elements are enabled or disabled by the Mode input. Four modes are available.
Selecting Mode 0 disables protection. Modes 1, 2, or 3 enable the element as described in this section
under BESTlogic Settings for Auxiliary Undervoltage/Overvoltage. The pickup setting determines the
voltage pickup level of the element. The time delay setting controls how long it takes for the trip output to
become TRUE after the pickup output becomes TRUE. When the monitored voltage increases above the
pickup threshold, the pickup output becomes TRUE and the timer starts. If the voltage remains above the
pickup threshold for the duration of the time delay setting, the trip output becomes TRUE. If the voltage
decreases below the 59X dropout ratio of 98 percent or increases above the 27X dropout ratio of 100%,
the timer is reset to zero.
If the 60FL element trip logic is TRUE and V block is enabled for 3VO blocking (N), the 27X/59X functions
will be blocked if they are set to Mode 2. For more information on the 60FL function, see the paragraphs
later in this section.
The 27X element is equipped with an undervoltage inhibit feature that monitors V
X
input and is selectable
for a Fundamental VX input or a 3VO - 3-phase VT input or a Harmonic V
X
input. When undervoltage
inhibit is selected, undervoltage sensing is disabled anytime the voltage falls below the inhibit threshold.
Undervoltage inhibiting is disabled when the threshold is set to zero. Undervoltage inhibit is used to
prevent undesired undervoltage tripping, such as when a loss of supply occurs.
If the target is enabled for the 59X element, the target reporting function will record a target when the trip
output is TRUE and the fault recording function trip logic expression is TRUE. See Section 6, Reporting
and Alarm Functions, Fault Reporting Functions, for more information about targets.
BESTlogic Settings for Auxiliary Undervoltage/Overvoltage Protection
BESTlogic settings are made from the BESTlogic Function Element screen in BESTCOMS. Figure 4-26
illustrates the BESTCOMS screen used to select BESTlogic settings for the Undervoltage/Overvoltage
element. (In this case, the auxiliary overvoltage element is shown.) To open the BESTlogic Function
Element screen for Undervoltage/Overvoltage elements, select Voltage Protection from the Screens pull-
down menu. Then select the 27X or the 59X/159X tab. Alternately, settings may be made using SL-59X,
SL-159X, or SL-27X ASCII command.
At the top center of the BESTlogic Function Element 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.
Enable the under/overvoltage function by selecting its mode of operation from the Mode pull-down menu.
To connect the elements 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.
4-30 BE1-700 Protection and Control 9376700990 Rev M