Basler Electric BE1-11g - Manual (Page 152)

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Bus CT Configuration
On protection systems equipped with two sets of CTs, the 78OOS element can monitor CT circuit 1 or CT
circuit 2. The CT source is selected on the Sensing Transformers settings screen in BESTCOMSPlus.
Pickup and Trip
The Pickup output occurs first, followed by the Trip output.
Pickup
The MHO Pickup output and Blinder A Pickup output become true when the calculated impedance (V1/I1)
moves inside the mho circle.
The Blinder B Pickup output becomes true when the calculated impedance moves to the left of Blinder B
while inside the mho circle. Assertion of the Blinder B Pickup output initiates a timer. The duration of the
timer is established by the Blinder Traverse Time Delay setting.
The Pickup output becomes true if the calculated impedance moves to the left of Blinder A, while inside
the mho circle and after the Blinder Traverse Time Delay expires. In BESTlogicPlus, the Pickup output
can be connected to other logic elements to annunciate the condition, control other elements in logic, and
start the fault recorder (logic element FAULTTRIG).
Assertion of the Pickup output initiates a timer that begins timing to a trip. The duration of the timer is
established by the Trip Delay setting. A Trip Delay of zero (0) makes the 78OOS element instantaneous
with no intentional time delay.
If the pickup condition subsides before the element delay expires, the timer and Pickup output are reset,
no corrective action is taken, and the element is rearmed for any other out-of-step conditions.
Trip
The Trip output becomes true if an out-of-step condition persists for the duration of the element Trip Delay
setting. In BESTlogicPlus, the Trip output can be connected to other logic elements and to a physical
relay output to annunciate the condition and to initiate corrective action. If a target is enabled for the
element, the BE1-11g will record a target when the Trip output becomes true. See the
Fault Reporting
chapter for more information about target reporting.
Element Blocking
The Block input provides logic-supervision control of the element. When true, the Block input disables the
element by forcing the Trip and Pickup outputs to logic 0 and resetting the element timer. Connect the
element Block input to the desired logic in BESTlogicPlus. When the element is initially selected from the
Elements view, the default condition of the Block input is a logic 0.
Logic Connections
Out of step element logic connections are made on the BESTlogicPlus screen in BESTCOMSPlus. The
out of step element logic block is illustrated in Figure 89. Logic inputs and outputs are summarized in
Table 52.
Out of Step (78OOS) Protection BE1-11g