beautypg.com

Bus ct configuration, Pickup and trip, Element blocking – Basler Electric BE1-11g User Manual

Page 140: Logic connections

background image

128

9424200994 Rev N

Bus CT Configuration

On protection systems equipped with two sets of CTs, the 40Q 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 Pickup output becomes true when the calculated reactive power increases above or decreases below
the threshold established by the Pickup setting. 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 Time Delay setting. A Time Delay setting of zero (0) makes the 40Q 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 occurrences of loss of excitation.

Trip

The Trip output becomes true if a loss of excitation pickup condition exists for the duration of the element
Time Delay. 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

Loss of excitation - reverse var based element logic connections are made on the BESTlogicPlus screen
in BESTCOMSPlus. The loss of excitation - reverse var based element logic block is illustrated in Figure
81.
Logic inputs and outputs are summarized in Table 46.

Figure 81. Loss of Excitation - Reverse var Based Element Logic Block

Table 46. Logic Inputs and Outputs

Name

Logic Function

Purpose

Block

Input

Disables the 40Q function when true

Trip

Output

True when the 40Q element is in a trip condition

Pickup

Output

True when the 40Q element is in a pickup condition

Loss of Excitation - Reverse Var Based (40Q) Protection

BE1-11g