Basler BE1-11g, Instruction Manual

Page: 71 / 706

9424200994 Rev U 59
BE1-11 g Phase Undervoltage (27P) Protection
Figure 44. Time Undervoltage Characteristic Curves
Pickup and Trip
The Pickup output occurs first, followed by the Trip output.
Pickup
The Pickup output becomes true when the measured voltage decreases below the voltage threshold
established by the Pickup setting. In BESTlogic
Plus , 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 (definite timing) or Time Dial (inverse timing). A Time Delay or Time Dial
setting of zero (0) makes the 27P element instantaneous with no intentional time delay.
If the pickup condition subsides before the element delay or calculated inverse time expires, the timer and
Pickup output are reset, no corrective action is taken, and the element is rearmed for any other
occurrences of undervoltage.
Trip
The Trip output becomes true when an undervoltage pickup condition persists for the duration of the
element Time Delay setting or calculated inverse time. In BESTlogic
Plus , 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 BE1-11
g
will record a target when the Trip
output becomes true. See the Fault Reporting chapter for more information about target reporting.
Voltage Inhibit
The Voltage Inhibit setting impedes phase undervoltage element operation during undervoltage
conditions that may occur during equipment startup. This setting is expressed in primary or secondary
voltage depending on the Settings Display Mode selected on the General Settings/Display Units settings
screen in BESTCOMS
Plus. Its unit of measure depends upon the phase VT connection setting. For four-
wire or phase-to-neutral sensing connections, the inhibit level is expressed in Vpn. For three-wire or
phase-to-phase sensing connections the inhibit level is expressed in Vpp.