GE UR Series B30 Instruction Manual page 263

5 SETTINGS
Using the drop-out undervoltage operand as the Block input to the differential element is not recommended. The differential
element includes the saturation detector that responds to certain time relationships between the differential and restraining
currents, and therefore, it must be operational all the time in order to function properly.
This element may be used to give a desired time-delay operating characteristic versus the applied fundamental voltage
(phase-to-ground or phase-to-phase for wye VT connection, or phase-to-phase for delta VT connection) or as a definite
time element. The element resets instantaneously if the applied voltage exceeds the dropout voltage. The delay setting
selects the minimum operating time of the phase undervoltage. The minimum voltage setting selects the operating voltage
below which the element is blocked (a setting of "0" will allow a dead source to be considered a fault condition).
SETTING
PHASE UV1
FUNCTION:
Disabled = 0
Enabled = 1
SETTING
AND
PHASE UV1
BLOCK:
Off = 0
SETTING
}
PHASE UV1 SOURCE:
Source VT = Delta
VAB
VBC
VCA
Source VT = Wye
SETTING
PHASE UV1 MODE:
Phase to Ground Phase to Phase
VAG VAB
VBG VBC
VCG VCA
GE Multilin
SETTING
PHASE UV1
MINIMUM VOLTAGE:
<
VAG or VAB Minimum
<
VBG or VBC Minimum
<
VCG or VCA Minimum
Figure 5–62: PHASE UNDERVOLTAGE1 SCHEME LOGIC
B30 Bus Differential System
SETTING
PHASE UV1
PICKUP:
PHASE UV1
CURVE:
PHASE UV1
DELAY:
<
AND RUN VAG or VAB PICKUP
t
V
<
AND RUN VBG or VBC PICKUP
t
V
<
AND RUN VCG or VCA PICKUP
t
V
5.6 GROUPED ELEMENTS
FLEXLOGIC OPERANDS
PHASE UV1 A PKP
PHASE UV1 A DPO
PHASE UV1 A OP
PHASE UV1 B PKP
PHASE UV1 B DPO
PHASE UV1 B OP
PHASE UV1 C PKP
PHASE UV1 C DPO
PHASE UV1 C OP
FLEXLOGIC OPERAND
OR PHASE UV1 PKP
FLEXLOGIC OPERAND
OR PHASE UV1 OP
FLEXLOGIC OPERAND
AND PHASE UV1 DPO
827039AB.CDR
5-139
5