GE L90 Instruction Manual page 472

GROUPED ELEMENTS
There are three neutral overvoltage elements available. The neutral overvoltage element can be used to detect
asymmetrical system voltage condition due to a ground fault or to the loss of one or two phases of the source. The
element responds to the system neutral voltage (3V_0), calculated from the phase voltages. The nominal secondary
voltage of the phase voltage channels entered under
is the p.u. base used when setting the pickup level.
VT SECONDARY
The neutral overvoltage element can provide a time-delayed operating characteristic versus the applied voltage (initialized
from FlexCurves A, B, or C) or be used as a definite time element. The
NEUTRAL OV1 CURVE
VT errors and normal voltage unbalance must be considered when setting this element. This function requires the VTs to
be wye-connected.
5
5.7.14.5 Auxiliary undervoltage (ANSI 27X, IEC PTUV)
SETTINGS  GROUPED ELEMENTS  SETTING GROUP 1(6)  VOLTAGE ELEMENTS  AUXILIARY UV1(3)
 AUXILIARY UV1

The L90 contains one auxiliary undervoltage element for each VT bank. This element monitors undervoltage conditions of
the auxiliary voltage.
The
AUX UV1 PICKUP
voltage of the auxiliary voltage channel entered under
AUXILIARY VT X5 SECONDARY
5-286
setting is "Definite Time." The source assigned to this element must be configured for a phase VT.
Figure 5-158: Neutral overvoltage1 logic
AUX UV1

FUNCTION: Disabled
AUX UV1 SIGNAL

SOURCE: SRC 1
AUX UV1 PICKUP:

0.700 pu
AUX UV1 CURVE:

Definite Time
AUX UV1 DELAY:

1.00 s
AUX UV1 MINIMUM:

VOLTAGE: 0.100 pu
AUX UV1 BLOCK:

Off
AUX UV1 TARGET:

Self-reset
AUX UV1 EVENTS:

Disabled
selects the voltage level at which the time undervoltage element starts timing. The nominal secondary
is the per-unit base used when setting the pickup level.
SETTINGS  SYSTEM SETUP  AC INPUTS  VOLTAGE BANK  PHASE
NEUTRAL OV1 PICKUP DELAY
Range: Disabled, Enabled
Range: SRC 1, SRC 2, SRC 3, SRC 4
Range: 0.004 to 3.000 pu in steps of 0.001
Range: Definite Time, Inverse Time
Range: 0.00 to 600.00 s in steps of 0.01
Range: 0.000 to 3.000 pu in steps of 0.001
Range: FlexLogic operand
Range: Self-reset, Latched, Disabled
Range: Disabled, Enabled
SETTINGS  SYSTEM SETUP  AC INPUTS  VOLTAGE BANK X5 
L90 LINE CURRENT DIFFERENTIAL SYSTEM – INSTRUCTION MANUAL
CHAPTER 5: SETTINGS
setting applies only if the