5-68 G650 Generator Protection & Control System GEK-113285A
5.4 PROTECTION ELEMENTS 5 SETTINGS
5.4.9.6 AUXILIARY UNDERVOLTAGE ELEMENT (27X)
This is an Auxiliary undervoltage element for general use that uses as its input magnitude the voltage measured by the 4
th
VT, terminals A11-A12 (when VX is selected as Auxiliary Voltage in General Settings).
Table 5–70: 27X ELEMENT SETTINGS
The snapshot event setting enables or disables the snapshot event generation for this element.
5.4.9.7 VOLTS / HERTZ (24) (ENHANCED MODELS ONLY)
The Volt/Hertz elements can be used for generator protection. The element is active as soon as the magnitude and
frequency of the voltage selected in the “V/Hz source” setting is measurable. This setting can be selected between
PHASES or AUX VOLTAGE. The element uses for its calculations the voltage and frequency selected in “V/Hz Source”
setting. When the setting selected is “PHASES” the function uses for its calculations the maximum of the three phase
voltages available. When the setting selected is “AUX VOLTAGE” the voltage used is the one measured through the fourth
voltage transformer (A11-A12).
The element has a linear reset characteristic. The reset time can be programmed to match the cooling characteristics of the
protected equipment. The element will fully reset from the trip threshold in Volts/Hz T-Reset seconds. The V/Hz element
may be used as an instantaneous element with no intentional time delay or as a Definite or Inverse timed element.
The per unit value for this element is established as per voltage and nominal frequency power system settings as follows:
• Nominal Voltage setting is located in “Setpoint>System Setup>General Settings>Nominal Voltage”
• Nominal Frequency setting is located in “Setpoint>System Setup>General Settings>Nominal Frequency”
SETPOINT > PROTECTION ELEMENTS > VOLTAGE ELEMENTS > AUXILIARY UV >
AUXILIARY UV 1> AUXILIARY UV 2 > AUXILIARY UV 3
setting Description Name Default Value Step Range
Function permission Function DISABLED N/A [DISABLED – ENABLED]
Pickup Level Pickup Level 10 1 V [3 : 500]
Curve shape Curve DEFINITE TIME N/A [DEFINITE TIME – INVERSE TIME]
Time Dial Delay 10.00 0.01 s [0.00 : 900.00]
Snapshot Event generation Snapshot Events ENABLED N/A [DISABLED – ENABLED]
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