Power System - GE L90 Instruction Manual

5.4 SYSTEM SETUP
b) VOLTAGE BANKS
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PATH: SETTINGS SYSTEM SETUP
 VOLTAGE BANK F5

Because energy parameters are accumulated, these values should be recorded and then reset
immediately prior to changing VT characteristics.
Two banks of phase/auxiliary VTs can be set, where voltage banks are denoted in the following format (X represents the
module slot position letter):
Xa, where X = {F, L} and a = {5}.
5
See the Introduction to AC sources section at the beginning of this chapter for additional details.
With VTs installed, the relay can perform voltage measurements as well as power calculations. Enter the
made to the system as "Wye" or "Delta". An open-delta source VT connection would be entered as "Delta".
NECTION
The nominal
PHASE VT F5 SECONDARY
voltage is applied to the VT primary.
NOTE
For example, on a system with a 13.8 kV nominal primary voltage and with a 14400:120 volt VT in a delta connec-
tion, the secondary voltage would be 115; that is, (13800 / 14400) × 120. For a wye connection, the voltage value
entered must be the phase to neutral voltage which would be 115 
On a 14.4 kV system with a delta connection and a VT primary to secondary turns ratio of 14400:120, the voltage
value entered would be 120; that is, 14400 / 120.

PATH: SETTINGS SYSTEM SETUP
 POWER SYSTEM

The power system
NOMINAL FREQUENCY
cannot be measured from available signals. This may happen if the signals are not present or are heavily distorted. Before
reverting to the nominal frequency, the frequency tracking algorithm holds the last valid frequency measurement for a safe
period of time while waiting for the signals to reappear or for the distortions to decay.
5-74
 
AC INPUTS
PHASE VT F5
CONNECTION: Wye
PHASE VT F5
MESSAGE
SECONDARY: 66.4 V
PHASE VT F5
MESSAGE
RATIO: 1.00 :1
AUXILIARY VT F5
MESSAGE
CONNECTION: Vag
AUXILIARY VT F5
MESSAGE
SECONDARY: 66.4 V
AUXILIARY VT F5
MESSAGE
RATIO: 1.00 :1
voltage setting is the voltage across the relay input terminals when nominal


POWER SYSTEM

NOMINAL FREQUENCY:
60 Hz
PHASE ROTATION:
MESSAGE
ABC
FREQUENCY AND PHASE
MESSAGE
REFERENCE: SRC 1
FREQUENCY TRACKING:
MESSAGE
Enabled
value is used as a default to set the digital sampling rate if the system frequency
L90 Line Current Differential System
VOLTAGE BANK F5(L5)
Range: Wye, Delta
Range: 25.0 to 240.0 V in steps of 0.1
Range: 1.00 to 24000.00 in steps of 0.01
Range: Vn, Vag, Vbg, Vcg, Vab, Vbc, Vca
Range: 25.0 to 240.0 V in steps of 0.1
Range: 1.00 to 24000.00 in steps of 0.01
3 = 66.4.
Range: 25 to 60 Hz in steps of 1
Range: ABC, ACB
Range: SRC 1, SRC 2, SRC 3, SRC 4
Range: Disabled, Enabled
5 SETTINGS
PHASE VT F5 CON-
5.4.2 POWER SYSTEM
GE Multilin