# Power System - GE UR Series Instruction Manual

Line differential relay.

5 SETTINGS
b) VOLTAGE BANKS
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PATH: SETTINGS
SYSTEM SETUP
VOLTAGE BANK X5
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'X' = F, M, or U. 'F', 'M', and 'U' are module slot position letters. See also the INTRODUCTION TO AC SOURCES section.
Up to 3 banks of phase/auxiliary VTs can be set.
With VTs installed, the relay can be used to 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
VT xx CONNECTION
"Delta". See the typical wiring diagram in the HARDWARE chapter for details.
The nominal Phase VT Secondary Voltage setting is the voltage across the relay input terminals when nominal volt-
age 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, i.e. (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, i.e. 14400 / 120.
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PATH: SETTINGS
SYSTEM SETUP

## POWER SYSTEM

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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.
The phase sequence of the power system is required to properly calculate sequence components and power parameters.
The
setting matches the power system phase sequence. Note that this setting informs the relay of the
PHASE ROTATION
actual system phase sequence, either ABC or ACB. CT and VT inputs on the relay, labeled as A, B, and C, must be con-
nected to system phases A, B, and C for correct operation.
GE Power Management
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AC INPUTS
VOLTAGE BANK X1
PHASE VT X5
CONNECTION: Wye
PHASE VT X5
SECONDARY: 66.4 V
PHASE VT X5
RATIO: 1.00 :1
AUXILIARY VT X5
CONNECTION: Vag
AUXILIARY VT X5
SECONDARY: 66.4 V
AUXILIARY VT X5
RATIO: 1.00 :1
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POWER SYSTEM
NOMINAL FREQUENCY:
60 Hz
PHASE ROTATION:
ABC
FREQUENCY AND PHASE
REFERENCE: SRC 1
FREQUENCY TRACKING:
Enabled
value is used as a default to set the digital sampling rate if the system frequency
L90 Line Differential Relay
5.3 SYSTEM SETUP
Range: Wye, Delta
Range: 50.0 to 240.0 V in steps of 0.1
Range: 1.00 to 24000.00 in steps of 1.00
Range: Vn, Vag, Vbg, Vcg, Vab, Vbc, Vca
Range: 50.0 to 240.0 V in steps of 0.1
Range: 1.00 to 24000.00 in steps of 1.00
3
= 66.4.
5.3.2 POWER SYSTEM
Range: 25 to 60 Hz in steps of 1
Range: ABC, ACB
Range: SRC 1, SRC 2,..., SRC 6
Range: Disabled, Enabled
PHASE
5
5-25