GE LPS-O, Instruction Manual

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GE Power Management LPS-O Line Protection System 2-
23
2 CALCULATION OF SETTINGS 2.3 PROTECTION SETTINGS
2
2.3.12 SCHEME TIMERS
1101: TL5PICKUP - BKR1 b sw Coordination Timer Pickup
1102: TL5DROPOUT - BKR1 b sw Coordination Timer Dropout
1103: TL6PICKUP - BKR2 b sw Coordination Timer Pickup
1104: TL6DROPOUT - BKR2 b sw Coordination Timer Dropout
Pickup and Dropout time settings of the timers TL5 and TL6 can be used, if desired, to coordinate the Time
Tags of breaker position events with the main contacts of the breaker. There is no other significance of these
settings in the LPS-O.
2.3.13 LINE INFO
1201: POSSEQANG - Positive Sequence Impedance Angle
POSSEQANG is common to all of the distance functions and establishes the positive sequence angle of max-
imum reach. Set POSSEQANG to a value that is equal to or just larger than the angle of the positive-sequence
impedance of the protected line.
1202: CTRATIO - Current Transformer Ratio
The LPS-O system will report present values in terms of secondary values or primary values as set by General
Setting 108: DISPLAYVAL. The ratio of the of the current transformers used to supply the system is used in
this procedure. Set CTRATIO equal to the CT ratio used with the LPS-O system.
1203: PTRATIO - Potential Transformer Ratio
The LPS-O system will report present values in terms of secondary values or primary values as set by General
Setting 108: DISPLAYVAL. The ratio of the of the potential transformers used to supply the system is used in
this procedure. Set PTRATIO equal to the PT ratio used with the LPS-O system.
1204: TRSFMRTYPE - Transformer Type
TRSFMRTYPE can be set as NONE, YD1, YD5, YD7, or YD11. It should be set to properly describe the phase
shift between the Delta (
∆
) and Wye (Y) sides of the Generator Step-up Transformer that may exist between
the LPS-O and the protected line/system. Figure 2–10: PROTECTION SETTING 1204: TRSMFRTYPE below
shows different transformer configurations and appropriate settings for TRSMFRTYPE.
Figure 2–10: PROTECTION SETTING 1204: TRSMFRTYPE
L P S - O
G
Y
∆
Generator Step-up
Transformer
Tripping Direction
Power System
IF: Protection Setting 1204:
No Transformer NONE
∆
side lags Y by 30° YD1
∆
side lags Y by 150° YD5
∆
side leads Y by 150° YD7
∆
side leads Y by 30° YD11