GE DGP Series, Instruction Manual

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2-
12
DGP Digital Generator Protection System GE Power Management
2.2 CONFIGURATION SETTINGS 2 CALCULATION OF SETTINGS
2
112: PREFLT – PREFAULT CYCLES
PREFLT selects the number of pre-trigger (or pre-fault) cycles in each oscillography data set. It can be set from
1 to 20. Setting 111: NUM FLTS determines the total number of cycles per storage event, as explained above,
and PREFLT determines how many of these are pre-trigger cycles.
113: OSC TRIG – EXTERNAL OSCILLOGRAPHY TRIGGER
A DGP system trip always causes oscillography to be stored. OSC TRIG enables or disables an additional
oscillography trigger by an external digital input (DI5). Refer to Section 1.4.9: FAULT REPORT & OSCILLOG-
RAPHY DATA on page 1–21 for further explanation. OSC TRIG may be set to 0 (DI ENA) or 1 (DI DIS).
114: NOM VOLT – NOMINAL VOLTAGE
NOM VOLT can be set from 100.0 to 140.0 V (phase-to-phase).
For the sample generator system,
115: RATEDCUR – RATED CURRENT
RATEDCUR can be set from 0.10 to 9.99 A (0.02 to 1.99 A for models with 1 A rating).
For the sample generator system,
116: VT CONN – VOLTAGE TRANSFORMER CONNECTION
VT CONN may be set to 0 (WYE) or 1 (DELTA). VT CONN must be set to identify the VT connections that sup-
ply AC voltage to the DGP.
117: NCTRATIO – NEUTRAL CURRENT TRANSFORMER RATIO
NCTRATIO setting is available in all DGP models except DGP***AAA. It can be set from 1 to 50000. This set-
ting applies to
I
NR
current only; refer to Current Transformer Ratio (Setting 106: CT RATIO) for the CT ratio set-
ting of other current inputs.
For the sample generator system,
2.2.2 EXAMPLE CONFIGURATION SETTINGS
Example Settings (based on Figure 2–1: SAMPLE GENERATOR SYSTEM):
UNITID =1 PHASE = A-B-C (0)
SYSFREQ = 60 TIMESYNC = INTRNL (0)
SEL TVM = as required NUM FLTS = 3
SEL TCM = as required NOM VOLT = 114.3 volts
SELPRIM = PRIMARY (0) RATEDCUR = 4.25 amps
CT RATIO = 1600 VT CONN = WYE (0)
VT RATIO = 157.5 NCTRATIO = 1600
COMMPORT = 2401
NOM VOLT
18000
18900 120
⁄ ( )
----------------------------------- 114.3 V = =
RATEDCUR
211765
1.732 18
× ( )
8000 5
⁄ ( )
---------------------------------------------------------- 4.25 A = =
NCTRATIO
8000
5
-------------
1600
= =