GE DGP Series - 112: Preflt - Prefault Cycles; 113: Osc Trig - External Oscillography Trigger; 114: Nom Volt - Nominal Voltage; 115: Ratedcur - Rated Current

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
==