Negative Sequence - GE Multilin 489 Instruction Manual

5.6.6

Negative Sequence

1 NEGATIVE
SEQUENCE
5–36
Courtesy of NationalSwitchgear.com
•
ENABLE VOLTAGE RESTRAINT:
• : 10%
VOLTAGE LOWER LIMIT
• Phase-Phase Voltage / Rated Phase-Phase Voltage = 0.4 p.u. V
The voltage restrained phase overcurrent pickup level is calculated as follows:
Pickup Phase OC Pickup
=
vrest
( 2 × 0.4 ) CT
=
The 489 phase overcurrent restraint voltages and restraint characteristic are shown below.
Phase Overcurrent Restraint Voltages:
CURRENT VOLTAGE
IA Vab
IB Vbc
IC Vca
808792A4.CDR
FIGURE 5–2: Voltage Restraint Characteristic
PATH: SETPOINTS S5 CURRENT ELEM.
[ ] NEGATIVE SEQUENCE
ALARM: Off
ASSIGN ALARM
MESSAGE
RELAYS (2-5): ---5
NEG. SEQUENCE ALARM
MESSAGE
PICKUP: 3% FLA
NEGATIVE SEQUENCE
MESSAGE
ALARM DELAY: 0.5 s
NEGATIVE SEQUENCE
MESSAGE
ALARM EVENTS: Off
NEGATIVE SEQUENCE
MESSAGE
O/C TRIP: Off
ASSIGN TRIP
MESSAGE
RELAYS (1-4): 1---
NEG. SEQUENCE O/C
MESSAGE
TRIP PICKUP: 8% FLA
NEG. SEQUENCE O/C
MESSAGE
CONSTANT K: 1
NEG. SEQUENCE O/C
MESSAGE
MAX. TIME: 1000 s
"Yes"
× Voltage Rest. Pickup Multiplier
× 0.8 × CT
=
1
0.9
0.8
0.7
0.6
0.5
0.4
0.3
0.2
0.1
0
0 0.1 0.2 0.3 0.4
Phase-Phase Voltage / Rated Phase-Phase Voltage
NEGATIVE SEQUENCE
Range: Off, Latched, Unlatched
Range: Any combination of Relays 2 to
Range: 3 to 100% FLA in steps of 1
Range: 0.1 to 100.0 s in steps of 0.1
Range: On, Off
Range: Off, Latched, Unlatched
Range: Any combination of Relays 1 to
Range: 3 to 100% FLA in steps of 1
Range: 1 to 100 in steps of 1
Range: 10 to 1000 s in steps of 1
489 GENERATOR MANAGEMENT RELAY – INSTRUCTION MANUAL
CHAPTER 5: SETPOINTS
× CT
(EQ 5.9)
0.5 0.6 0.7 0.8 0.9 1
5
4