Voltage Restrained Overcurrent Test - GE 489 Instruction Manual

7.3 ADDITIONAL FUNCTIONAL TESTING
1. Alter the following setpoints.
S2 SYSTEM SETUP\GEN. PARAMETERS\GENERATOR SETTING:
S2 SYSTEM SETUP\GEN. PARAMETERS\GENERATOR VOLTAGE PHASE-PHASE:
S2 SYSTEM SETUP\VOLTAGE SENSING\VT CONNECTION TYPE:
S2 SYSTEM SETUP\VOLTAGE SENSING\VOLTAGE TRANSFORMER RATIO:
S5 CURRENT ELEMENTS\OVERCURRENT ALARM\OVERCURRENT ALARM:
S5 CURRENT ELEMENTS\OVERCURRENT ALARM\O/C ALARM LEVEL:
S5 CURRENT ELEMENTS\OVERCURRENT ALARM\OVERCURRENT ALARM DELAY:
S5 CURRENT ELEMENTS\OVERCURRENT ALARM\O/C ALARM EVENTS:
S5 CURRENT ELEMENTS\PHASE OVERCURRENT\PHASE OVERCURRENT TRIP:
S5 CURRENT ELEMENTS\PHASE OVERCURRENT\ENABLE VOLTAGE RESTRAINT:
S5 CURRENT ELEMENTS\PHASE OVERCURRENT\PHASE O/C PICKUP:
S5 CURRENT ELEMENTS\PHASE OVERCURRENT\CURVE SHAPE:
S5 CURRENT ELEMENTS\PHASE OVERCURRENT\O/C CURVE MULTIPLIER:
S5 CURRENT ELEMENTS\PHASE OVERCURRENT\O/C CURVE RESET:
2. The trip time for the extremely inverse ANSI curve is given as:
Time to Trip = M
where: M =
O/C CURVE MULTIPLIER
A , B , C , D , E = curve constants; A = 0.0399, B = 0.2294, C = 0.5000, D = 3.0094, E = 0.7222
K = voltage restrained multiplier <optional>
The voltage restrained multiplier is calculated as
3. Using Figure 7–4: SECONDARY INJECTION TEST SETUP #3 on page 7–15, inject current and apply voltage as per
the table below. Verify the alarm/trip elements and view the event records in
CURRENT/VOLTAGE (5 A UNIT)
CURRENT
Ian = 5 A∠0°
Ibn = 5 A∠120° lag
7
Icn = 5 A∠240° lag
Ian = 6 A∠0°
Ibn = 6 A∠120° lag
Icn = 6 A∠240° lag
Ian = 10 A∠0°
Ibn = 10 A∠120° lag
Icn = 10 A∠240° lag
Ian = 10 A∠0°
Ibn = 10 A∠120° lag
Icn = 10 A∠240° lag
Ian = 10 A∠0°
Ibn = 10 A∠120° lag
Icn = 10 A∠240° lag
 activated;  Not Activated
7-16

B D

A
+ ------------------------------ + -------------------------------------- -
×

I 
I
------------------- - C –
 ------------------- - C

〈 〉 ×
〈 〉 ×
K I
K I

p
p
setpoint, I = input current, I
VOLTAGE EXPECTED OBSERVED
Vab = 120 V∠0° lag

Vbc = 120 V∠120° lag
Vca = 120 V∠240° lag
Vab = 120 V∠0°

Vbc = 120 V∠120° lag
Vca = 120 V∠240° lag
Vab = 120 V∠0°

Vbc = 120 V∠120° lag
Vca = 120 V∠240° lag
Vab = 100 V∠0°

Vbc = 100 V∠120° lag
Vca = 100 V∠240° lag
Vab = 60 V∠0°

Vbc = 60 V∠120° lag
Vca = 60 V∠240° lag
489 Generator Management Relay

7.3.10 VOLTAGE RESTRAINED OVERCURRENT TEST

100 MVA
12000
Open Delta
100:1
Unlatched
1.10 x FLA
2 s
On
Latched
Yes
1.5 x CT
ANSI Extremely Inv.
2.00
Instantaneous

E

+ -------------------------------------- -

 2   3
I
------------------- - C 
– –
  
〈 〉 ×
K I

p
=
PHASE O/C PICKUP
p
phase-to-phase voltage
K = ----------------------------------------------------------------------------- -
rated phase-to-phase voltage
A5 EVENT RECORD
ALARM
DELAY EXPECTED OBSERVED EXPECTED OBSERVED
N/A



7 TESTING
setpoint
and has a range of 0.1 to 0.9.
TRIP TRIP DELAY

N/A

N/A
11.8 sec.
6.6 sec.
1.7 sec.
GE Power Management
N/A
N/A