ABB RET670 Product Manual page 55

ABB
Transformer protection RET670 ANSI
Pre-configured
Product version: 1.2
Table 29. Four step negative sequence overcurrent protection NS4PTOC (46I2)
Function
Operate value, negative
sequence current, step 1-4
Reset ratio
Timers
Inverse characteristics, see table
78, table 79 and table 80
Minimum operate current for step
1 - 4
Operate value, negative current
for directional release
Relay characteristic angle
Minimum polarizing voltage
Minimum polarizing current
Real part of negative sequence
source impedance used for
current polarization
Imaginary part of negative
sequence source impedance
used for current polarization
Operate time, pickup function
Reset time, pickup function
Critical impulse time, pickup
function
Impulse margin time, pickup
function
Transient overreach
Range or value
lBase
(1-2500)% of
> 95%
(0.000-60.000) s
18 curve types
IBase
(1.00 - 10000.00)% of
IBase
(1–100)% of
(-180 to 180) degrees
VBase
(1–100)% of
IBase
(2-100)% of
(0.50-1000.00) W/phase
(0.50–3000.00) W/phase
25 ms typically at 0.5 to 2 x I
set
25 ms typically at 2 to 0.5 x I
set
10 ms typically at 0 to 2 x I
set
15 ms typically
<10% at τ = 100 ms
1MRK 504 118-BUS A
Accuracy
± 1.0% of I at I £ I
n n
± 1.0% of I at I > I
n
-
± 0.5% ± 10 ms
See table 78, table 79 and table
80
± 1.0% of I at I < I
n n
± 1.0% of I at I > I
n
± 1.0% of I
n
± 2.0 degrees
± 0.5% of V
n
±1.0% of I
n
-
-
-
-
-
-
-
55