ABB RET670 Product Manual page 59

ABB
Transformer protection RET670
Customized
Product version: 1.2
Table 45. Four step negative sequence overcurrent protection NS4PTOC
Function
Operate value, negative
sequence current, step 1-4
Reset ratio
Timers
Inverse characteristics, see table
109, table 110 and table 111
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, start function
Reset time, start function
Critical impulse time, start
function
Impulse margin time, start
function
Transient overreach
Range or value
(1-2500)% of lBase
> 95%
(0.000-60.000) s
18 curve types
IBase
(1.00 - 10000.00)% of
(1–100)% of IBase
(-180 to 180) degrees
UBase
(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 504 117-BEN D
Accuracy
± 1.0% of I at I £ I
r r
± 1.0% of I at I > I
r
-
± 0.5% ± 10 ms
See table 109, table 110 and
table 111
± 1.0% of I at I < I
r r
± 1.0% of I at I > I
r
± 1.0% of I
r
± 2.0 degrees
± 0.5% of U
r
±1.0% of I
r
-
-
-
-
-
-
-
59