Table 46. Four step negative sequence overcurrent protection NS4PTOC
Function Range or value Accuracy
Operate value, negative
sequence current, step 1-4
(1-2500)% of
lBase
± 1.0% of I
r
at I £ I
r
± 1.0% of I at I > I
r
Reset ratio > 95% at (10-2500)% of
IBase
-
Independent time delay for
step 1, 2, 3, and 4 at 0 to 2 x I
set
(0.000-60.000) s ± 0.2% or ± 35 ms whichever is
greater
Inverse characteristics, see
table 117, table 118 and table
119
16 curve types See table 117, table 118 and table
119
Minimum operate current for
steps 1 - 4
(1.00 - 10000.00)% of
IBase
± 1.0% of I
r
at I ≤ I
r
± 1.0% of I at I > I
r
Relay characteristic angle (-180 to 180) degrees
± 2.0 degrees
Operate value, negative
current for directional release
(1–100)% of
IBase
For RCA ± 60 degrees:
± 2.5% of I
r
at I ≤ I
r
± 2.5% of I at I > I
r
Minimum polarizing voltage (1–100)% of
UBase
± 0.5% of U
r
Minimum polarizing current (2-100)% of
IBase
±1.0% of I
r
Real part of negative sequence
source impedance used for
current polarization
(0.50-1000.00) W/phase
-
Imaginary part of negative
sequence source impedance
used for current polarization
(0.50–3000.00) W/phase
-
Operate time, start function at
0 to 2 x I
set
Min = 15 ms
Max = 30 ms
-
Reset time, start function at 2
to 0 x I
set
Min = 15 ms
Max = 30 ms
-
Critical impulse time, start
function
10 ms typically at 0 to 2 x I
set
-
Impulse margin time, start
function
15 ms typically -
Transient overreach <10% at τ = 100 ms -
Transformer protection RET670 2.0
1MRK 504 141-BEN C
Product version: 2.0
ABB 65