Table 25. Four step phase overcurrent protection OC4PTOC
Function
Setting range
Accuracy
Operate current
(5-2500)% of
lBase
±
1.0% of I
r
at I ≤ I
r
±
1.0% of I at I > I
r
Reset ratio
> 95%
-
Min. operating current
(1-10000)% of
lBase
±
1.0% of I
r
at I ≤ I
r
±
1.0%
of I at I > I
r
Independent time delay
(0.000-60.000) s
±
0.5%
±
25 ms
Minimum operate time
for inverse characteristics
(0.000-60.000) s
±
0.5%
±
25ms
Inverse characteristics,
see table
and
17 curve types
, table
table
Operate time,
nondirectional start
function
20 ms typically at 0 to 2 x I
set
-
Reset time, nondirectional
start function
30 ms typically at 2 to 0 x I
set
-
Operate time, directional
start function
30 ms typically at 0 to 2 x I
set
-
Reset time, directional
start funciton
25 ms typically at 2 to 0 x I
set
-
Critical impulse time
10 ms typically at 0 to 2 x I
set
-
Impulse margin time
15 ms typically
-
Transformer protection RET650
1MRK 504 127-BEN -
Product version: 1.1
Issued: February 2011
ABB
51