Inverse characteristic
M12388-1 v17
Table 163. ANSI Inverse time characteristics
Function
Range or value
Accuracy
Operating characteristic:
(
)
1
P
A
t
B k tDef
I
æ
ö
ç
÷
=
+
× +
ç
÷
ç
-
÷
è
ø
EQUATION1249-SMALL V2 EN-US
Reset characteristic:
( )
2
1
=
×
-
tr
t
k
I
EQUATION1250-SMALL V1 EN-US
I = I
measured
/I
set
0.10 ≤ k ≤ 3.00
1.5 x I
set
≤ I ≤ 20 x I
set
ANSI/IEEE C37.112 ,
±2.0% or ±40 ms
whichever is greater
ANSI Extremely Inverse
A=28.2, B=0.1217, P=2.0 , tr=29.1
ANSI Very inverse
A=19.61, B=0.491, P=2.0 , tr=21.6
ANSI Normal Inverse
A=0.0086, B=0.0185, P=0.02, tr=0.46
ANSI Moderately Inverse
A=0.0515, B=0.1140, P=0.02, tr=4.85
ANSI Long Time Extremely Inverse
A=64.07, B=0.250, P=2.0, tr=30
ANSI Long Time Very Inverse
A=28.55, B=0.712, P=2.0, tr=13.46
ANSI Long Time Inverse
A=0.086, B=0.185, P=0.02, tr=4.6
1MRK 502 068-BEN D
Generator protection REG670 2.1 IEC
Product version: 2.1
ABB
107
