GUID-2AE8C92E-5DA8-487F-927D-8E553EE29240 v3
Table 227. ANSI Inverse time characteristics for Voltage restrained time overcurrent protection
Function
Range or value
Accuracy
Operating characteristic:
(
)
1
P
A
t
B
k
I
=
+
⋅
−
EQUATION1249-SMALL V3 EN-US
Reset characteristic:
( )
2
1
=
×
-
tr
t
k
I
EQUATION1250-SMALL V1 EN-US
I = I
measured
/I
set
0.05 ≤ k ≤ 999.00
ANSI/IEEE C37.112 , ±
5.0% 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
Long Time Extremely Inverse
A=64.07, B=0.250, P=2.0, tr=30
Long Time Very Inverse
A=28.55, B=0.712, P=2.0, tr=13.46
Long Time Inverse
A=0.086, B=0.185, P=0.02, tr=4.6
Table 228. IEC Inverse time characteristics for Voltage restrained time overcurrent protection
Function
Range or value
Accuracy
Operating characteristic:
(
)
1
=
×
-
æ
ö
ç
÷
ç
÷
è
ø
P
A
t
k
I
EQUATION1251-SMALL V1 EN-US
I = I
measured
/I
set
0.05 ≤ k ≤ 999.00
IEC 60255-151, ±5.0%
or ±40 ms whichever is
greater
IEC Normal Inverse
A=0.14, P=0.02
IEC Very inverse
A=13.5, P=1.0
IEC Inverse
A=0.14, P=0.02
IEC Extremely inverse
A=80.0, P=2.0
IEC Short time inverse
A=0.05, P=0.04
IEC Long time inverse
A=120, P=1.0
Line differential protection RED670
1MRK 505 379-BEN R
Version 2.2
164
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