ABB 1MRK002826-AG - Page 135

GUID-2AE8C92E-5DA8-487F-927D-8E553EE29240 v2
Table 188. ANSI Inverse time characteristics for Voltage restrained time overcurrent protection
Function Range or value Accuracy
Operating characteristic:
( )
1
P
A
t Bk
I


= +⋅

−

EQUATION1249-SMALL V3 EN-US
Reset characteristic:
( )
2
1
= ×
-
t
r
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
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
Table 189. 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
Generator protection REG670
1MRK 502 074-BEN M
Version 2.2
Hitachi Power Grids 135
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