ABB Relion 670 series, Technical Reference Manual

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definite time delay. Thus, if only the inverse time delay is required, it is
of utmost importance to set the definite time delay for that stage to zero.
22.3 Inverse characteristics
Table 728: ANSI Inverse time characteristics
Function Range or value Accuracy
Operating characteristic:
( )
= + ×
-
æ ö
ç ÷
ç ÷
è ø
1
P
A
t B td
I
EQUATION1651 V1 EN
Reset characteristic:
( )
= ×
-
2
1
tr
t td
I
EQUATION1652 V1 EN
I = I
measured
/I
set
td = (0.05-999) in steps of 0.01 -
ANSI Extremely Inverse A=28.2, B=0.1217, P=2.0 , tr=29.1 ANSI/IEEE C37.112, 5%
+ 40 ms
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
Section 22
1MRK505222-UUS C
Inverse time characteristics
1188
Technical reference manual