ABB RET670 - IEC Inverse Time Characteristics; RI and RD Type Inverse Time Characteristics

Table 118. IEC Inverse time characteristics
Function Range or value Accuracy
Operating characteristic:
( )
1
= ×
-
æ ö
ç ÷
ç ÷
è ø
P
A
t k
I
EQUATION1251-SMALL V1 EN
I = I
measured
/I
set
k = (0.05-2.00) in steps of 0.01 IEC 60255-151, ± 2.0%
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
Programmable characteristic
Operate characteristic:
( )
= + ×
-
æ ö
ç ÷
ç ÷
è ø
P
A
t B k
I C
EQUATION1370-SMALL V1 EN
Reset characteristic:
( )
= ×
-
PR
TR
t k
I CR
EQUATION1253-SMALL V1 EN
I = I
measured
/I
set
k = (0.05-999) in steps of 0.01
A=(0.005-200.000) in steps of 0.001
B=(0.00-20.00) in steps of 0.01
C=(0.1-10.0) in steps of 0.1
P=(0.005-3.000) in steps of 0.001
TR=(0.005-100.000) in steps of 0.001
CR=(0.1-10.0) in steps of 0.1
PR=(0.005-3.000) in steps of 0.001
Table 119. RI and RD type inverse time characteristics
Function
Range or value Accuracy
RI type inverse characteristic
1
0.236
0.339
= ×
-
t k
I
EQUATION1137-SMALL V1 EN
I = I
measured
/I
set
k = (0.05-2.00) in steps of 0.01 IEC 60255-151, ± 2.0%
or ± 40 ms whichever is
greater
RD type logarithmic inverse characteristic
5.8 1.35= - ×
æ ö
ç ÷
è ø
t
I
In
k
EQUATION1138-SMALL V1 EN
I = I
measured
/I
set
k = (0.05-999) in steps of 0.01
Transformer protection RET670 2.0
1MRK 504 141-BEN C
Product version: 2.0
100 ABB