ABB RET670 - Page 108

Section 1
Operate
conditionally
UnrestrainedLimit
Section 2
Section 3
Restrain
Operate
unconditionally
5
4
3
2
1
0
0 1 2 3 4 5
IdMin
EndSection1
EndSection2
restrain current
[ times IBase ]
operate current
[ times IBase ]
SlopeSection2
SlopeSection3
en05000187-2.vsd
IEC05000187 V2 EN
Figure 25: Representation of the restrained-, and the unrestrained operate
characteristics
100%
Ioperate
slope
Irestrain
D
=
D
×
EQUATION1246 V1 EN
(Equation 29)
and where the restrained characteristic is defined by the settings:
1. IdMin
2. EndSection1
3. EndSection2
4. SlopeSection2
5. SlopeSection3
Section 3 1MRK504116-UUS C
IED application
102
Application manual