3RU11, 3RB10, and 3RB12 overload relays
SIRIUS System Manual
GWA 4NEB 430 0999-02b
4-21
Tripping characteristics
The time-current characteristic for three-pole symmetric loading shows the
dependency of the tripping time from a cold state on the multiple of the set
current.
When the overload relay is preloaded with 100 % of the set current, the trip-
ping times are reduced.
In the case of two-pole loading (loss of a phase) or current imbalance
> 40 % of the set current, the corresponding characteristic applies.
Figure 4-11: Time-current characteristics, chart for the 3RB12
3RB12 electronic overload relay with analog output
Field of application
The electronic overload relay with analog output is used for measuring
instruments and analog modules with 4 to 20 mA input.
Figure 4-12: Electronic overload relay with analog output, front view
For automatic resetting, jumper B is attached between terminals Y1 and Y2.
Three-pole loading
Two-pole loading
120
100
50
20
10
5
2
1
50
20
10
5
2
1
2
5
10x
I
e
mi
n
s
0,6
CLASS 30
25
20
15
10
CLASS 5
Tr
ip
p
in
g
ti
m
e
Tripping current (mean values)
120
100
50
20
10
5
2
1
50
20
10
5
2
1
2
5
10x
I
e
mi
n
s
0,6
CLASS 30
25
20
15
10
CLASS 5
T
ri
p
p
ing t
im
e
Tripping current (mean values)
AC220-240V
Overload
Reset
4 ... 20 mA
Gnd Fault
J
Gnd Fault
Ready
Test/
Reset
3RB1
G/9401
3RB1246-1EM40
Overload
Gnd Fault
NC
NO
A1
NO
NC
A2
98
06
97
96
95
05
08
07
Class
C2
T1
+
-
5
Y2
Y1
Overload
T2/C1
25
30
40
50
60
70
80
90
100
10
15
20
25
30
A
B
A