![background image](http://html.mh-extra.com/html/abb/rex-521/rex-521_technical-reference-manual-standard-configurations_4648234.webp)
234
1MRS751802-MUM
Protection Relay
Technical Reference Manual, Standard Configurations
REX 521
Fig. 11.7.1.-2
Connection overview diagram of the single busbar motor feeder
R
E
X
521
CB
DC
ES
0
1
100V
Uo
A
N
Over
view
Ou
tg
H
0
7
100V
U1
2
100V
U2
3
100V
U3
1
VT
1
CT
1
VT
2
VT
3
VT
4
Io
b
Io
IL
1
IL
2
IL
3
CT
2
CT
3
CT
4
CT
5
5A
1A
5A
1A
5A
1A
5A
1A
1A
0.
2A
L1
L3
L2
27
25
24
22
21
19
18
16
15
13
14
12
10
11
9
7
8
6
4
5
3
1
2
X1
.
1
X4
.
2
5
6
7
8
9
10
12
11
14
13
16
15
18
17
X3
.
1
2
1
X4
.
1
2
1
4
5
3
7
8
6
11
10
9
13
12
14
17
15
18
X4
.
2
3
4
1
2
DI1
DI2
D
I3
DI4
DI5
D
I6
DI7
D
I8
DI9
IRF
S01
S02
P
01
P02
P
03
H
SPO1
TCS1
P1
P2
S1
S2
S1
S2
1
0
M
49
3
60
F
3I
<
37
I2
>
46
46R
3I
3I
48,
14,
66
Is
2
t,n
<
3I
>
50/
51
I >
0
50N
/
51N
f
P
3U
3I
I
0
U
0
Q
E
pf
TC
S
CB
CM
0
I
MC
S
3I
~
har
m
000
R
3U
~
har
m
CB
F
P
*
/
6
2
3U
<
2
7
Circuit-breaker failure
protection
RESTART enable
TRIP circuit breaker
CLOSE circuit breaker
Internal relay fault
Speed Switch
Definite trip alarm
Mains
ACFail
TempAlarm
Prior alarm
Summary of Contents for REX 521
Page 1: ...Protection Relay REX 521 Technical Reference Manual Standard Configurations ...
Page 2: ......
Page 12: ...12 ...
Page 22: ...22 ...
Page 62: ...62 ...
Page 72: ...72 ...
Page 128: ...128 ...
Page 132: ...132 ...
Page 172: ...172 ...
Page 198: ...198 ...
Page 249: ......