Siemens Argus 7SR21 Technical Manual page 583

3.4 Broken Conductor. (46BC)
I
L1
(I )
A
I
L2
(I )
B
I
L3
(I )
C
I
4
(I )
G
I
5
(I )
SEF
V
L1
(V )
A
V
L2
(V )
B
V
L3
(V )
C
V
4
(V )
X
Voltage Inputs:
Current Inputs:
Disable:
Map Pickup LED:.
Broken Conductor uses the ratio of NPS current to PPS current to detect an open circuit conductor. These
quantities can be produced directly from many advanced test sets but with limited equipment the following
approach can be applied.
Apply 3P balanced current with normal phase rotation direction. This current will consist of PPS alone, no NPS or
ZPS.
Increase 1 phase current magnitude in isolation to produce NPS. The single phase unbalance current will contain
equal quantities of ZPS, NPS and PPS. The NPS component will be 1/3 of the unbalance current and the total
PPS component will be value of the original balanced 3P current plus 1/3 of the additional unbalance current. i.e.
as the single phase unbalance current increases, the ratio of NPS to PPS will also increase. The levels of each
sequence component current can be monitored in the Current Meters in Instruments Mode.
© 2013 Siemens Protection Devices Limited
37 50
49
(x2) BF
37 50
49
(x2) BF
37 50
49
(x2) BF
46
46 60
NPS
BC CTS
(x2)
50
37
BF
50
37
BF
NOTE: The use of some
functions are mutually exclusive
27
59
(x4)
27
47
59
(x2)
(x4)
27
59
(x4)
27
59
Optional
79 25
Figure 3.4-1
n/a
I (I ), I (I ), I
L1 A L2 B L3
51N, 46IT, 46DT
46BC - Self Reset
7SR210 & 7SR220 Commissioning & Maintenance Guide
7SR22
60 67/ 67/
50
CTS- 51V 50 51
AFD
I (x4) (x4)
67/ 67/
60
50
51V 50 51
CTS-
AFD
I (x4) (x4)
67/ 67/
60
50
51V 50 51
CTS-
AFD
(x4) (x4)
I
67/ 67/
60
50N 51N
51c
VTS
(x4) (x4)
67/ 67/
50G 51G
(x4) (x4)
67/ 67/
64
50S 51S
H
(x4) (x4)
81
(x6)
59N 74
(x2) TCS
Broken Conductor
(I ),
C
81
51c HBL
2
81
51c HBL
2
81
51c HBL
2
81
HBL
2N
37G
(x2)
37S
(x2)
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