Siemens Argus 7SR11, Manual

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7SR11 & 7SR12 Commissioning and Maintenance Guide
©2017 Siemens Protection Devices Limited Chapter 6 Page 14 of 72
2.2 Phase Overcurrent (67/50,67/51)
7SR12
46
BC
46
NPS
(x2)
37
(x2)
49
50
BF
51V
V
L1
(V
A
)
V
L2
(V
B
)
V
L3
(V
C
)
I
L1
(I
A
)
81
HBL
2
37
(x2)
49
50
BF
51V
I
L2
(I
B
)
81
HBL
2
37
(x2)
49
50
BF
51V
I
L3
(I
C
)
81
HBL
2
I
4
(I
G
)
74
T/
CCS
NOTE: The use of some
functions are mutually exclusive
67/
50
(x4)
67/
51
(x4)
67/
50N
(x4)
67/
50
(x4)
67/
50
(x4)
67/
51
(x4)
67/
51
(x4)
67/
51N
(x4)
67/
50G
(x4)
67/
51G
(x4)
27
59
(x4)
27
59
(x4)
27
59
(x4)
79
Optional
Note:
Example shows
Voltage Config =
Van, Vbn, Vcn
60
CTS
60
VTS
50BF 64H
51c
51c
51c
47
(x2)
59N
(x2)
81
(x4)
Figure 2-2 Phase Overcurrent
Voltage Inputs: V
L1
(V
A
), V
L2
(V
B
), V
L3
(V
C
) for directional elements.
Current Inputs: I
L1
(I
A
), I
L2
(I
B
), I
L3
(I
C
),
Disable: 51V, 51C, 46, 49, 50CBF, 79
Map Pickup LED: 51-n/50-n - Self Reset
Other protection functions may overlap with these functions during testing, it may be useful to disable some
functions to avoid ambiguity. It should be particularly noted that if the function is enabled, the 51C Cold Load
settings may modify the normal 50-n and 51-n settings if the CB is open during testing.
Voltage inputs may not be required for this function if the Phase Overcurrent functions are not directional but it
may be advantageous to apply balanced 3 phase nominal rated voltage to the VT inputs during testing to avoid
inadvertent operation of other functions. Particular care should be taken when testing overcurrent functions that
the thermal rating of the current inputs is not exceeded.
2.2.1 Definite Time Overcurrent (50)
If DTL setting is small, gradually increase current until element operates.
If DTL is large apply 0.9x setting, check for no operation, apply 1.1x setting, check operation
Apply 2x setting current if possible and record operating time
Phase Dir. Is
(Amps)
DTL
(sec)
P.U. Current
Amps
Tol Operate Time
2 x Is
Tol
I
L1
(I
A
)
I
L2
(I
B
)
I
L3
(I
C
)
Check correct indication, trip output, alarm contacts, waveform record.