Siemens Argus 7SR21 - Page 569

7SR210 & 7SR220 Commissioning & Maintenance Guide
© 2013 Siemens Protection Devices Limited Page 57 of 82
2.10.9 Under/Over Frequency (81)
7SR22
46
BC
46
NPS
(x2)
37
(x2)
49
50
BF
V
L1
(V
A
)
V
L2
(V
B
)
V
L3
(V
C
)
V
4
(V
X
)
I
L1
(I
A
)
81
HBL
2
37
(x2)
49
50
BF
I
L2
(I
B
)
81
HBL
2
37
(x2)
49
50
BF
I
L3
(I
C
)
81
HBL
2
60
CTS
I
4
(I
G
)
I
5
(I
SEF
)
74
TCS
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)
67/
50S
(x4)
67/
51S
(x4)
64
H
27
59
27
59
(x4)
27
59
(x4)
27
59
(x4)
47
(x2)
81
(x6)
79
Optional
59N
(x2)
Note:
Example shows
Voltage Config =
Van, Vbn, Vcn
81
HBL
2N
81
HBL
2G
60
CTS-
I
60
VTS
51V
51V
51V
37G
(x2)
37S
(x2)
51c
51c
51c
Figure 2.10-5 Under/Over Frequency
Voltage Inputs: V
L1
(V
A
), V
L2
(V
B
), V
L3
(V
C
)
Current Inputs: n/a apply zero current to stabilize other functions.
Disable:
Map Pickup LED: 81-n - Self Reset.
This function can be tested by application of 1P or 3P voltage. For Over-frequency, the elements with the highest
setting should be tested first and for Under-frequency the elements with the lowest settings should be tested first.
The elements with other settings can then be tested without need to disable the elements already tested. Note
that the relay is designed to track the gradual changes in power system frequency and that sudden step changes
in frequency during testing do not reflect normal system operation. Normal ‘instantaneous’ operation of the
frequency element is 140 ms to 175 ms in line with the Performance Specification. Application of sudden step
changes to frequency can add additional delay which can produce misleading test results.
Gradually increase/decrease applied voltage frequency until 81-n operation occurs. Elements set for more
extreme frequency fluctuation should be tested first with lesser elements disabled.