Siemens Argus 7SR21 Technical Manual page 556

7SR210 & 7SR220 Commissioning & Maintenance Guide
2.8 Undercurrent. (37)
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:
If two Undercurrent 37 elements are used with different settings, it is convenient to test the element with the
lowest setting first. The higher setting element can then be tested without interference from the other element.
Apply 3P balanced current at a level above the Undercurrent 37-n setting until the element resets.
If DTL setting is small, gradually reduce any each phase current in turn until element operates.
If DTL is large apply 1.1x setting, check for no operation, apply 0.9x setting, and check operation
Testing of this element phase by phase may cause inadvertent operation of the 46 NPS Overcurrent elements.
Apply 0.5x setting current and record operating time.
Page 44 of 82
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 2.8-1 Undercurrent
n/a
I (I ), I (I ), I
L1 A L2 B L3
51N, 51G, 46, 60CTS, 46BC
37-n - Self Reset
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
(I ),
C
© 2013 Siemens Protection Devices Limited
81
51c HBL
2
81
51c HBL
2
81
51c HBL
2
81
HBL
2N
37G
(x2)
37S
(x2)