Siemens 7SR18 Solkor - Derived Earth Fault (50 N, 51 N)

7SR18 Commissioning & Maintenance Guide
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of
3.5 DERIVED EARTH FAULT (50N, 51N)
Figure 3.5-1 Derived Earth Fault
Current Inputs: I
L1
(I
A
), I
L2
(I
B
), I
L3
(I
C
)
Disable: 37, 46, 49, 50CBF, 60CTS-I, 46BC
Map Pickup LED: 51N-n/50N-n - Self Reset
Other protection functions may overlap with these functions during testing; it may be useful to disable some
functions to avoid ambiguity. Derived EF & Measured EF protections can be Enabled/Disabled individually or as
groups in the ‘Function Config’ menu.
Derived EF elements can be separated from Measured EF by arrangement of the secondary injection circuit by
shorting/disconnecting I
4
Input.