2.7
Derived Earth Fault (67/50N, 67/51N)
Voltage Inputs:
Current Inputs:
Disable:
Map Pickup LED:
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 Sensitive EF & Restricted EF protections can be
Enabled/Disabled individually or as groups in the 'Function Config' menu.
Derived EF elements can be separated from Measured/Sensitive EF by arrangement of the secondary injection
circuit by shorting/disconnecting I
If any of these elements are defined as directional the correct voltage phase direction will be required to produce
an operation of those elements.
©2012 Siemens Protection Devices Limited
Figure 2.7-1 Derived Earth Fault
V
(V
), V
(V
), V
(V
L1
A
L2
B
L3
I
(I
), I
(I
), I
(I
)
L1
A
L2
B
L3
C
37, 46, 49, 60CTS, 50CBF, 60CTS, 46BC, 79
51N-n/50N-n - Self Reset
Input.
4
7PG2113/4/5/6 Commissioning & Maintenance
)
C
Chapter 6 Page 33 of 77