7PG2113/4/5/6 Commissioning & Maintenance
©2012 Siemens Protection Devices Limited
Chapter 6 Page 41 of 77
2.9
Sensitive Earth fault (67/50S,67/51S)
Figure 2.9-1 Sensitive Earth Fault
Voltage Inputs:
V
L1
(V
A
), V
L2
(V
B
), V
L3
(V
C
) for directional elements
Current Inputs:
I
4
(I
SEF
)
Disable:
64H,
50CBF,
79
Map Pickup LED:
51SEF-n/50SEF-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, Sensitive EF & Restricted EF protections can be
Enabled/Disabled individually or as groups in the ‘Function Config’ menu.
Sensitive EF elements can be separated from Derived EF by secondary injection of current through the I
4
input
circuit only.
If any of these elements are defined as directional the correct voltage phase direction will be required to produce
an operation of those elements.