Figure 3-7 Logic Diagram: Derived Time Delayed Earth Fault Protection - Siemens 7SR10 Argus Series Manual

51N-n Inrush
Action
Off
Inhibit
&
81HBL2
AUTORECLOSE
79 P/F Inst Trips
= 51N-n
&
79 P/F Prot'n Trip n
= Delayed
51N-n Dir.
Control
Non-Dir
Forward
Reverse
67N Fwd.
67N Rev.
Figure 3-7
©2018 Siemens Protection Devices Limited
51N-n Element
Disabled
Enabled
&
Inhibit 50N-n
51N-n Dir En
IL1
IL2
IL3
51N-n VTS Action
Off
Non Dir
Inhibit
VT Fail
≥1
&
&
Logic Diagram: Derived Time Delayed Earth Fault Protection
51N-n Setting
51N-n Charact
51N-n Time Mult
51N-n Delay (DTL)
51N-n Min Operate Time
51N-n Follower DTL
51N-n Reset
c
Pickup
I
N
trip
If directional elements are not present this block is
omitted and the '51N-n Dir En' signal is set TRUE.
& &
&
7SR10 Description of Operation
General Pickup
51N-n
≥1
51N-n Dir En
Chapter 1 Page 33 of 77