Pole Diff + Ef' Operation; Figure 3-6 Logic Diagram: '3 Pole Diff + Ef' Protection - Siemens 7SR23 DAD Manual

3.4.2 '3 Pole Diff + EF' Operation

The relay can be used to provide both 3 phase differential and earth fault protections using the SYSTEM CONFIG
> Relay Config > 3 Pole Diff + EF setting.
When configured in this way the relay uses the 87/50-n and the 50G-n elements. These elements operate
independently of each other, an output may be given only when both are operated – see Figure 3-6 below.
When 87/50-n Trip Check Logic is Enabled outputs are available when any two phases operate (i.e. 87/50-n
phase-phase check) or when an 87/50 element operates coincidentally with the 50G element (phase-earth
check).
For detailed information on differential and earth fault functions refer to sections 3.1and 3.2.
87/50-n
Disabled
Enabled
Zone Switch Out
Inhibit 87/50-n
User Inhibit 87/50-n
87/50-n CT50
Inhibit 87/50A-n
Inhibit
Disabled CT50A
Enabled
Inhibit 87/50B-n
CT50B
IA
IB
IC
Inhibit 87/50C-n
CT50C
87/50-n Trip
Check Logic
Disabled
Enabled
50G-n
Disabled
Enabled
EF IN (Control)
&
User Inhibit 50G-n
Inhibit 50G-n
IG
50G-n
Measurement
Fundamental
RMS
©2013 Siemens Protection Devices Limited
&
87/50-n Setting
Enable
Blk
1
&
Blk
1
&
Blk
1
&
50G-n Setting
Enable
Pickup
En
Operate
Notes
For details of data communications points refer to Technical Manual, Chapter 4 (Data Communications).
For details of user logic inputs and outputs refer to the relevant Reydisp Manager template.
Figure 3-6 Logic Diagram: '3 Pole Diff + EF' Protection
Chapter 1) 7SR23 DAD Description Of Operation
3
87/ 87/
CT50
50-1 50-2
1
74
50G
TCS
(x2)
x12
1
87/50-n Delay
Pickup
Operate
Pickup
Operate
Pickup
Operate
50G-n Delay
7SR23
DAD
General Pickup
87/50-n
1
87/50A-n
87/50AB-n
&
& 87/50AG-n
87/50B-n
& 87/50BC-n
& 87/50BG-n
87/50C-n
& 87/50CA-n
87/50CG-n
&
General Pickup
50G-n
Chapter 1 Page 21 of 36