Instantaneous Measured Earth Fault Protection (50G); Figure 3-5 Logic Diagram: Instantaneous Measured Earth-Fault Element - Siemens 7SR45 Argus User Manual

3.5

Instantaneous Measured Earth Fault Protection (50G)

The earth current is measured directly via a dedicated current analogue input, IL4/I
Two instantaneous measured earth fault elements are provided in the 7SR45 Argus Relay.
50G-1, 50G-2
Each instantaneous element has independent settings for pick-up current 50G-n Setting and a definite time delay
50G-n Delay.
Operation of the instantaneous measured earth fault elements can be inhibited by assigning binary inputs.
Inhibit 50G-n
Gn 50G- n Element
Disabled
Enabled
Inhibit 50 G- n
51G/50G Measurement
I
G
Table 3-7
Parameters Description
Gn 50G-n
50G-n Block
Element
Gn 50G-n Setting Pick-up current
Gn 50G-n Delay Delay time
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A binary input
&
Gn 50G- n Setting
c
>
Figure 3-5 Logic Diagram: Instantaneous Measured Earth-fault Element
Instantaneous Measured Earth Fault Protection (50G-n)
Default Value
Disabled
0.2xI
0
Chapter 1 - 7SR45 Description of Operation
E
Gn 50 G - n Delay
Min Max
- -
1xI 20xI
n n
0 s < 20 s
≥ 20 s < 100 s
≥ 100 s 600 s
.
General Pickup
50 G - n
Step Change
-
0.1
n
0.01
0.1
1
Chapter 1 Page 30 of 48