Instantaneous Overcurrent Protection (50); Figure 3-1 Logic Diagram: Instantaneous Overcurrent Element; Section 3: Protection Functions (50, 51, 50N, 51N, 50G, 51G, 50Lc) - Siemens 7SR45 Argus User Manual

Section 3: Protection Functions (50, 51, 50N, 51N, 50G,
51G, 50LC)
3.1

Instantaneous Overcurrent Protection (50)

Two Instantaneous overcurrent elements are provided in the 7SR45 Argus Relay.
50-1, 50-2
Each instantaneous element (50-n) has independent settings. 50-n Setting for pick-up current and
50-n Delay definite time delay.
Operation of the instantaneous overcurrent elements can be inhibited by assigning binary inputs.
Inhibit 50-n
Gn 50-n
Enabled
Disabled
&
Inhibit 50-n
Gn 50/51
Measurement
IL1
IL2
IL3
Figure 3-1
Table 3-1
Parameters Description
Gn 50-n Element 50-n Block
Gn 50-n Setting Pick-up current
Gn 50-n Delay Delay time
NOTE:
In a single-phase condition, it is recommended to use 50-n Setting 0.3xIn or higher.
©2018 Siemens Protection Devices Limited
A binary input.
Gn 50-n Setting
c
>
>
>
Logic Diagram: Instantaneous Overcurrent Element
Instantaneous Overcurrent Protection (50-n)
Default Value
Disabled
1
0
Chapter 1 - 7SR45 Description of Operation
≥1
Gn 50-n Delay
≥1
Min Max Step Change
- - -
0.2xI 20xI 0.1
n n
0 s < 20 s 0.01
≥ 20 s < 100 s 0.1
≥ 100 s 600 s 1
Chapter 1 Page 24 of 48
General Pickup
50-n