Chapter 5 - 7SR45 Installation Guide
© 2018 Siemens Protection Devices Limited
Chapter 5 Page 10 of 12
Relay
Applications
Description
Connections
7SR45 Self
Powered
Relay for
Distribution
Transformer
Application
1. CT circuits shown are connected
to 1 A or 5 A of 7SR45 Argus
relay.
2. CT and Earth connections are
typical only.
3. Measures the phase current and
earth current of the Primary CT
only.
4. Application shows the use of
50/51/50N/51N/ 50LC/50G/51G
protection functions.
5. Remote trip via binary input is
possible.
IL1 IL2 IL3
24 V DC, 0.1 Ws
IL1
IL2
IL3
IL4
7SR45
PO
+ ve
- ve
IL1 IL2 IL3 N
Distribution
Transformer
Figure 1-15
7SR45 Self Powered Relay for Distribution Transformer Application