Chapter 2) 7XG3124 Application Guide
©2014 Siemens Protection Devices Limited
Chapter 2 Page 13 of 42
The proposed scheme is as follows:
The scheme comprises of RA30 sensors connected to a RA24 Arc Fault Monitor, providing ARC Fault
coverage of the colored protection zones.
The RA24 provides the SARC Logical Node for the operation of Arc Fault Sensors.
The 7SR22 Overcurrent relay subscribes to SARC Goose messages and initiates the required protection
tripping via an Overcurrent Check.
Tripping in this case will be carried out by hardwiring to respective circuit breakers and using binary outputs
from the 7SR22 IED but could also be implemented via Goose by another subscribing IED.
Flexible tripping logic may be implemented in the 7SR22 according to specific application requirements and
may also accommodate different operating arrangements in more complex applications.
Upstream Trip:
Hardwired or
Goose
SARC Goose
Downstream Trip
Hardwired or
Goose
Sensor connections to RA24
RA24
TR1
7SR22
Figure 8: RA24 Sample Protection Scheme