Section 1: Common Functions - Siemens Argus 7SR21 Technical Manual

Section 1: Common Functions

1.1 Multiple Settings Groups
Alternate settings groups can be used to reconfigure the relay during significant changes to system conditions
e.g.
Primary plant switching in/out.
Summer/winter or day/night settings.
switchable earthing connections.
Loss of Grid connection (see below)
Industrial system draws power from grid
system during normal operation
Relays normally use settings group 1
On loss of mains:
Local generation switched in.
Non essential loads tripped
Relays on essential circuits switched to
settings group 2 to reflect new load and
fault currents
© 2013 Siemens Protection Devices Limited
Start
generators
Local
Generation
Non-essential
loads
Figure 1.1-1 Example Use of Alternative Settings Groups
7SR210 & 7SR220 Applications Guide
Trip non-essential loads
Select alternate
settings group
RADIAL SUBSTATION
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