Section 2: Additional Functions
2.1
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
Figure 2.1-1 Example Use of Alternative Settings Groups
The Current Differential protection has fixed settings which cannot be adjusted by settings groups.
©2010 Siemens Protection Devices Limited
Start
generators
Local
Generation
Non-essential
loads
7PG2113/4/5/6 Solkor Applications Guide
Trip non-essential loads
Select alternate
settings group
RADIAL SUBSTATION
Chapter 7 Page 14 of 49