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Chapter 6) 7SR17 Commissioning and Maintenance Guide
the normally active group. This Test group may also be used for functional testing where it is necessary to disable
or change settings to facilitate testing.
When using settings groups it is important to remember that the relay need not necessarily be operating
according to the settings that are currently being displayed. There is an 'active settings group' on which the relay
operates and an 'edit/view settings group' which is visible on the display and which can be altered. This allows the
settings in one group to be altered from the relay fascia while the protection continues to operate on a different
unaffected group. The 'Active Settings Group' and the 'Edit Settings Group' are selected in the 'System
Configuration Menu'.
The currently Active Group and the group currently Viewed are shown at the top of the display in the Settings
display screen. If the View Group is not shown at the top of the display, this indicates that the setting is common
to all groups. CT/VT ratio, I/O mapping and other settings which are directly related to hardware are common to
all groups.
If the relay is allowed to trip during testing then the instruments display will be interrupted and replaced by the
'Trip Alert' screen which displays fault data information. If this normal operation interferes with testing then this
function can be temporarily disabled for the duration of testing by use of the Trip Alert Enabled/Disabled setting in
the System Config Menu.
After applying a settings change to the relay, which may involve a change to the indication and output contacts,
the TEST/RESET key should be pressed to ensure any existing indication and output is correctly cleared.
1.2.7
Relay Functionality
To aid relay testing the relay functionality is illustrated in logic diagram form – see chapter 1 'Description of
Operation'.
©2014 Siemens Protection Devices Limited
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