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7SR157 Technical Manual
1.2.4
Use of PC to facilitate testing
The functions of Reydisp Evolution (see Section 2: Settings and Instruments) can be used during the
commissioning tests to assist with test procedures or to provide documentation recording the test and test
parameters. One method is to clear both the waveform and event records before each test is started. Then, after
the test upload from the relay, the settings, events and waveform files generated can then be saved off to retain a
comprehensive record of that test.
Relay settings files can be prepared on the PC (offline) or on the relay before testing commences. These settings
should be saved for reference and compared with the settings at the end of testing. This is to check that errors
have not been introduced during testing and that any temporary changes to settings to suit the test process are
returned to the required service state.
A copy of the Relay Settings as a Rich Text Format (.rtf) file, suitable for printing or for record purposes can be
produced from Reydisp as follows: from the File menu select Save As, change the file type to Export
Default/Actual Setting (.RTF) and input a suitable filename.
When testing is completed, the event and waveform records should be cleared and the settings file checked to
ensure that the required in-service settings are being applied.
1.2.5
Precautions
Before electrical testing commences the equipment should be isolated from the voltage transformers. The tripping
and alarm circuits should also be isolated where practical. The provision and use of secondary injection test
sockets on the panel simplifies the isolation and test procedure.
Ensure that the correct auxiliary supply voltage and polarity is applied. See the relevant scheme diagrams for the
relay connections.
1.2.6
Applying Settings
The relay settings for the particular application should be applied before any secondary testing occurs. If they are
not available then the relay has default settings that can be used for pre-commissioning tests. See the Relay
Settings section of this manual for the default settings.
Note that the tripping and alarm contacts for any function must be programmed correctly before any scheme tests
are carried out.
The relay features multiple settings groups, of which only one is active at a time. In applications where more than
one settings group is to be used it may be necessary to test the relay in more than one configuration.
Note: one group may be used as a Test group to hold test-only settings that can be used for regular maintenance
testing. This eliminates the need for the Test Engineer to interfere with the actual in-service settings in 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.
1.3
Tests
1.3.1
Inspection
Ensure that all connections are tight and correct to the relay wiring diagram and the scheme diagram. Record any
deviations. Check that the relay is correctly programmed and that it is fully inserted into the case. Refer to Section
2: Settings and Instruments for information on programming the relay.
©2016 Siemens Protection Devices Limited
Chapter 6 - Page 4 of 14
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