Putting Into Service; On-Load Testing; Final Checks - Siemens 7SG11 Technical Manual

Apply a Delay Time, ideally the time required for the scheme. Take 3 timings and average the
values. The overall delay time should be the sum of the instantaneous operate time and the
DTL time. Record the times in Table 4.
Performing this test is all that is essentially required to prove that the relay is functioning
correctly. This is because the timing test also proves that the crystal oscillator, which clocks the
microprocessor, is running at the correct frequency.

4 Putting into service

After all of the tests have been performed satisfactorily the relay should be put into service as follows :
•
Remove all test connections and replace any external wiring, which may have been removed to allow
testing.
•
Replace all fuses and links.
•
It is important to check that the correct settings group is active, if more than one group has been
programmed.

4.1 On-load Testing

This test should only be performed if there are no restrictions on energising the system which is being
commissioned.
Energise the system and measure the secondary voltages. Compare these with the relay's measured
values which are displayed in the instruments display mode. The values should compare and be within
± 2%.
Look at the relay's primary voltage displays. These will be indicating the primary voltages which have
been scaled to the correct ratio of the line voltage transformers.
If the relay is a 2 pole version and has been configured as 2Ph-Ph connection, or a 3 pole version,
configured as 3Ph-Ph or 3Ph-N+NVD, then look at the V1 and V2 instruments displays. These will
prove that the system phasing is correct. For correct phasing and rated system volts the V1 instrument
should read full rated volts and the V2 instrument should read 0V.
If the relay versions are not configured as mentioned above, then test that the system volts are phased
correctly using a phase rotation meter.

4.2 Final Checks

• Remove any test leads and links which have been used during the on-load testing phase.
• In the CB Maintenance menu reset the Trip Counter if any trips have been registered.
• Reset any alarms and LED's.
• Replace the relay cover and secure.
If a password has been entered the relay will automatically log the user out after a time of 1 hour has
.
elapsed
©2011 Siemens Protection Devices Limited
7SG11 Argus 8 Commissioning
Chapter 7 Page 8 of 12