Checking The Instrument Transformer Connections For More Than Two Ends - Siemens siprotec 7SD5 User Manual

3 Mounting and Commissioning
Figure 3-33 Differential and restraint currents — example for plausible currents
3.3.9

Checking the Instrument Transformer Connections for More than Two Ends

If there are more than two ends, all tests according to the above Section „Checking
the Instrument Transformer Connections for More than Two Ends"— as far as they are
applicable in this case — have to be repeated for other current paths in such a way
that all ends of the object to be protected have been included in the current flow test
at least once. It is not necessary to test every possible current path.
At the ends not involved in a test the circuit breakers are to remain open. Also pay at-
tention to all safety notes — especially the DANGER warning in the above Section
„Checking the Instrument Transformer Connections for More than Two Ends".
The circuit breakers are reopened after the last test.
In the event that parameters were modified for the tests, they finally have to be set to
the values necessary for operation.
506
7SD5 Manual
C53000-G1176-C169-1