Primary Tests - Siemens Reyrolle 7SR5 Operating Manual

6.4

Primary Tests

A requirement for the primary test is that prior tests (see
been completed successfully.
Primary tests may be done only by qualified personnel who are familiar with the commissioning of protection
systems, with the operation of the system, and with safety regulations and provisions (switching, earthing,
etc.).
Primary injection tests are essential to check the CT ratio and polarity of the CT transformer connections as
well as the secondary wiring to the device terminals.
Switching operations also have to be performed for complete commissioning of the protection system.
i
i
NOTE
For all high current if the current transformers associated with the protection are located in power trans-
former bushings it may not be possible to apply test connections between the current transformer and the
power transformer windings. Primary injection is needed, however, to verify the polarity of the CTs. In
these circumstances primary current must be injected through the associated power transformer winding.
It may be necessary to short circuit another winding in order to allow current to flow. During these primary
injection tests the injected current is likely to be small due to the impedance of the transformer and limita-
tions of test equipment.
!
DANGER
Danger due to hazardous voltages during the operation of electric devices
Noncompliance with the safety notes will result in death or severe injuries.
Only electrically qualified personnel may work on these devices. The electrically qualified personnel
²
must be thoroughly familiar with pertinent safety regulations and precautionary measures as well as
the warnings in this manual.
Reyrolle 7SR5, Operating, Manual
C53000-B7040-C013-1, Edition 05.2021
6.2 Initial Startup and 6.3 Secondary
Commissioning
6.4 Primary Tests
Tests) have
87