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6 - 28
Siemens AG ⋅ January 1999
6.6.1 General
Before commissioning, the preparations for putting
the device into service as stipulated in chapter 5 must
be completed.
Warning
During service, some parts of electrical
devices are inevitably under dangerous
voltage. This may cause serious persoĆ
nal injury or material damage to equipĆ
ment if not handled professionally.
Only qualified personnel should work on
this device. This personnel must be faĆ
miliar with the pertinent safety regulaĆ
tions and the warnings in this manual.
Above all it should be observed:
D The device must be earthed at the
PE terminal before making any conĆ
nections.
D Dangerous voltages may occur in all
circuit parts connected with the
power supply and with the measuĆ
ring and test circuits.
D Dangerous voltages may still exist in
the device even after it has been diĆ
sconnected from the supply voltage
(charged capacitors).
D The permissible threshold values
specified under Technical data may
not be exceeded even during service
testing and commissioning.
When testing the device with secondary test equipĆ
ment, make sure that no other signal sources are
connected and the trip commands to the circuit-breaĆ
kers are interrupted.
Danger
The secondary connections of the
current transformers must be short-
circuited before the CT secondary
connecting cables to the device can
be disconnected!
If there is a test switch which automatiĆ
cally short circuits the current transforĆ
mer secondary connection, it is suffiĆ
cient to turn this to the "Test" position
providing that this CT short-circuit has
been tested beforehand (section 5.2.4).
It is recommended to test the device with the current
settings applied. If these are not (yet) available, the
default values should be used for testing. The
following description of the test sequences assumes
that the default settings are being used.
A symmetrical power source with individually controlĆ
lable currents is assumed for the function test. A sinĆ
gle-phase test current source is sufficient for the pick
up test.
i
Note
The measuring accuracy which can be
achieved depends on the electrical data
of the test sources used. The accuraĆ
cies specified in the technical data can
only be expected if there is compliance
with the reference conditions according
to VDE 0435/part 303 or IEC 60255,
and use of precision measuring instruĆ
ments. Tests with secondary test equipĆ
ment are therefore generally considered
as pure function tests.
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