3.2 Checking Connections
259
7UM61 Manual
C53000-G1176-C127-3
Test Switch
Check the functions of all test switches that are installed for the purposes of secondary
testing and isolation of the device. Of particular importance are “test switches ” in
current transformer circuits. Be sure these switches short-circuit the current transform-
ers when they are in the test mode.
3.2.3
Checking System Incorporation
General Informa-
tion
WARNING!
Warning of hazardous voltages
Nonobservance of the following measures can result in fatality, personal injury or sub-
stantial material damage.
Only qualified people who are familiar with and observe the safety procedures and
precautionary measures shall perform the inspection steps.
With this check of the protection, the correctness incorporation into the power system
is tested and ensured.
Checking of protection parametrization (allocations and settings) in accordance with
the power system requirements, is an important test step here.
The interface-wide incorporation check in the power system results on the one hand
in testing of cubicle wiring and drawing records in accordance with functionality, and
on the other hand the correctness of cabling between transducer or transformer and
protection device.
The check of the protection device functions with regard to accuracy of pickup values
and the characteristic itself should not be part of this check, since this is done by the
works test.
Auxiliary Voltage
Supply
Testing of voltage amplitude and polarity at the input terminals
Note
If a redundant supply is used, there must be a permanent, i.e. uninterruptible connec-
tion between the minus polarity connectors of system 1 and system 2 of the DC
voltage supply (no switching device, no fuse), because otherwise there is a risk of
voltage doubling in case of a double earth fault.
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