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3 Mounting and Commissioning
A plausibility check of the analog-digital converter with the operational measured
values is sufficient since the subsequent processing of the measured values is numer-
ical and thus internal failures of protection functions can be ruled out.
For any secondary checks to be carried out, where possible three-phase test equip-
ment with currents and voltages is recommended (e.g. Omicron CMC 56 for manual
and automatic checking). The phase angle between currents and voltages should be
continuously adjustable.
The measurement accuracy to be achieved depends on the electrical data of the test
sources used. The accuracies specified in the technical specifications can be expect-
ed only if the reference conditions in accordance with VDE 0435/Part 303 or IEC 60
255 are adhered to, and precision measurement instruments are used.
Tests can be done with the current setting values or with the preset values.
If unsymmetrical currents and voltages occur during the tests it is likely that the asym-
metry monitoring will frequently pickup. This is of no concern because the condition of
steady-state measured values is monitored which, under normal operating conditions,
are symmetrical; under short circuit conditions these monitorings are not effective.
Note
If during dynamic testing, measured values are connected from or reduced to zero, a
sufficiently high value should be present at least one other measuring circuit (in
general a voltage), to permit frequency adaptation.
Measured values in earth paths of voltage or current (I
ning frequency. To check them a sufficiently high value measured value should be
present in one of the phases.
Wiring
Important is in particular checking of the correct wiring and allocation of all interfaces
of the device. The test function described in section 3.3 for checking the binary inputs
and outputs is a help here.
The analog inputs can be checked using plausibility checks as described under "Sec-
ondary Test".
Function Check
The only functional test required for protective relays is a plausibility check of the op-
erational measured values by means of some secondary test equipment; this is to
ensure that no damage has occurred during transit (see also side title "Secondary
Testing").
Undervoltage Pro-
Note: If in the device undervoltage protection function is configured and activated, the
tection
following must be considered: Special measures have been taken to ensure that the
device does not pick up immediately after applying the auxiliary power supply, as a
result of the absent measured voltage. However, the device does pick up as soon as
operating state 1 (measured values exist) has been attained.
LEDs
After tests where the displays appear on the LEDs, these should be reset in order that
they present information only on the currently executed test. This should be done at
least once each using the reset button on the front panel and via the binary input for
remote reset (if allocated). Observe that an independent reset occurs also on the
arrival of a new fault and that setting of new indications can be optionally made depen-
dent on the pickup or a trip command (parameter 7110 FltDisp.LED/LCD).
258
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) can not adapt the scan-
EE
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7UM61 Manual
C53000-G1176-C127-3
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