Megger IDAX 300, Руководство пользователя

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IDAX 300/322/350 ZP-AG03E AG033586EE
4 IDAX 5 SOFTWARE
Analysis
In a Moisture Test; when DFR sweep passes 1 Hz, the
first automatic analysis is performed and preliminary
results are presented in the “Analysis results” section.
After the test is completed (last frequency point
measured) the final analysis results are displayed:
▪
Measured capacitance and %DF
▪
Calculated dissipation factor at 20°C reference
temperature using ITC (individual temperature
correction)
▪
Moisture content in the solid insulation
▪
Oil conductivity at 25°C reference temperature
using ITC
Insulation assessment guidelines
Assessment of %DF/%PF @ 20°C is based on
accumulated experience and generally in agreement
with IEEE C57.152 and CIGRE TB 445. Moisture
content analysis reflects:
▪
Manufacturers requirement for new large
transformers to be under 0.5% and somewhat
higher (<1.0%) for new distribution transformers
▪
Owners predisposition to allow no more than 3%
for aged and heavy loaded large transformers and
3.5% for smaller less heavy loaded transformers
▪
Recommendations in IEC 60422 and IEEE C57.106
Assessment of liquid conductivity is also based on
experience as well as on IEC 60422 and IEEE C57.106
due to lack of more specific standards.
The limits for DF/Moisture/Liquid conductivity
assessments are adjustable.
Insulation geometry
In Moisture Test, limits for insulation geometry
matching are based on the selected test object. For
power transformer, limits are pending if the design is
shell or core type, as described in the application note
“Dielectric Frequency Response (DFR) Measurement
and Analysis Settings (IDAX/MODS)”. The resulting
geometry model parameters can be viewed in the
“Analysis” window by pressing the “Analysis” button
in the right-hand side of the main window.
Disconnect/re-connect
It is possible to disconnect the computer and let
the IDAX unit run standalone by pressing the “Run
Standalone” button and then disconnect your
computer. The data will automatically be stored in the
IDAX instrument’s internal memory and uploaded to
the IDAX 5 when it is re-connected (you may even
close IDAX 5 software and turn off your computer but
if you re-connect using a different computer, you will
only get test data which does not include general e.g.
Nameplate data).