Atec Megger-mct1605 - Manual (Page 2)

MCT1605
Multi-Tap Automatic Current Transformer Saturation,
Ratio and Polarity Test Set
Ratio Test
Ratio testing is performed by comparing a voltage applied
to the secondary winding to the resulting voltage produced
on the primary winding. For example, if 1 volt per turn is
applied to the secondary winding, the voltage present on
the primary winding would be 1 volt. More specifically, if
120 volts were applied to the secondary of a 600/5 current
transformer (120:1 ratio), 1 volt would be present on the
primary winding. This test is performed automatically
during a CT saturation test or manually with the output
control knob and metering display. The MCT1605 will
also provide the operator with a direct reading ratio, thus
removing the need to calculate CT ratio manually.
Polarity Test
Polarity of the current transformer under test is indicated to
the operator by a simple “Correct” or “Incorrect” indication
on the display accompanied by the measured phase angle.
Demagnetization
Normal operating conditions and typical winding resistance
measurements can cause a CT to become magnetized. The
MCT1605 has the ability to automatically demagnetize the
CT under test. This automatic demagnetization routine is
useful to ensure that the CT Saturation test yield correct
results. Prior to testing demagnification is recommended
per ANSI C57.13.1.
CT Burden Measurement
In addition to performing any required CT test, the
MCT1605 has the ability to measure the actual connected
Burden. When the actual measured burden is compared
against the calculated burden, the user confirms that the CT
will operate with published rating.
Insulation Resistance Test
In order to ensure that the CT secondary wiring is properly
insulated, the MCT1605 system includes a 500/1000V
insulation resistance test system. This test ensures that the
CT secondary winding and secondary wiring is properly
insulated per ANSI C57.13.1.
The MCT1605 will also automatically switch the test leads
to perform all required insulation test. These test include
H-L, H-G, L-G
Note: Disconnect all electronic loads before performing this
test.
Winding Resistance
Measuring the DC resistance of transformer windings
will aid in identifying problems such as shorted or open
windings as well as loose connections.
Data Storage and Printing
The MCT1605 test system not only permits accurate and
automated CT testing, but also catalogues and stores
test results within the instrument for simple retrieval by
software at a later date. All catalogued test results can be
uploaded to Megger’s PowerDB
TM Lite for report generation
and saturation curve plotting on a computer. PowerDB
Lite also has the ability to operate the MCT1605 with
no operator intervention, thus providing a completely
computer controlled automated test system.
With a manual voltage
output control knob, the
user is able to perform
any test required manually
if only a spot check is
required.
Complete report generation with PowerDb Lite
The operator also has the option to print any catalogued
test results immediately using an optional printer, providing
hard copy of test reports immediately upon CT test
completion.
Onboard memory allows complete test results and data to
be stored in one complete file, permitting easy access to
quick construction of reports such as saturation curve with
knee point. The MCT1605 test file is saved in a Microsoft
XML format, thus the data is available to any application
that will accept an XML format.