Vertical bands in photo are an artifact
of camera exposure and screen update, the
screen looks great to the eye
The CTMP-2006 offers two ranges, 0 - 200VAC
and 0 - 1000VAC, that facilitate saturation testing
of current transformers. In this mode the unit displays
exciting current and voltage. A real time graph is
plotted on the screen during performance of the test allowing
observance of the knee. A distortion measurement identifies
the spike in the exciting current waveform as the
core saturates and flags this point by displaying the
word SAT ! under the current reading. The CTMP eliminates
the need for plotting a large number of data points to
determine saturation. Simply record the current and voltage
at which the knee "breaks" and the word SAT! appears and
you have accurately completed this test.
Data may be transmitted to a PC via serial port
for easy creation of a data sheet. The firmware of
the CTMP 2006 has been modified to work with an
available freeware RS-232 to keyboard wedge and will now
write ratio and saturation data directly into the correct cell of a supplied
Excel template and graph the saturation characteristic
as you test.
Click here to download template
for 0 to 200V.
Click here to download template
for 0 to 1000V.
The CTMP with its robust
400VA output transformer is an excellent tool for CT
saturation testing. The precise metering system measures
output voltage to 2000VAC and current to 2AAC, accuracy is
0.4%.
You may custom configure the saturation test capacity of
your CTMP-2006. Outputs up to 1500VAC and 700VA are available
on special order. Optional current metering ranges of 0-5
and 0-10 AMPS may also be ordered. Call the factory to dicuss
any special requirements, at Calvada Technologies we
build your test set for your needs !
I would like to
say however, that, in my opinion, 1000 volts is enough
and I
would not apply more than 1000V to a CT secondary without
first consulting the manufacturer of the CT. It is possible
that the CT winding and connecting leads are insulated
for only 600V. The exciting current of a CT that saturates at
a very high voltage can be recorded at 1000V and this data
compared to that obtained by the manufacturer and
other units of the same type. A compliance
voltage requirement may be calculated using the secondary
current at the maximum anticipated fault and the measured
burden of the relay circuit. This voltage is usually
below 100 and represents the highest value that the
CT would see in service. A CT that does not saturate at
a high multiple of the maximum anticipated burden voltage
can certainly be deemed
suitable for its application without "finding the knee".