XT2640 Operating Manual
13 July 2016
Page 111 of 187
20.4.5
TESTING
THE
LOAD
CURRENT
MODULATION
MEETS
REQUIREMENTS
The XT2640 may be used to confirm that the load current modulation is as required.
Note:
The bandwidth of the measurement may have a severe impact on the results obtained. You may wish to alter the MEAS
CONFIG ‐ BANDWIDTH setting while performing these tests to a lower value (e.g. 4kHz) to reduce the bandwidth of the
measurement.
It is required that this value be measured over many measurement periods of the XT2640 (so giving a result for low frequency
modulation) this is achieved by using the POWER DATA screen configured to show each channel, and INRUSH data.
To use this screen follow the procedure described below –
1.
Select the POWER DATA screen as shown above.
2.
Press the CLEAR button.
3.
Wait for the desired period of time (for example 1.5 seconds for DO160F 16.7.6).
4.
Press the area showing MEASUREMENTS RUNNING (this is called the MEASUREMENT INFO area in this manual). This holds all
measurements enabling you to view and record data without being concerned about the time taken to do so.
5.
Record the indicated current Apk and Vly data. The difference between these is the difference between the highest peak and the
lowest valley encountered during the period between pressing the CLEAR button and recording the result.
6.
Step 2 clears the data for all channels, so for a 3‐phase supply you do not need to repeat the entire procedure for each phase if
all phases are being modulated. Just repeat step 5, changing the selected channel to record the measurements for each phase.
7.
Do not forget to release the measurement hold after recording all phases.
20.4.6
TESTING
THE
LOAD
POWER
FACTOR
MEETS
REQUIREMENTS
The XT2640 may be used to confirm that the load power factor is as required.
This is performed by using the POWER DATA screen which should be selected to display the results for entire VPA (i.e. the entire
supply), showing the COUPLED data, and showing the full DETAILED information.
For all power factor data, if followed by an upwards pointing arrow the power factor is leading, otherwise it is lagging.
The primary data (shown in larger, gold colored text) for PF shows the overall power factor from the supply (for a 1‐phase supply
there is only a single phase).
The secondary data (shown in a smaller, white colored text) for power factor lists the power factor from each phase from the supply
(for a 1‐phase supply there is only a single phase).