XT2640 Operating Manual
13 July 2016
Page 19 of 187
8.5
TYPICAL
TRIPLE
VPA
APPLICATIONS
Examples of triple VPA applications as shown in the diagram below include –
Emergency Lighting Ballasts (most types)
Standby or Backup Power Supplies (AC or DC)
There are also other triple VPA configurations which are not shown here. As example –
If a facility has a backup or PV source of power, an internal power distribution, and also access to a network supply then
three VPAs can be used, one measuring each of these. In this case you should note that the XT2640 can also separately
integrate the bought and sold power for the network power source.
Each VPA has the same capabilities and are independently configured as for single VPA applications (except only a single
oscilloscope in one VPA is allowed).
Each VPA can be configured as N x 1
ø
, 2
ø
3w, 3
ø
3w(2ch), 3
ø
3w(3ch) or 3
ø
4w limited by the total number of channels
installed.
Efficiency and power loss can be measured, overall and for each intermediate stage.
For the example shown above, the total charge and discharge AHr for the battery can be measured.
The VPAs may be configured as either –
Totally independent and having totally different frequency content signals to each other.
Or, have totally different frequency content signals but make measurements over times which are synchronized
to each other.
Or, have the same frequency content signals and make measurements over exactly the same periods of time (the
oscilloscope captures the signals in both VPAs in this case).
8.6
MECHANICAL
(MOTOR/GENERATOR)
APPLICATIONS
If a MT type channel is installed and configured in the CH4 location then it can be used for mechanical measurements in addition to
the previously described electrical measurements performed in VPA1 to VPA3. The measurement of mechanical data can be made
independently of electrical measurements, or synchronized to a VPA, or all VPAs and the motor/generator measurements may all be
synchronized together.
See section 12.4.3 for configuring the XT2640 for motor/generator measurements.
XT2640
POWER
SOURCE
AC
to
DC
VPA
1 to 4
channels
LOAD
VPA
1 to 4
channels
DC
to
AC
BATTERY
VPA
1 to 4
channels
