AEMC PowerPad III 8336 User manual

1
Transient Capture on the
AEMC PowerPad III Model 8336
Transients are short-term current and voltage phenomena that occur in the system under
measurement. The process the AEMC PowerPad III Model 8336 uses for recording transients is
as follows:
•The instrument sampling rate is a constant
256 samples per cycle.
•When a transient search is started on the
instrument, each sample is compared to the
corresponding sample from the preceding
cycle.
•The transient threshold is the user-defined
amount of volts or amps for any datapoint to
differ from the corresponding datapoint
exactly 1 cycle earlier. The preceding cycle
defines the mid-point of the trigger envelope
and is used as reference.
•As soon as a sample is outside the envelope,
the triggering event occurs; the transient data
is then captured by the instrument.
•The cycle preceding the event and the three
following cycles are saved to memory.
The following explains how to configure, schedule,
and view a transient recording session on the Model
8336. These instructions assume you are using the
Model 8336 as a standalone instrument.
Note that you can also perform these tasks by connecting the instrument to a computer running
AEMC’s DataView software. For more information, see the PowerPad III Model 8336 User
Guide.

2
Transient Recording Configuration
1. With the instrument turned ON, press the button to display the Waveform Capture
screen.
2. Ensure Transient is highlighted, then press .
●If there are no transient detection sessions stored in the instrument, the Detection
Schedule screen appears.
●If there are recordings in the instrument, the Detection List screen isdisplayed. In this
case, press to display the Detection Schedule screen.
3. Press the function button under the icon to display the Voltage Thresholds
screen. At the top of the screen is the Threshold Set-up field. Options are:
●4V: The same voltage difference threshold applies to all phases and the neutral in the
electrical hook-up
●3V+VN: One threshold applies to the phases and one applies to neutral
●V1+V2+V3+V4: Each phase and neutral has its own assigned threshold
Depending on the electrical hook-up currently under measurement, not all these options
may be available.
4. The setting in this field determines which of the four fields below it (1, 2, 3, and N) are
editable:
●4V: a single field is active for 1, 2, 3, and N.
●3V+VN: one field is active for 1, 2, and 3; and another is active for N.
●V1+V2+V3+N: each field is active.
To edit a voltage threshold field, highlight it using the up and down arrow buttons, then
confirm the selection by pressing . Use the left and right arrows to select a digit, and the
up and down arrows to change it. You can also use these buttons to select units (V or kV).
Press to confirm the edited field.
5. Press the A button to display the Current Thresholds screen. This is similar to the Voltage
Threshold screen. You can select which thresholds apply to which phases, and specify the
value of the threshold (1mA through 9999kA). As with the voltage thresholds, not all these
options may apply to all electrical hook-up types.
Note that current transients typically occur frequently. We recommend performing a current
transient search only when looking for a specific type of transient. At other times, such as when
you are primarily interested in voltage transients, you can effectively disable current transient
searching by setting the threshold to its maximum value.

3
Scheduling Transient Detection
1. Press the button to display the Waveform Capture screen.
2. Ensure Transient is highlighted, then press .
●If there are no transient detection sessions stored in the instrument, the Detection
Schedule screen appears.
●If there are recordings in the instrument, the Detection List screen is displayed. In this
case, press the button to display the Detection Schedule screen.
3. This screen displays four input fields:
●Start defines the time and date when the recording starts. This must be later than the
current date and time.
●Stop specifies when the recording ends. This must be later than the start date and time.
●Transient Count defines the maximum number of transients that you want to capture
before stopping the session.
●Name allows you to name the test. This can be 8 characters long.
4. Use the arrow and buttons to highlight, select, and edit these fields.
5. Press the button to write the settings to the instrument and start the session.
6. If not enough memory is available, an error message appears informing you of this.
Otherwise, the transient detection session will begin at the scheduled start time and date.
If a session is scheduled but not yet started, the message DETECTION ON STANDBY
appears on the screen until the start time is reached, at which point the message changes to
DETECTION IN PROGRESS.
When the session is active, the icon blinks at the top of the screen, along with a status
bar showing the progress of the session. In addition, the (stop) button appears in place
of .
During the session, the Transient Count number is reduced by 1 every time a transient is
recorded. If this number counts down rapidly and appears as though it will reach zero well
before stop time is reached, we recommend stopping the session and setting the threshold
to a higher, less sensitive value. The session will continue until: (1) you press , (2) the
Transient Count limit is reached (see Step 3), or (3) the stop time/date is reached.
7. When the transient detection session is finished, it appears in the Detection List screen. You
can now open the session and view its contents, as explained in the following.

4
Viewing a Transient Detection Session
1. At the Detection Schedule screen, press the button.
For all other displayed screens, press the button, and then select Transient.
Either action displays the Detection List screen.
2. If more than one transient detection recording is stored, use the arrows to select the
desired recording, then press to open it.
In the preceding illustration:
1
Location in the record of the zone
displayed.
4
Move cursor to transient triggering time.
2
Instantaneous value of the signals
according to the position of the cursor on
the scale. Use ◄ and ► to move cursor.
5
Number assigned to displayed graph (e.g.
1 is highlighted indicating channel V1
triggered capture of the transient)
3
Move cursor to one period of the signal
before transient triggering time.
6
Zoom In/Out