Mechanism For Triggering Transient Sensors; Capture Conditions In Inrush Current Mode - AEMC PowerPad III 8336 User Manual

A.1.5 Mechanism for triggering transient sensors
The sampling rate is a constant 256 samples per cycle. When a transient capture is started, each sample is compared
to the sample from the preceding cycle. 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 representation of the transient is
then captured by the instrument. The cycle preceding the event and the three following cycles are saved to memory.
The following is a graphical representation of the transient capture trigger mechanism:
Item Function
1
Reference period
2
Top of envelope
3
Cycle monitored
4
Bottom of envelope
5
Triggering event
A.1.6 Capture Conditions in Inrush Current Mode
Captures depend on the trigger event and a stop event. If the capture ends with a stop event or if the recording memory of
the Model 8336 is full, the capture stops automatically.
The stop threshold for capture is calculated as follows:
[Stop threshold [A]] = [Start threshold [A]] × (100 – [Stop hysteresis [%]]) ÷ 100
The following table shows the conditions for triggering and stopping capture:
Triggering
filter type
Triggering condition ó [A1 half-cycle RMS value] > [Triggering threshold]
A1
Stop condition ó [A1 half-cycle RMS value] < [Stop threshold]
Triggering condition ó [A2 half-cycle RMS value] > [Triggering threshold]
A2
Stop condition ó [A2 half-cycle RMS value] < [Stop threshold]
Triggering condition ó [A3 half-cycle RMS value] > [Triggering threshold]
A3
Stop condition ó [A3 half-cycle RMS value] < [Stop threshold]
Triggering condition ó [the half-cycle RMS value of one current channel] > [Triggering threshold]
3A
Stop condition ó [the half-cycle RMS values of all current channels] < [Stop threshold]
134
0
Triggering and stop conditions
1
2
3
4
5
Power Quality Analyzer PowerPad III Model 8336
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