MI 2892 Power Master
Theory and internal operation
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Current
t
I
Rms(1/2)
Trigger Point
Pretrigger
(1 sec)
Duration (2 sec)
Trigger:
Current level
Waveform record
µSD
Card
REC001.WAV
REC001.INR
}
Figure 5.23: Current Level Triggering (Inrush)
Alarms – instrument starts waveform recorder when any alarm from alarm list is detected. In
order to see how to setup Alarm Table, please check section 3.21.3.
Voltage events and alarms – instrument starts waveform recorder when either voltage event or
alarm occur.
Interval – instrument starts waveform recorder periodically, each time after given time interval
Interval: 10min finish.
User can perform single or continuous waveform recordings up to 200 records. In continuous
waveform recording, Power Master will automatically initialize next waveform recording upon
completion of the previous one.
Voltage event trigger
Waveform recorder can be set up to trigger on voltage events as shown on figure below.
Figure 5.24: Waveform recorder setup for triggering on voltage events
Inrush recorder
In addition to the waveform record which represent voltage samples, instrument also store RMS voltage
U
Rms(1/2)
and current I
Rms(1/2)
. This type of record is particularly suitable for capturing motor inrush. It gives
analysis of voltage and current fluctuations during start of motor or other high power consumers. For
current I
Rms(1/2)
value (half cycle period RMS current refreshed each half cycle) is measured, while for
