GE Industrial Solutions Entellisys 4.0 System User Manual - Manual (Page 141)

Waveform capture 141
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9.2 Waveform capture
Waveform capture is an optional feature which, when triggered, saves waveforms for all phases
on all breakers in the system simultaneously. The following channels are recorded from each
EntelliGuard Messenger:
•
Analog – Ia, Ib, Ic, In, Va, Vb, Vc (or Vba, Vbc, Vca for delta PT configurations)
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Discrete Command Transitions – Open, Close, and Trip
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Discrete Status Transitions – Open, Closed, Spring Charge, Analog IOC, Backup Trip
All channels for the entire system are time-synchronized to within 5us of each other. The
number of system-wide waveforms held in memory is dependent on the number of Messengers
in the system. The capacity can be calculated as the integer quotient of 1000/n, where n
represents the total number of Messengers in the system. Other specifications for waveforms
are:
•
Sampling Rate – 64 samples / cycle
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Duration – 1 second (60-Hz systems); 1.2 second (50-Hz systems)
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File Format – COMTRADE (IEEE Std. C37-111-1999)
Because of the large memory capacity of the CPU, these parameters are fixed for all captures.
9.2.1 Waveform capture configuration
Use the Waveform Capture configuration utility (from the User Settings menu, click Metering &
Waveforms) to set the following parameters:
Figure 9-6 Waveforms captured from an overcurrent condition
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Trigger Mode – In the default Automatic Overwrite mode, waveforms are overwritten in the
CPU memory on a FIFO basis. In Protected mode, waveforms stop being captured once the