Megger Baker AWA-IV User Manual page 78

Baker AWA-IV Software Overview
Use the P-P EAR (%) field to set the maximum Pulse-to-Pulse Error Area Ratio allowed for the test.
The Zero Crossing (%) option allows comparisons of the horizontal positions (time-offsets) where a waveform
crosses the zero reference line. A turn-to-turn fault is normally identified by a sudden increase in ringing frequency,
which appears as a surge waveform jumping to the left.
Enabling this option instructs the software to compare zero crossings, looking for too much movement in either
direction. The threshold value is a percentage of a zero crossing's time offset, specifying the maximum amount that
such an offset can change from one pulse to the next; anything beyond results in the motor failing the Surge test.
NOTE: Motors with heavy rotor influence can cause false failures when using Zero Crossing. Zero crossing measures
only frequency, whereas P-P EAR measures frequency and amplitude.
The remaining three columns (L1, L2, and L3) show real-time numbers for the specific lead while the test is running.
These numbers will become visible during the test. The number to the left of the "/" delimiter represents the last P-P
EAR taken for the test (for most passing tests, this will likely be 0 or 1) and the number to the right is the highest P-P
EAR recorded over the entire test.
Check the Test-Ref EAR (%) box to enable setting pass/fail criteria when comparing the surge waveforms from the
test to a previously stored reference test. If the field is disabled as shown in this example, a reference waveform has
not been set. See "Creating a Surge test reference" later in this chapter for details.
The four buttons on the right side of the window will run a Surge test when clicked. Clicking on the Lead 1 button
starts a manual Surge test on lead 1 only; likewise for the Lead 2 and Lead 3 buttons.
Clicking on the All Leads button starts a semi-automatic three-lead Surge test. A Surge test can also be started by
clicking one of the test buttons on the front panel of the analyzer.
66 Baker AWA-IV 71-015 EN V16 User Guide
Fig 69: Pass/Fail tolerances.
Fig 70: Run surge buttons.
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