Printing A Report; Ear - Baker Instrument Company PP24 User Manual

Surge Testing DR Unit
19) Switch the red test lead to the motor's Phase C lead as described above and repeat
the above steps.
20) Save the Phase C waveform to the Lead 3 memory location.
21) At the end of all three tests, an EAR (Error Area Ratio) can be calculated for the
three waveforms. (The EAR will be described later in this chapter.) The EAR is
calculated by pressing the Save button after all three waveforms have been saved.
Select the record chosen to store the waveforms and select the EAR Calc option.
22) Once the EAR is calculated, it can be saved by pressing the Save button.
23) Once all the data has been saved for both the HiPot and Surge tests, a summary
report can be printed as shown below.
This report contains all of the data for the HiPot and surge tests. If resistance tests were also
performed with the DR, resistance data would also be shown. (The winding being tested in
the photographs above has a welded fault in Phase 1 which is giving the large shifts seen in
the wave pattern. The winding is a 6.9kV stator without the rotor – the waveforms should
have been nearly identical with no visible shift.)

Printing a Report

A report for all the data taken above can be printed by connecting the DR's printer to the
parallel printer port. The most convenient report is the Summary report which is printed by
pressing the Recall button, selecting the record to be printed and pressing the Summary
button.

EAR

The Error Area Ratio (EAR) is a calculation that gives a quantitative measure of the difference
of two waveforms. Mathematically the formula is
12/7/2009 | 71-026 V2
PP24
Fig 3-6: EAR recorded
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