Megger Baker AWA-IV User Manual page 71

Baker AWA-IV Software Overview
Resistance measurements can be influenced by humidity. To enable setting the relative humidity, check the Relative
Humidity box then enter the humidity present. Click on Accept to commit the settings.
The resistance test has several options. The test can be performed on a two-lead (single phase) device such as a
single coil or a three-lead (three-phase) device such as a three-phase motor. Resistance values can be automatically
acquired by the analyzer, or by some other means and manually entered into the software. The method for entering
or obtaining resistance data is described later.
You can tell the software to use low-voltage leads for resistance measurement (recommended when applicable).
The motor may have wye or delta winding configurations. The wye or delta configuration is entered in the Data tab
Nameplate view and the information is displayed here based on that entry.
Fig 62: Resistance enabled.
By checking the Delta R (%) box, the resistance values will have their percent spread calculated at the end of the
test. If the percent spread is outside the number entered in the corresponding field, the motor will fail the resistance
test.
The acquired resistance values can be temperature corrected by checking the Correct to box and defining the related
parameter in the adjacent field.
The temperature the resistance value is corrected to is set to 25° C by default, but it can be changed to another
value. IEEE 118 recommends 25º C. The constant used to convert resistances at one temperature to another is
known as the IEEE 118 constant and is 234.5 for copper or 224.1 for aluminum.
A motor that does not have a resistance reading within a target resistance range can also fail. Correct this issue
by checking the Target Corrected Resistance box and entering the expected corrected resistance values and
tolerances.
NOTE: Only temperature corrected values will be used in determining if values are within tolerance.
At the end of the test, the analyzer compares corrected resistance readings to the target corrected resistance to
determine if the motor passes.
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