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Manually Entering Resistance Measurements
Resistance measurements taken from the motor using a high-precision resistance bridge can be manually entered
instead of having the analyzer run an automatic resistance test. Manually entered data should be line-to-line type
measurements.
To enable manual data entry, click one of the manual entry buttons (Lead 1–2 (Ohms)); then the results section of
the Resistance test window enables the Measured L-L column so you can directly enter the lead resistances taken.
When you have finished entering data, click the Accept button.
Wye-wound Resistance Measurement
Using the NEMA nomenclature for a wye-wound motor, the resistance measurement for lead 1 should be made
between terminals 1 and 2 with terminal 3 left floating. This measurement will consist of coils 1–4 in series with coils
2–5. Likewise, the lead 2 measurement should be made between terminals 2 and 3 with terminal 1 left floating. The
lead 3 measurement should be made between terminals 3 and 1 with terminal 2 left floating.
Delta-wound Resistance Measurement
Using the NEMA nomenclature for a delta-wound motor, the lead resistance measurement should be made between
terminals 1–6 and 2-4. This measurement will be of coils 1–4 in parallel with the series combination of coils 2–5 and
3–6. The lead 2 measurement should be from terminals 2–4 and terminals 3–5. Likewise, the lead 3 measurement
should be made between terminals 3–5 and terminals 1–6.
After entering all data and clicking the Accept button, the measurements will be temperature corrected and
displayed in the Temp Corrected column. The coil resistances will also be calculated for the individual coils and
displayed in the Calculated Coil R column.
Coil Resistances
As discussed above, the resistance measurements made by the Baker AWA-IV are a user-configured series or a parallel
combination of coils. At the end of a resistance test, the analyzer will calculate and display the coil resistances. If
a temperature has been entered, it will report those values. These values are found in the right-hand column of
numbers in the Resistance window. The calculation involves numerically solving for the coil resistances given the type
of winding (wye or delta) and the measured balance values.
Under some circumstances, the algorithm may fail because it cannot return a valid result based on the values entered
manually. In such cases, the analyzer will indicate that it cannot find a solution given the balance resistance values.
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Baker AWA-IV Software Overview
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