SKF AWAIV-12, User Manual, Page: 59 / 250

A resistance value that is manually entered will be different: a measurement made with a
bridge will be between two leads with a third lead allowed to float. Due to this difference, the
winding configuration becomes even more important. The Baker AWA-IV software assumes
that manually entered data will be made with a two-lead precision bridge and that the third
lead is allowed to float. Clearly, a Wye motor’s lead-to-lead measurement will be different
from a Delta lead-to-lead measurement.
Regardless of how the resistance measurements are acquired, after they are obtained the
software will calculate the temperature corrected resistances and display them. Additionally,
if possible, the Baker AWA-IV will calculate the individual coil resistances. If not, the software
will display a message indicating that a solution to the coil resistance that could not be found.
While the
Temperature / Resistance window is open, there are several ways to start an
automatic measurement:
1) Click the
Test All Leads button. The Baker AWA-IV then measures each lead’s
resistance sequentially.
2) Click one of the Lead buttons on the front panel of the Baker AWA-IV. The Baker
AWAIV then measures the resistance of the clicked lead only and displays the results.
Manually entered resistance measurements
Resistance measurements from high-precision resistance bridges can be manually entered
instead of having the Baker AWA-IV run an automatic resistance test. Manually entered data
should be line-to-line type measurements. To enable manual data entry, click the Manual
Entry radio button; then the results section of the Resistance test window shows measured
L-L above the Lead Resistance column. In this column of three edit boxes, the lead
resistances for the manual measurement should be entered as described below for the either
the wye-wound motor or the delta-wound motor. 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.
SKF Static Motor Analyzer—Baker AWA-IV User Manual 45
Baker AWA-IV software overview