As shown in figure "A" of the illustration, with a digital multimeter set up as an ohmmeter, what set of readings would be consistent with an open in phase "B" of the single circuit, wye-connected stator windings as shown? Illustration EL-0201
• Wye (star) connection of three stator windings and the common neutral point • How an open in one phase winding affects continuity between line terminals • Using an ohmmeter: normal winding resistance vs an "OL" (overload/open line) indication
• Draw the wye (star) connection and label which winding is between each terminal (T1, T2, T3) and the neutral point. • For each terminal pair (T1–T2, T2–T3, T3–T1), trace the complete path that current would take through the windings. Which pairs require current to pass through the open phase "B" and which do not? • If each good winding has about 0.9 ohms, what total resistance would you expect to measure when two good windings are seen in series between two terminals?
• Be sure you correctly identify which line terminals are connected to phase A, B, and C at the wye point. • Verify for each choice which terminal pair shows continuity through two windings and which pairs show no complete path (OL). • Confirm that only the pair(s) that do NOT need to pass through the open phase B should show a finite resistance (about 1.8 ohms), while any pair that must include phase B will read OL.
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