Question 124Electricity & Electronics - 1st Asst/Chief

70% to pass

A digital multimeter is set up as shown in the illustration to evaluate the single-circuit stator windings of a squirrel cage induction three-phase motor. The following readings are taken: From T1 to T2 reads 1.6 ohms. From T2 to T3 reads "OL" ohms. From T3 to T1 as shown reads "OL" ohms. What condition is indicated? Illustration EL-0219

Diagram for USCG Electrical Chief: A digital multimeter is set up as shown in the illustration to evaluate the...
APhase A (associated with T1
Bare open-circuited. Phase C (associated with T3
CB
Dand Phase B (associated with T2
AI Explanation

The correct answer is A) Phase A (associated with T1) is open-circuited. The reasoning is as follows: - The reading of 1.6 ohms between T1 and T2 indicates that the winding associated with Phase B (T2) is intact. - The "OL" (open-loop) readings between T2-T3 and T3-T1 indicate that the windings associated with Phase C (T3) and Phase A (T1) are open-circuited. - This means that Phase A (associated with T1) is the winding that is open-circuited, which is the correct answer (A). The other options are incorrect because: B) is incorrect as Phase C (associated with T3) is not the open-circuited winding. C) and D) are incorrect as they do not correctly identify the open-circuited phase.

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