Question 146Electricity & Electronics - QMED
70% to passA 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 "OL" ohms. From T2 to T3 reads "OL" ohms. From T3 to T1 as shown reads "1.6" ohms. What condition is indicated? Illustration EL-0219
APhase A (associated with T1
Bare short-circuited. Phase B (associated with T2
CB
Dand Phase C (associated with T3
AI Explanation
The correct answer is A) Phase A (associated with T1) are short-circuited. The reasoning is as follows: 1) The readings show that the resistance between T1-T2 and T2-T3 are both "OL" (open-loop), indicating an open circuit in those phases. 2) However, the reading between T3-T1 is 1.6 ohms, which suggests a short circuit in that phase (Phase A associated with T1). 3) The other options are incorrect because they do not accurately describe the condition indicated by the readings. 4) In summary, the multimeter readings indicate a short circuit in Phase A of the three-phase motor's stator windings.
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