Question 127Electricity/Electronics - 1st Asst/Chief70% to pass
When testing the rotor of a synchronous motor for short circuits, a low voltage source is applied across the rotor coils through the collector rings. What would be the indication of a short- circuited coil?
AI Explanation
The correct answer is C) low or zero voltage drop reading, while the other coils will have higher readings.
When testing the rotor of a synchronous motor for short circuits, a low voltage source is applied across the rotor coils through the collector rings. If a coil is short-circuited, it will have a very low or zero voltage drop across it, as the short circuit effectively bypasses the coil. In contrast, the other (non-shorted) coils will have a higher voltage drop, as the current will flow through their resistance. This low or zero voltage drop is the indication of a short-circuited coil.
The other options are incorrect because they do not accurately describe the expected behavior of a short-circuited coil in this test scenario.
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