The three major electrical defects in compressor motors that can be identified using an ohmmeter are:

The three major electrical defects in compressor motors that can be identified using an ohmmeter are:

• A. Open, shorted, or grounded
• B. Burned, corroded, or loose
• C. Overheating, undercooling, or vibration
• D. Leaking, blocked, or seized

Answer: (A)

The main idea is that an ohmmeter checks electrical continuity and winding resistance to reveal faults in motor windings. The three faults you can identify with this test are: - Open: the winding isn’t connected at all, so you get infinite or very high resistance. That means the circuit isn’t complete and current cannot flow where it should. - Shorted: there’s an unintended low-resistance path between conductors, often turn-to-turn or to another conductor. An ohmmeter will show a resistance that’s much lower than normal, indicating excessive current flow and a faulty winding. - Grounded: the winding has an insulation fault and is making an unwanted connection to the motor frame (ground). Measuring between the winding and the frame shows continuity to ground, which should not exist in a healthy motor. The other options describe mechanical or non-electrical issues (burned, corroded, loose; overheating/vibration; leaking/seized), which aren’t reliably detected by an ohmmeter.

The main idea is that an ohmmeter checks electrical continuity and winding resistance to reveal faults in motor windings. The three faults you can identify with this test are:

• Open: the winding isn’t connected at all, so you get infinite or very high resistance. That means the circuit isn’t complete and current cannot flow where it should.

• Shorted: there’s an unintended low-resistance path between conductors, often turn-to-turn or to another conductor. An ohmmeter will show a resistance that’s much lower than normal, indicating excessive current flow and a faulty winding.

• Grounded: the winding has an insulation fault and is making an unwanted connection to the motor frame (ground). Measuring between the winding and the frame shows continuity to ground, which should not exist in a healthy motor.

The other options describe mechanical or non-electrical issues (burned, corroded, loose; overheating/vibration; leaking/seized), which aren’t reliably detected by an ohmmeter.