A technician is inspecting a single-phase hermetic compressor motor running on 240 V. Using an ohmmeter, the resistance readings are as follows: Run to Common (RC) = 1.5 Ω, Start to Common (SC) = 3.0 Ω, Run to Start (RS) = 4.5 Ω. Based on these readings, what should the technician conclude?

Question: A technician is inspecting a single-phase hermetic compressor motor running on 240 V. Using an ohmmeter, the resistance readings are as follows: Run to Common (RC) = 1.5 Ω, Start to Common (SC) = 3.0 Ω, Run to Start (RS) = 4.5 Ω. Based on these readings, what should the technician conclude?

Answer options: ✅ The motor windings are healthy and properly identified.

• There is a short circuit in the run winding.
• The start winding is open.
• The common terminal is misidentified.

Correct answer: The motor windings are healthy and properly identified.

Explanation: For a single-phase compressor motor, the resistance between Run and Common (RC) should be the lowest, Start and Common (SC) should be higher than RC, and Run to Start (RS) should be approximately the sum of RC and SC. In this case, 1.5 Ω (RC) < 3.0 Ω (SC) and 1.5 Ω + 3.0 Ω = 4.5 Ω (RS), indicating healthy and correctly identified windings.