What does an ohm reading of 12 from R to ground in a hermetic compressor suggest?

An ohm reading of 12 from R (run) to ground in a hermetic compressor indicates a concern related to the start winding, particularly suggesting there is a small short to ground. In a typical hermetic compressor, the resistance readings are used to diagnose the condition of the windings and their insulation. A reading of 12 ohms is not a standard reading for healthy insulation; it indicates a significant drop in resistance, which can occur if the insulation has begun to break down, allowing some current to flow to ground.

When there is a small short to ground, it often means that the insulation within the compressor has degraded to the point that some of the coil windings are in contact with the compressor housing or ground. A reading like this can hint that while the compressor may not be completely shorted (which would typically show a much lower resistance), it is experiencing a failing condition which could lead to complete failure if not addressed.

Recognizing this type of reading is crucial for maintenance and troubleshooting, as it addresses the electrical integrity of the compressor and can prevent further damage or dangerous situations if the compressor continued to operate under these conditions.