How do you know if a compressor is grounded?

To determine if a compressor is grounded, you can use a multimeter to check for continuity between the compressor's metal casing and the ground wire or ground point. If the multimeter shows continuity (a low resistance reading), the compressor is grounded. Additionally, you can visually inspect the grounding connections to ensure they are secure and free of corrosion. If there are any issues with the grounding, the compressor may not operate safely.