If a measurement shows no expected resistance, what might that imply?

When measuring resistance in a circuit, a reading of no expected resistance can indicate a short circuit. In a short circuit, the resistance between two points is significantly lower than normal, typically approaching zero ohms, because the electrical path bypasses the intended load or components that should normally resist current flow. This condition allows current to flow through an unintended path, which results in a reading that reflects little to no resistance on the meter.

This scenario is a critical safety concern, as a short circuit can lead to overheating, damage to components, or even create fire hazards if not addressed promptly. Hence, identifying a short circuit based on resistance measurements is crucial in troubleshooting electrical circuits in HVAC systems.

Transforming the interpretation correctly helps with diagnostics; for instance, if a circuit is open, you would expect to see infinite resistance. Similarly, a blown fuse might still show some resistance depending on the state, while a meter being out of range could result in inaccurate readings rather than a complete lack of expected resistance.