What does a megger measure?

A megger, formally known as an insulation resistance tester, is specifically designed to measure the insulation resistance of electrical circuits. This device applies a high-voltage test signal to the insulation of wire and electrical equipment, allowing for the assessment of insulation quality and integrity. Poor insulation can lead to short circuits, electrical leakage, or equipment damage, making it crucial for safety and performance evaluations.

Measuring insulation resistance is a preventive maintenance practice that identifies potential problems before they result in failure or hazards. It helps ensure that the material used to insulate electrical conductors is functioning effectively and that the circuits are safe for operation. The other options, while relevant to electrical testing and measurements, do not pertain to the specific function of a megger, which is aimed at assessing insulation rather than voltage drop, current flow, or power factor.