How to Test Electrical Cable Insulation Resistance Using a Megger
Insulation resistance testing is a critical procedure in ensuring the safety and efficiency of electrical systems. Developed in the early 20th century, insulation resistance (IR) testing remains one of the oldest and most widely used methods for evaluating the quality of electrical insulation. This test measures the resistance of a device’s insulation to ensure it meets international safety standards. Let’s explore how to conduct this test using a Megger and its significance. What Is an Insulation Resistance Test? The insulation resistance test measures the ohmic value of an insulator under a stable direct voltage. It is performed using a device known as a megohmmeter (or Megger). This test helps detect issues like aging, degradation, or contamination of the insulation. The resistance values obtained are expressed in megohms (MΩ), gigaohms (GΩ), or even higher units, depending on the equipment used. Good insulation offers high resistance, while degraded insulation shows lower resistance,…
