Which instrument is used to test insulation resistance?

Which instrument is used to test insulation resistance?

• A. Torque wrench/screwdriver
• B. Meggers
• C. Crimpers
• D. TIC Tracers / Voltage Tester

Answer: (B)

Testing insulation resistance means measuring how well electrical insulation resists leakage current. The tool designed for this is a megger, short for megohmmeter. It applies a high DC voltage to the insulation and measures the leakage current, giving a resistance value in megohms. A high resistance indicates good insulation; a low value signals deteriorated or compromised insulation that could lead to faults or shocks. This type of test is commonly used on motor windings, cables, transformers, and switchgear to catch insulation problems before they cause outages. The other tools mentioned serve different purposes and don’t measure insulation resistance. A torque wrench or screwdriver is for applying precise mechanical torque. Crimpers are used to make secure electrical terminations. TIC tracers or voltage testers are used to locate circuits or verify the presence of voltage, not to quantify insulation resistance.

Testing insulation resistance means measuring how well electrical insulation resists leakage current. The tool designed for this is a megger, short for megohmmeter. It applies a high DC voltage to the insulation and measures the leakage current, giving a resistance value in megohms. A high resistance indicates good insulation; a low value signals deteriorated or compromised insulation that could lead to faults or shocks. This type of test is commonly used on motor windings, cables, transformers, and switchgear to catch insulation problems before they cause outages.

The other tools mentioned serve different purposes and don’t measure insulation resistance. A torque wrench or screwdriver is for applying precise mechanical torque. Crimpers are used to make secure electrical terminations. TIC tracers or voltage testers are used to locate circuits or verify the presence of voltage, not to quantify insulation resistance.