Which instrument is used to test insulation resistance?

Which instrument is used to test insulation resistance?

• A. Meggers
• B. Crimpers
• C. Torque wrench
• D. Nut driver/socket sets

Answer: (A)

Insulation resistance is tested with a megohmmeter, commonly called a megger. This instrument applies a high DC voltage across the insulation and measures the resistance in megohms. A very high resistance indicates good insulation with minimal leakage current; a low reading shows leakage paths, such as moisture, damage, or aging insulation, which could lead to faults or safety hazards. When using it, ensure the equipment is fully de-energized and isolated, select a test voltage appropriate for the equipment’s rating (for example, around 500 V DC for low-voltage gear or 1000 V DC for higher-rated gear), and measure between conductors or from conductor to ground as required. After testing, discharge any stored charge and compare the result to acceptable limits per standards or manufacturer specifications to assess integrity. Tools like crimppers, torque wrenches, or nut driver/socket sets don’t measure insulation resistance; they’re used for mechanical work and connections, not electrical insulation testing.

Insulation resistance is tested with a megohmmeter, commonly called a megger. This instrument applies a high DC voltage across the insulation and measures the resistance in megohms. A very high resistance indicates good insulation with minimal leakage current; a low reading shows leakage paths, such as moisture, damage, or aging insulation, which could lead to faults or safety hazards. When using it, ensure the equipment is fully de-energized and isolated, select a test voltage appropriate for the equipment’s rating (for example, around 500 V DC for low-voltage gear or 1000 V DC for higher-rated gear), and measure between conductors or from conductor to ground as required. After testing, discharge any stored charge and compare the result to acceptable limits per standards or manufacturer specifications to assess integrity. Tools like crimppers, torque wrenches, or nut driver/socket sets don’t measure insulation resistance; they’re used for mechanical work and connections, not electrical insulation testing.