Back to Basics Refresher: The Importance of Insulation Resistance Testing

Electrical insulation begins to age and thus deteriorate as soon as it is made. Exposure to harsh environmental conditions, such as extreme temperatures, mechanical damage, and chemical vapors, hastens deterioration. Ultimately, this can lead to safety and power reliability issues, and is the reason why performing routine insulation resistance (IR) testing is necessary.

According to former EC&M Editor in Chief John DeDad, insulation resistance testing can be used as:

• A quality control measure at the time a piece of electrical equipment is produced
• An installation requirement to help ensure specifications are met and to verify proper hookup
• A periodic preventive maintenance task
• A troubleshooting tool.

Before proceeding any further, you may want to refamiliarize yourself with Ohm’s Law, which plays an important role in IR testing. Then, get back to basics by reading the most relative articles we've run on this subject (click on the individual article links below):

• Understanding Insulation Resistance Testing
• Insulation resistance testing: How and why?
• What Is Insulation Testing?
• The Top 5 How-To Videos on Insulation Resistance Testing
• The Basics of Insulation Resistance Testing
• Insulation Resistance Testing, Part 1
• Insulation Resistance Testing, Part 2
• Insulation Resistance Testing, Part 3
• Insulation Resistance Testing, Part 4
• Insulation Resistance Testing, Part 5