An infrared temperature gun is a fast, non-contact way to detect heat-related issues in electrical systems—before they become costly or dangerous. Whether you're maintaining facility switchgear or troubleshooting power panels, using an infrared temperature gun properly helps you inspect safely, prevent failures, and reduce downtime.
In this step-by-step guide, you’ll learn how to conduct effective and safe electrical inspections with your infrared temperature gun.
Step-by-Step Guide to Performing Electrical Inspections Safely with an Infrared Temperature Gun
Step 1: Understand What You’re Looking For
- Create a checklist of typical inspection points (e.g., circuit breakers, bus bars, fuse blocks).
- Reference normal operating temperature ranges when possible.
Electrical systems generate heat under normal operation, but abnormal heat can signal trouble—like a loose connection, overloaded circuit, or failing component. Identifying thermal irregularities early can prevent equipment failure or fire hazards.
Step 2: Inspect with Safety in Mind
- Wear proper PPE and follow lockout/tagout procedures when needed.
- Always maintain safe distance and avoid direct contact with live components.
Electrical inspections come with risks, especially in high-voltage areas or tight enclosures. A non-contact tool like an infrared temperature gun allows you to inspect without exposing yourself to energized parts.
Step 3: Use the Right Distance-to-Spot Ratio
- For small components like fuse terminals or cable lugs, get close enough to isolate the specific area. Check your device’s specs for the best distance.
Your IR gun’s distance-to-spot (D:S) ratio defines how close you need to be for accurate readings. If you're too far, the gun may average temperatures over a broader area, including cooler or hotter surroundings.
Step 4: Scan Panels and Components Methodically
- Start at the top of a panel and move methodically downward.
- Measure both ends of fuses, terminals, and power connections to identify temperature differences.
A structured scanning approach helps ensure you don’t miss key inspection points. A missed hotspot could lead to a preventable failure. If applicable, set Hi and Lo alarms to visually or audibly indicate when a reading is above or below a set threshold or set limits.
Step 5: Compare Across Phases and Loads
- Take readings at equivalent points on all phases. Any significant temperature deviation warrants further investigation.
Balanced three-phase systems should produce similar temperatures across each phase. Temperature differences between phases can signal an unbalanced load, loose connection, or equipment issue.
Step 6: Adjust for Reflective Surfaces
- Apply a piece of electrical tape or use a non-reflective label to the measurement area for improved accuracy.
- Another way around low emissivity levels is to either paint the surface or put tape on it so you can get accurate readings without changing the emissivity, both tape and paint emissivity are 0.95.
- Alternatively, use a gun with adjustable emissivity settings.
Shiny or polished metal surfaces reflect infrared energy poorly and can cause misleading readings. Many electrical enclosures, terminals, and lugs are made of low-emissivity materials.
Step 7: Consider Environmental Influences
- Try to shield your readings from air movement.
- Avoid measuring near vents or in direct airflow paths.
Dust, steam, or ambient airflow can distort IR readings. Even in electrical rooms, airflow from fans or HVAC systems can cool surfaces artificially.
Step 8: Track and Compare Readings Over Time
- Use logs, spreadsheets, or thermal inspection software to document temperatures at each inspection point.
- Note environmental conditions, date, and load level when possible.
Repeated measurements allow you to spot trends and predict failures. A one-time snapshot may miss an emerging issue, but historical comparisons can reveal rising temperatures over time.
Step 9: Know When to Investigate Further
- Investigate abnormal temperatures with follow-up visual inspection or contact-based tools. If unsure, consult equipment specs or bring in an electrical specialist.
An elevated temperature isn’t always a problem—but it often is. A temperature that’s just 10–20°F higher than normal may point to a loose lug or failing breaker.
Summary: Best Practices for Electrical Inspections with an IR Temperature Gun
- Prioritize safety and wear proper PPE.
- Know typical inspection targets and temperature expectations.
- Get close enough to respect your tool’s D:S ratio.
- Scan methodically from top to bottom.
- Compare readings across phases and connections.
- Account for low-emissivity surfaces.
- Watch out for airflow and other environmental distortions.
- Record data and track trends over time.
- Investigate hot spots or anomalies promptly.
Infrared temperature guns give you the power to detect electrical issues before they escalate into emergencies. By following these steps, you’ll perform safer, smarter inspections—protecting both equipment and people.