I recently published an article on the basic (qualitative) use of a thermal camera.
Shortly after this publication I performed a thermal survey on an electrical installation. The findings were significant. I thought it best to create this instructable to share such a wealth (yes wealth!) of on-site data. This will be particularly useful to fellow electrical personnel like myself.
Notes to remember when performing a thermographic survey on electrical systems:
1. Know the target system and plan your work beforehand.
2. All images will be taken of a LIVE electrical system so you are in charge of the area during the survey.
3. Wear appropriate PPE for energized electrical work. Although you wont be coming in contact with electrical conductors, you MUST wear the PPE.
4. Have a trained assistant available regadless if you have to remove a heavy panelboard cover or there is no manual handling.
5. Do not attempt immediate corrective action upon detection of issues. This will be a planned exercise in the upcoming future.
6. Have your Job Hazard Analysis and Work Permits completed and approved! We dont go gung ho into electrical work. We usually have one attempt to do a proper job and its only one attempt we need!
Now lets continue to the instructable.
Step 1: Taking Visual and Thermal Images.
It is important to take a visual followed by a thermal images for side by side comparison. Any electrical equipment needs to have its cover plate removed for this.
Nice, clear, non-blurry images are critical for good analysis. Take as many images for later analysis.
In the photos I have the shots of a 3-phase panelboard.
Step 2: Taking Images of Components With Possible Issues.
Here I am giving an example on the main breaker for the panelboard. Looking at the thermal images shows significant loading on the red and yellow phases at the lineside of the breaker. On the loadside the yellow (middle) phase shows signficant heating.
Why is this? With thermography we can immediately find problems but we need to use other test technologies to determine the exact cause of the problem(s). Thermography alone cannot be used to diagnose!
Step 3: Auxiliary Tests.
I used my clamp ammeter to measure the currents on the phases. The red was 86A, yellow 106A and the blue 34A. Severe imbalance yeah? I also suspect the lugs needed torque tightening. Voltages were all good on the phases.
For my report I made my recommendations. The thermal camera made it possible to quickly find a problem. This camera can be applied to mechanical, process, fluid etc systems so allow quick problem detection.
I hope this instructable has been informative. Stay tuned for more thermal imager instructables where I show basic troubleshooting in different applications!