Well, it all depends on the subject matter.
When it comes to cooking, temperature plays a significant factor on the timing, look, taste, and overall presentation of the dish. Imagine you and your family are out to a nice steak dinner, and everyone orders according to their tastes: well-done, medium, rare, and so-on. When the steaks arrived and were cut open, did the temperature of the meat matter? You bet it did! Each cut of meat required a different temperature to achieve the desired degree of “doneness” for each person’s tastes.
Now let’s consider an infrared scan at your facility. Will a temperature reading really tell you what the problem is? How useful are these readings? How hot is too hot? Are there different temperatures for different problems?
I know what you’re thinking, and you probably want to say, “Isn’t the purpose of the infrared scan to show me hot spots?” Normally you would be absolutely right, BUT, let’s try and approach this explanation a little differently.
What would be hotter to the touch: holding a light bulb in your hand, or touching the bulb of a lit lamp? The answer is obvious, but the application of this example may not be. Let me walk you through this:
The light bulb in the lit lamp will be hotter because load is running through the bulb. The same happens in your electrical system. When there is load passing through your system will there be heat present in the components. Heat is created as a result of normal operation; therefore, a certain amount of heat is acceptable across the board. Not all heat is bad heat, and hot spots should lead a qualified inspector to diagnose the problem. But some instances during an inspection are not always that simple.
Looking at this picture, what do you think the heat would tell an inspector? Is it a hot connection? Is it a bad breaker? Or is it a load issue? This could be a load issue, but further testing showed that the load was the same. The next step, conducting a resistance check, revealed that the breaker had an internal hot spot and needed to be replaced.
Let's take a look at another scan:
Here, we have heat on the breaker, but does that mean it’s bad? Further investigation of the load showed it was running at 14-15 amps with a low resistance reading. Both are acceptable.
One more example:
Again, we have heat present on a specific wire connection. We started our investigation and found the load to be even with the other conductors. Checking the resistance showed an issue in the lug, and a visual inspection revealed that the lug was never fully tightened. While we had a temperature difference initially, that was not enough to fully diagnose the problem. A qualified infrared technician will know the proper steps to take in diagnosing the real cause of a hot spot.
Sometimes a hot spot will be hundreds of degrees, burnt, and obvious to the eye. More often than not, they present as smaller temperature differences, both internally and on the surface of your electrical components. Remember, these differences in temperature are what inspectors use to determine where to start looking for problems. And because not all heat is bad heat, it is important for a technician to understand the difference between a potential problem, and normal operating temperature.
As with any profession, there is no substitute for the experience gained through time and practice. Consider how an X-Ray technician spends years studying hundreds of scans to visually understand our internal composition. Or how a banker can identify a fake bill by touch alone, simply because of the volume of cash they handle every hour.
In the same sense, an experienced infrared technician with the right equipment, diagnostic tools, and training will be able to visually understand the scans during an inspection. And when your inspector is experienced enough to distinguish operating temperature from a potentially dangerous hot spot, their attention to detail will save you money on repairs and unplanned outages. Just remember, with SI Testing, you can always be sure the job will be “well-done”.