Thermal imaging is a well-established method of detecting potential problems and issues in electrical systems. The thermal imagers that perform these vital tasks have changed significantly over the past several years, moving from expensive specialty tools to smaller, easier-to-use, more affordable models with broader capabilities.


Many thermal imagers feature wireless storage, and the range of models can meet almost every heat-detection and measuring requirement electricians encounter. Thermal imaging has been incorporated into some multimeters, essentially creating two tools in one.


“Once a costly ‘nice-to-have,’ thermal imagers now are an affordable ‘must have,’” said Tony Shockey, thermal product specialist, Fluke Corp. “Thermal imagers today are a minimum professional requirement for most electrical contractors and not only help to identify potential problems but are also used to document that identified problems have been properly fixed.”


Thermal imaging is designed to be a first-line troubleshooting tool for electrical equipment that can check hot spots of high-voltage equipment and transformers from a safe distance and detect heating of fuses, wires, insulators, connectors, splices and switches. Imagers provide a heat map that can quickly and safely locate hot spots before repairs begin and can validate that all problems are fixed after the fact.


The latest thermal imaging cameras are easy to use.


“Simple, intelligent menu design allows technicians to easily navigate the on-screen menu interface even while wearing gloves,” Shockey said. “Smart battery systems with LED charge indicators help prevent unexpected loss of power while on the job, while removable SD memory cards store thousands of images, more than enough for typical work periods. Designed for industrial environments, an electrical contractor can simply point and shoot and capture needed images, and quickly move on to the next inspection.” 


For basic electrical circuit breaker scans at approximately 4 feet, Shockey recommends a camera with 160-by-120 resolution. 


“This meets the minimum standard requirements for professional interpretation of thermal images,” he said. “For more in-depth analysis of panels and small wiring that requires you to get either closer or further away to conduct a safer inspection, users should look for cameras with 260-by-195 resolution, manual focus and a better DS [distance to spot].”


A thermal multimeter that combines two tools into one thermography product is an easy-to-carry, first-line troubleshooting tool. Such a tool also makes users more productive. Wireless connectivity and cloud storage allow image and reading sharing from the field, saving time and effort in resolving issues. 


Fluke thermal-imaging products include the affordable and easy-to-use Performance Series models; the Professional Series, which offers superior image quality and advanced features; and the Expert Series, which gives users premium viewing, an extensive feature set and highly detailed images. Expert Series models come standard with Fluke Connect to store asset images in one location for comparison over time and get work-order approvals or questions answered without leaving the field.


Sam Ruback, product manager at Flir Systems, said thermal imaging can help electrical contractors troubleshoot complex and compounded issues by enabling them to quickly find warm or overheating connections, and locate the root—not just the fault—of a component’s problem. 


Thermal imaging can help electrical contractors sort the list of potential issues, including the following:


• Finding unseen panel hazards in an electrical assembly before getting in to the area to perform the work


• Providing a quick scan of the panel, which can identify additional areas of work to add to a current work order


• Confirming new equipment is operating within specified temperatures and to validate work after a repair


“In addition, as renewable and green technologies have matured, we’ve found a few new applications for the traditional thermal imaging usages—for example, scanning rechargeable battery banks, inspecting solar panels and validating the reduced heat output of LEDs,” Ruback said.


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Regarding important changes in 
thermal-imaging equipment, Ruback cited integrating thermal imaging into other test and measurement equipment.


“We call it IGM [infrared guided measurement],” Ruback said.


IGM leads electricians to problems they can’t see with standard clamp meters by visually guiding the user to the precise location of a potential electrical issue, helping to safely identify dangerous and unknown problem areas.


“IGM also allows safer work because the electrician doesn’t have to switch between a thermal camera and meter which increases the time and movements in front of a panel,” he said. “Simplifying hand movements and reducing time spent in front of a live situation helps minimize safety risks.”


Ruback believes two influencers are helping drive the increased demand of thermal imagers.


“Thermal cameras are becoming more affordable for broader deployment in the industry, compared to a few years ago when a camera would be shared by a group. Now, the prices can support one thermal imager for every truck, contractor or technician,” he said. “Second, thermal imagers are being built to be more durable like other tools used on job sites—no longer are thermal imagers delicate instruments but [they are] go-to devices that can live in toolboxes.”


Flir offers a broad line of thermal imaging products, with models starting below $400. Advanced models feature multispectral dynamic imaging technology (MSX), which adds visible-spectrum detail to infrared images that add clarity and definition to the thermal image. Wi-Fi and Bluetooth capabilities allow sharing images and connection to Meterlink-enabled test and measurement equipment.


The new line of IGM test and measurement products integrates thermal imaging into traditional pieces of test instruments, such as moisture meters and clamp meters.


Ben Cabot, product manager at Milwaukee Tool, said a thermal imager is a valuable tool anywhere that heat or temperature variations can signify a problem. The most common equipment inspected in these applications are switchgear, breakers, bus ducts, fuse clips, transformers and capacitors.


“Demand is heavily driven by the decrease in cost of thermal-imaging tools, making it justifiable for a much broader set of uses,” Cabot said. “With the decrease in cost, electrical contractors are starting to look at leveraging the benefits of thermal imaging with their service teams. With the ability to equip more teams with high-quality thermal imagers, service managers can provide a new level of service—essentially providing more opportunities for proactive maintenance before issues become problems. This better protects facility stakeholders’ assets, gives them peace of mind and builds trust in the provider. It’s all about differentiating service from competitors and providing better service to customers.”


While there have been significant improvements in image quality, tool size and simplicity, one of the most notable changes has been the price. 


“The cost of thermal sensors has gone down dramatically, allowing users to purchase higher quality units for much less than they could even two years ago,” Cabot said. “This allows users to get a full return on their investment much faster than they could in years past, opening the door to a steady increase in the adoption rate for thermal imagers across the electrical trade. This is especially relevant in the adoption of thermal imagers for service technicians, as already noted.”


Simplicity is important.


“Thermal imagers have the potential to be very technical and complex tools, so, as contractors seek to provide thermal imagers to service technicians of varying experience levels, simplicity is key,” he said. “Users are demanding tools that are intuitive and simple to understand so that they spend more time doing work and less time learning how to use the tool.” 


Users also must evaluate the software that comes with the tool, not just the thermal imager alone. 


“Capturing thermal images is just the first step,” he said. “Users must also be able to quickly analyze the data and summarize issues that are found easily.”


Milwaukee Tool offers two thermal imager models: one with 160-by-120- pixel imaging, a camera for standard pictures and manual focus capabilities. The 7,800-plus-pixel model has proprietary Dual Sense technology for superior definition of hot and cold details in the same image.