Thermography Method of Inspecting Electrical Equipment

Electric equipment is vulnerable to wear and tear just like any other mechanical component, especially when it carries a substantial current load for a significant part of its operational time. Thermography is the latest technology being used for the inspection of electrical equipment and systems. There’re multiple advantages of using thermography to inspect energized electrical components, including reduced downtime, prevention of component failure, colossal maintenance cost savings, and minimizing injury and death risks.

Thermography can accurately detect poor connections, damaged insulation, unbalanced loads, or any other issues. Electric equipment is an active and energized electrical component, leading to excessive power, high maintenance costs, or complete equipment failure. Electrical equipment issues can result in unscheduled service interruptions, permanent equipment damage, or other unwarranted problems.

Thermography Inspection – The Science of Heat Sensing


The entire working of a thermographic imaging or infrared device is based on sensing heat emitted from an object’s surface. Thermography is all about detecting the temperature changes and producing images with different colors representing different temperatures. Infrared radiation is converted into a temperature value or thermal image, which can be used to assess the thermal condition at inspection time. Even though there’re various tools used for inspecting electrical equipment, thermography has emerged as the preferred technology because of the accuracy in readings and non-invasive features. An infrared camera is often used for the thermographic inspection of the electrical systems.

Advantages of Thermographic Inspection of Electrical Equipment


Fire incidences linked to faulty electrical equipment amounts to 10% of the total number of fire-related accidents. Faulty electrical systems include leakage in electrical insulation, faulty terminals, and several other faulty electrical components. There are specific guidelines for the regular compliance and maintenance of electrical equipment in the Electricity at Work Regulations Act 1989, Health & Safety at Work Act 1974, and BS 7671.

The thermographic method of inspecting electrical equipment under load will exhibit anomalous temperatures that can be captured by the thermography device. We are all aware that faulty electrical systems or wiring can result in electrocution injuries as they are exposed to live circuits. At times accidents due to faulty electrical equipment lead to severe injuries and death. Infrared imaging cameras are capable of detecting the high-resistance sections in electrical equipment. The early detection of faults and issues plaguing electrical equipment facilitates quick maintenance and repair. Thus, it’s possible to avoid unnecessary expenses by carrying out preemptive maintenance of faulty components.

Another considerable benefit of thermographic inspection of electrical equipment is that the equipment owners can realize multiple financial benefits in energy conservation, prevent unnecessary breakdowns, and reduce repair charges. Electrical components are subject to heavy loads, and this can lead to noticeable wear and tear. This ultimately results in high resistance, increased flow of current, and greater power consumption. A rise in the current draw will result in damaged or collapsed fuses, transformers, and circuit breakers. All these failures come as a surprise and result in unnecessary and repair or maintenance costs while also causing interruptions in business operations.

Thermographic Inspection of Electrical Equipment


  • Assessment of installation or maintenance of the electrical equipment
  • Reduces downtime
  • Reduces the incidences of equipment failure
  • Improves safety
  • Insurance claim settlement is quicker when there’s an inspection report in hand
  • Improves the performance of the equipment
  • Detect whether the electrical components are working correctly or not
  • Determines compliance of electrical equipment with the project design and specifications
  • Prevents unnecessary delays in the construction schedule
  • Save money
Thermographic Method of Inspecting Electrical Equipment


Thermographic imaging of electrical equipment is an efficient and effective method of inspecting electrical equipment. The inspection is usually carried out by a trained and experienced professional. The inspection method is entirely non-invasive and can be completed while maintaining a safe distance from the electrical equipment.

The best thing about the thermographic method of inspecting electrical equipment is that it is an entirely non-invasive method. Thus, you can inspect without shutting down the electrical equipment or plant operations. Additionally, there’s no risk of injuries to the inspector or maintenance staff as the inspection is carried out from a safe distance.

Electrical equipment is utilized in industrial, manufacturing, and commercial buildings, so production comes to a standstill in factories when there’s electrical equipment failure, resulting in substantial financial losses. Thermography is an effective and efficient tool to detect problems in the equipment in their early stage, understanding its severity. Thus, maintenance teams can take preemptive repair and maintenance work as and when needed. To prevent dangerous and expensive electrical outages, it is important to take preemptive steps.

The thermography method of inspecting electrical equipment captures heat distribution images, which helps the thermographers, detect the exact problems, and mark the sections experiencing the problems. As mentioned earlier, testing electrical equipment using thermographic images is based on the simple yet effective scientific phenomenon wherein all surfaces emit infrared radiation. Electrical equipment that exhibits an increased temperature is the ones that are experiencing more excellent resistance in the circuit and hence need to be repaired or replaced. Thermographic tools can easily capture the images of points experiencing increased temperature reading and then produce colored maps with different temperature readings. All this helps the thermographers analyze and assess the images to detect the sections experiencing overheating.

Detailed reporting based on the thermographic images is prepared for the maintenance and repair team. All the reports provide a comparative analysis of temperature readings of electrical components in their energized states. Any faulty component increases the resistance, which in turn leads to overheating or an increase in temperature. The heat patterns can be easily captured by a thermographic tool. These images and reports can be analyzed to assess the existing condition of the electrical equipment. A more in-depth analysis can accurately assess the level of damage or gravity of the issue. The maintenance staff can now be provided with detailed reports so that the necessary repair and maintenance of the electrical equipment is carried out before the components completely break down or collapse.

How thermographers inspect electrical equipment?


Thermographers are certified, trained, and qualified to handle different thermography tools, including the software used for the analysis of thermographic images. They’re competent enough to handle the inspection of commercial, power plants, manufacturing facilities, schools, college, sub-stations, medical facilities, etc. Electrical equipment can suffer from various problems, and a thermographer can quickly inspect and pinpoint the issues plaguing the electrical equipment.

Thermographers usually take the help of an infrared or thermal imaging camera to inspect the electric equipment. The heated electrical equipment will release a lot of heat in thermal energy, and the thermal imaging camera can easily capture this. Once the photographs are taken, they’re fed to software to provide thermal images or temperature readings marked with different colors for different temperatures. The temperature anomaly can be converted and presented in an easily readable format.

The thermographer will carry out the entire inspection without switching off the electrical equipment because thermal imaging is a non-invasive procedure, which can be completed while the electric equipment is in an energized state. Owners of the electrical equipment need not worry about switching off or transporting the equipment for inspection.

Thermography is a non-invasive method, and it can detect the following issues of electrical equipment:

  • Hot spots
  • High resistance in electrical circuits
  • Overloading of cables
  • Heating issues in Fuses or breakers
  • Faulty conveyor or motor
  • Motor windings getting overheated
  • Overheating in the distribution system
  • Uneven Phase load
Things to keep in mind while inspecting electrical equipment


It’s essential to test the electrical equipment when it’s operational. The thermographer will put adequate load and check the equipment in an energized state. Additionally, the equipment must be examined thoroughly from outside without removing the cover. In case there’s overheating, then the thermographer must call in for additional support by the maintenance team.

Once the initial inspection from a distance is completed, the thermographer must open the lids and covers to expose the internal wiring and circuit. Now, again the same process of thermal imaging must be carried out while the equipment is operational. Precise imaging is possible only when all the sections of the electrical equipment are accessible to the thermographer. Thus, all the covers must be properly removed to expose the internal sections.

The results of a thermographic inspection can either be qualitative or quantitative, and it must always be the prerogative of the thermographer. Often the thermographer chooses to use thermal imaging cameras instead of imaging radiometer during a quantitative inspection. It must ensure that the captured images are good enough to reveal all the details. Thus, it’s equally important to consider factors like resolution, focus, contrast, and lighting.

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