Electrical Thermal Imaging Inspections

Electrical Thermal Imaging Inspections

Over the last few years facility management companies are seeing the importance of electrical infrared inspections for their predictive maintenance programmes.

Thermal imaging is essential in electrical predictive maintenance programs because it identifies potential faults and allows for swift inspections and one image can show you various detail unlike using a spot pyrometer where you would have to test individual fuses, this allows maintenance teams to undertake remedial works before critical asset failure.

At APT Thermal Imaging we can analyse your assets and provide you with unique easily understandable thermal imaging reports. That can be rolled out within your predictive maintenance programs. Also, also if you need help analysing the data provided within the thermal inspection report you will have your own dedicated thermographer at hand to explain everything in layman’s terms.

Contact us today If you require an electrical infrared thermal imaging survey. Our professional and certified Level 2 Thermographer’s will carry out your thermographic Inspections for BREEAM compliance in accordance with all necessary standards and current regulations.

All we need are a few details such as floor plans and elevation drawings and the building location to provide a quotation. We will also send across our informative checklist to help you prepare for the thermal survey.

Electrical maintenance thermography can be used on a wide range of electrical equipment including:

  • Distribution boards and fuse boards
  • Switchgears and switchboards
  • Control panels
  • Busbar systems
  • Transformers
  • High voltage systems
  • Batteries
  • UPS systems

It’s a very cost-effective way of ensuring that your electrical system doesn’t burn out or break down. This is especially important in industries with high voltage systems and/or where continuity of power is critical to the business, e.g. data centres, banks, utility suppliers, manufacturing, hospitals.

The most common benefits are:

  • Extension of equipment/building life
  • Less plant (critical asset) down time
  • Less energy wasted through inefficient operation.
  • The ability to prioritise and better target preventive maintenance
  • The avoidance of consequential damage to plant or facilities from fires/short circuits

Yes, our electrical thermal imaging surveys are carried out while plant and equipment is running. There will be no interruption to electrical supplies and your operations (critical assets) will not be affected while the thermal survey is being undertaken. Our thermal inspections engineers are all certified electrical professionals with extensive experience in thermal scanning of electrical systems and undertaking a safe system of works is their top priority.

Thermal imaging inspections can help to prevent fires, explosions, or breakdowns. It can find loose connections, overloaded and/or fatigued components, uneven voltage distribution and blockages in cooling tubes of transformers. The principal advantage over other types of testing and inspection is the ease with which components can be checked in a non-intrusive and safer way. Other benefits are normal operations can continue unabated with limited downtime and large installations with hundreds of electrical installations can be covered in a short space of time.

There are literally hundreds of different types of buildings that require thermal imaging inspections to their electrical installations, they are:

  • Office Blocks
  • Hospitals
  • Server rooms
  • Data Centres
  • Industrial Plants and facilities.
  • Warehouses & Cold Stores
  • Shops and stores
  • Backup generators and UPS Rooms

There is a very important and simple answer – all our thermal imaging engineers are trained to level 3, which is the highest level you can achieve as a thermographic engineer. We also use large format thermal imaging cameras; this provides you with the absolute best chance of solving any potential issues by utilising thermographic technology.

Our specification includes:

  • Level 3 thermographic certification
  • Level 3 qualified thermographers
  • Large format FLIR cameras with 45-degree lenses

As our level 3 certified electrical thermal imaging surveyors are trained to a minimum of Level 3 and use only the highest resolution thermal imaging equipment, its means we can keep further away from the danger zone. Our engineers also have a vast amount of experience in conducting this type of survey which further lowers risk.  We issue a risk assessment and method statement for each and every survey we undertake.

Our team of Level 3 certified professional Thermographers are highly experienced in carrying out thermal imaging surveys and have many years’ experience in all aspects of engineering, construction, maintenance, management, and professional survey work. Our thermal imaging equipment is some of the most accurate on the market, ensuring we pick up faults that other equipment may miss.

Our reports are professionally presented and are clear, concise, and easy to follow. We endeavour to give our clients a first class service every time. Here is a


Thermal Imaging Service

  • Supply of an ITC trained thermographer and level II reporting assessment using a large format FLIR P6n-Series (640×480 resolution) thermal imaging camera.
  • To supply an external thermographic inspection of the electrical systems, taking into account, distribution boards, fuse boards, Switchgears, switchboards, Control panels, Busbar systems and Transformers.
  • Looking for loose connections, overloaded and/or fatigued components, uneven voltage distribution and blockages in cooling tubes of transformers



  • Single report to include Introduction and fault cover pages, summary problem pages, elevation inventory,
  • Detailed fault documentation pages with possible root cause and remedial recommendation (isotherm included if using equations), baseline IR and DC image of every area (100% coverage-no isotherm)
  • Application of thermal indexing formulas
  • Eco Friendly Email Report

Highly qualified thermographer’s usually produce better quality and more technically consistent inspections. Highly trained Level 3 thermal engineers have the ability to troubleshoot, calibrate equipment, interpret data, and create reports.

It also allows our engineers to develop inspection procedures and severity criteria for our clients, as well as interpreting relevant codes, and manage a client-based thermography program, including overseeing and providing training and testing, and calculating the return on investment for the program.

When you are employing a thermographer, you should check to see that they incorporate the high specifications possible for their inspections. Are they certified to Level 3 and do they use large format FLIR thermal imaging cameras?

Their specification should include:

  1. Level 3 thermographic certification
  2. Level 3 qualified thermographers
  3. Large format FLIR cameras with 45-degree lenses

Our thermal imaging reports have been set up to satisfy the requirements expected by insurance companies, facility managers and safety auditors. Our electrical thermographic inspection reports usually comprise of the following four sections:

  • Introduction/Report Summary – This section provides details on the survey carried out along with summary of the overall findings.
  • Main Body Report Pages – this section explains where faults/anomalies are identified, an individual report page is produced providing a description of the fault, its severity and recommended remedial action.
  • Condition Monitoring Assessment – this section provides an understanding of the current operational condition of equipment that have been reported during previous surveys – an ongoing assessment if you will.
  • Appendices – This section provide a checklist along with images of every asset inspected during the survey. This provides an auditable record of what was inspected, together with equipment health at the time of the thermographic survey.

Electrical infrared thermal surveys are incredibly useful for various purposes within new and existing buildings, such as:

  1. Saving time & money: by reducing downtime, maintenance costs, and energy consumption.
  2. Improving quality and productivity: by optimizing the electrical systems operation and performance.
  3. Reducing risk: By identifying potential problems before they cause damage or failure, electrical thermal surveys can prevent costly downtime, repairs, or accidents.
  4. Lowering energy costs: By finding poor connections or inefficiencies that waste energy, electrical thermal surveys can help lower annual bills and improve environmental performance.
  5. Extending the lifespan of equipment: by improving the serviceability of electrical equipment by preventing premature wear and tear
  6. Fulfilling insurance requirements: Some insurance companies may require or recommend electrical thermal surveys as part of their risk assessment or policy compliance.

To enable us to carry out your electrical thermal imaging inspection, we will require the following site conditions.

  1. All electrical and mechanical equipment to be running under normal load patterns.
  2. Areas should be free of water – both leaks and pooling.
  3. Assistance from a responsible site representative for panel cover removal, access, and keys etc.
  4. All electrical and mechanical equipment to be running under normal load patterns.
  5. All access panel covers removed where safe do so.
  6. Cubicle isolators defeated where safe to do so.
  7. Any access equipment required to reach panels will need to be provided by the client.
  8. A clear working area will be required for the inspection, it is still the client’s responsivity to remove any trip hazards and any items that may affect the line of site for collecting the images and data.
  9. If mechanical machinery is to be used to aid the thermographic survey it must be operated by a suitably trained operator and the suitable fall/harnesses etc. provided. A banksman must also be provided as and when required.
  10. As the survey will generally be undertaken during daylight hours, a single engineer will be provided. If lone working is required on the site, the client must provide a representative to accompany the engineer throughout his survey inspection.
  11. Thermographic inspectors shall have unrestricted access to the Site. Where access is limited or there are obstructions which cannot be overcome, then the survey report will reflect this. Thermographic inspectors shall not be liable for any deficiencies in the report because of poor access or the presence of an obstruction.
  12. Surveys undertaken by walking over the surface of the roof or next to water will only be undertaken under the accompaniment of a client’s representative. Safety harnesses (that are fit for purpose) must be supplied by the client and worn as required.
  13. The client will be responsible for the safe conduct of the inspection and will be responsible for all operatives and equipment in his charge.
  14. Tests may be witnessed by the contractor, the Contract Administrator (CA) and/or the Building Inspector. The contractor should liaise with all parties in advance to ensure their attendance at the prescribed time of the survey. The engineer cannot wait until witness parties arrive as this will cause delays to the survey.
  15. Any accidents, injuries or unsafe conditions on site must be notified immediately to the main contractor. Accidents and/or injuries sustained by APT engineers must be recorded and notified to the main contractor. Notification under RIDDOR must be arranged by the consultant through the main contractor, should such situations arise.
  16. Quality control and Supervision – the client shall be responsible for the site quality control to check that the subcontractors and suppliers complete the work in accordance with the contract drawing and
  17. If the client requires a site-specific RAMS for the works, notification must be sent through in writing (email) at least one week prior to the test date.
  18. Parking for a transit type van on site



There are many causes for increased temperature in electrical installations, such as  loose connections, overloaded circuits, and failing components.  By identifying these areas of heightened temperature, thermographers can identify potential issues before they lead to more significant problems.

the main advantage of infrared thermography is its ability to uncover hidden electrical faults that may not be apparent through routine testing/visual inspections.

The main reasons for temperature abnormalities are:

  1. Pinpointing Loose Connections: Loose electrical connections, often caused by vibration, can lead to resistance and increased temperatures. Thermal imaging inspections can spot these loose connections by detecting the temperature rise at the point of fault to the other connects around the faulty connection.
  2. Identifying Overloaded Circuits: Overloaded circuits generate excess heat due to the increased current flow. Infrared thermography can identify overheating circuit breakers, conductors,  and switches, to allow for targeted remedial works.
  3. Pinpoint Imbalanced Loads: Imbalanced loads in larger three-phase systems can result in phase overheating. Infrared thermography can quickly identify the phase with increased  temperature, allowing the stakeholder to balance the load and prevent further damage to the system.
  4. highlighting Failing Electrical Components: Failing components, such as motors or bearings, tend to heat up before they completely fail. Thermal imaging can detect abnormal heat patterns in these components, signaling the need for maintenance or replacement prior to failure.
  5. Reducing the chance of Electrical Fires: Overheating electrical components are one of the leading causes of electrical fires. By detecting early signs of overheating, thermal inspections can help prevent potential fire hazards and protect personnel and property.

The Advantages of Infrared Thermography in electrical Fault Detection
Infrared thermography is a non-contact method, meaning there is no need to shut down equipment or disrupt operations during inspections, resulting in lower impact to sites.

We use the latest High Definition infrared camera from FLIR. Our T640 infrared camera is a very goo camera for professional thermography with its high-definition 640 X 480 infrared detector, delivering exceptional resolution and image quality for accurate infrared surveys.

Due to the infrared cameras high pixel count, accurate readings can be taken on smaller objects at further distances due to its smaller pixel footprint (spot) size. The smaller the spot size, the more pixels the image will have across any target such as a large electrical distribution boards at a given distance. This enables the imager to make more accurate measurements, from a further distance and adds visual detail to the thermogram.

High Definition provides up to 4 times the pixel resolution of conventional Infrared cameras, making it easier to read the reports and target the  problems and know what to repair!

Working safety risk assessors, facility management companies, insurance companies and engineering maintenance managers, our thermographic survey reports have been carefully developed to satisfy strict standards ensuring that the highest quality reportage from the thermographic inspection.

All electrical thermographic Survey reports are reviewed and approved by Level 3 trained Thermographers and are structured as follows:

  1. Introduction and Report Summary – This provides detail on the electrical thermal inspection, as well as a clear and concise summary of the overall findings.
  2. Main Fault Report Pages – Where faults and/or anomalies are identified, an individual report page is produced providing a description of the fault, its severity and recommended remedial action.
  3. Appendices – These pages provide a checklist and images of every asset inspected during the survey. This provides an auditable record of what was inspected, together with equipment health at the time of the survey.
  4. Trend Analysis – Once the baseline has been set, you can use thermal trending inspections to compare how temperature is distributed in the same components over time, i.e. every 12 month’s.  This can help  detect declining performance of components over time, so that you can hopefully schedule downtime maintenance before the failure of equipment and system shutdown.

No, it’s not advisable to perform an electrical thermal imaging survey yourself, unless you have the proper training, certification, and equipment. Electrical thermal imaging surveys are complex and require a lot of planning, preparation, communication, safety, and data collection. You also need to know how to analyse the thermal images properly and identify the faults or defects in the electrical system or equipment. A qualified and certified thermographer can do this job more safely, efficiently, and accurately.


It’s worth noting that looking at online videos, are not substitutes for professional thermal imaging training and certification. You can also contact a reputable infrared inspection company to perform the survey for you. They will have the experience and expertise to provide you with a reliable and comprehensive report of your electrical system’s condition as well as recording ongoing trend analysis.

A qualified thermographer is someone who has the proper training, certification, and equipment to perform electrical infrared surveys. There are different levels of thermography certification, depending on the complexity and scope of the survey. You can find a qualified thermographer by looking for reputable trainers or companies that offer thermography services.


There are many sources that can help you find a qualified thermographer. The website of the International Association of Certified Thermographers (IACT), which maintains strict guidelines for the training and certification of thermographers and technicians. You can use their online directory to find a thermographer near you, based on the area of thermography you are interested in.

The three main certifications for thermographers are as follows:

  • Level 1 thermography certification: This is the starting point for those who are new to electrical thermography or need to refresh their skills. It covers the basics of thermal imaging, infrared theory, and common applications.
  • Level 2 thermography certification: This is for electrical thermographers who have some experience and want to advance their knowledge and skills. It covers more advanced topics, such as calibration, equipment operation, data analysis, and IR windows and is usually preferred for the majority of surveys.
  • Level 3 thermography certification: This is for thermographers who want to become experts and leaders in the field. It covers topics such as program management, standards development, quality assurance, and training.

We carry out all our electrical thermal imaging surveys with Level 3 thermographers.

In some instances, the electrical equipment being inspected may pose a safety risk due to the extent of the temperature rise. NETA (International Electrical Testing Association) guidelines dictate immediate action is required when the difference in temperature between similar electrical components under similar loads exceeds 15 °C (27 °F) or when the difference in temperature between an electrical component and the ambient air temperatures exceeds 40 °C (72 °F), this is called a ”red alert” in **electrical thermal imaging**.

High quality thermal imaging cameras can measure a wide temperature range from -40 degrees to up to 550 degrees Celsius, which translates to up to 1022 F. This helps to detect the slightest temperature changes, which can help thermographers quickly spot issues within individual electrical components. The integrated thermal image sensor in each camera displays the exact location of the concerning hot spots within electrical systems so they can be identified and replaced. 

Thermal sensitivity – This defines the minimum temperature difference the camera can detect and is extremely important in building surveys due to the small temperature differences we are often looking for. The smaller the number the better for all types of electrical surveys:

  • <30mK (0.03 degC) – high end professional
  • <40mK (0.04 degC) – professional
  • <50mK (0.05 degC) – mid-range
  • >60mK (0.06 degC) -not suitable for building surveys


Detector size – This defines the number of pixels in the image. The bigger the number the better.

  • 640×480 (professional – 300,000 pixels per image)
  • > 320×240 (mid-range – over 75,000 pixels per image)
  • < 320×240 (entry level/hobbyist – under 75,000 pixels per image)


Lens angle – Like normal cameras, thermal imaging lenses from wide angle to telephoto are available.

  • 45deg wide angle – with a professional camera (640×480) a wide-angle lens is useful for most building applications such as BREEAM inspections, providing enough resolution for whole building elevations.
  • 35deg slightly wide angle – a good compromise on mid-range cameras providing a medium view with acceptable resolution.
  • 25deg standard lens – may be required with smaller detectors to provide enough resolution but provided a restricted view of buildings or rooms leading to reports which provide a limited overview of the building etc.

We spend much a large amount of time on our reportage, that’s why it’s one of the best in the industry, this is obviously a part of the service which is off site and clients don’t see. Whilst we may draw initial conclusions on site, which may need more investigation; usually, our final conclusions and report will only be finalised after all the data has been studied. It’s our ongoing aim to provide every report that is clear and easy to reference.

If you require a electrical thermal imaging inspection our professional and certified Level 3 Thermographer’s will carry out your thermographic Inspections for all necessary standards and current regulations.

All we need are a few details such as the building address and the number of electrical installations within the building. Floor plans and would also be helpful to allow us to orientate ourselves during the inspection. We will also send across our informative checklist to help you prepare for the thermal survey.

Please contact us for more information

If you would like to contact us for more information on our thermal imaging services, please contact us on 01525 303905 or email us at info@aptsoundtesting.co.uk