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Thermographic inspections: preventing electrical failures
In industrial environments, substations, and medium- and low-voltage electrical systems, operational reliability is directly linked to the health of the equipment. Electrical faults do not always give visible signs, but they can be detected in time with the use of predictive technologies, and thermographic inspection is one of the most efficient in this process.
Thermography allows the identification of abnormal heating points, which may indicate faults, overloads, loose connections, or component wear. In this article, you will understand how thermographic inspection works, its application in electrical panels and distribution systems, and how it contributes to the safety, efficiency, and cost savings of projects.
What is thermographic inspection?
Thermographic inspection is a predictive maintenance method that uses infrared cameras to detect temperature variations in electrical equipment and systems.
These cameras capture the heat radiated by the components, transforming it into thermal images that highlight hot spots. These spots are indicative of anomalies that, if left untreated, can lead to failures, short circuits, equipment burnout, and even fires.
Difference between thermography and other electrical inspection methods
The main difference between thermography and other inspection methods is that it is non-intrusive, meaning it can be performed with equipment in operation, without the need to shut it down.
Other methods, such as resistance measurements or continuity tests, generally require shutting down the system and direct intervention, and they do not detect thermal problems arising from poor connections, overload, or phase imbalance—which thermography easily visualizes.
What is thermographic analysis used for?
The main objective of thermographic inspection is to identify points of abnormal heating that indicate:
Equipment overload
Loose or rusted connections
Phase imbalance
Components at the end of their useful life.
Insulation problems
It allows for preventative interventions, before a failure becomes a critical problem.
Where can thermographic inspection be applied?
Thermography has wide application in different sectors and equipment:
Low and medium voltage switchboards
Motor Control Centers (MCCs)
Medium voltage cubicles
Busbars (shielded or conventional)
Circuit breakers, transformers and disconnect switches
Power distribution systems
Industrial equipment, motors, inverters and generators
Air conditioning and refrigeration (HVAC) systems
Building and commercial installations
Inspection of electrical switchboards and distribution panels.
When applied to electrical panels and distribution boards, thermography is a fundamental tool for ensuring safety and operational continuity.
In systems such as medium-voltage switchgear, MCCs , and main distribution boards , it is possible to accurately identify problems such as:
Overheating in connections, terminals and busbars.
Oxidation on terminals and screws
Load imbalance between phases
Defects in protective devices (circuit breakers, relays, surge protection devices)
These analyses allow for planned corrective maintenance, preventing unexpected shutdowns, major damage, or accidents.
Main problems detectable with thermography
Loose or poorly tightened connections
Oxidation or corrosion in terminals
Overload in circuits
Phase imbalance
Internal defects in circuit breakers and relays
Insulation problems in busbars or cables.
Overheating points due to natural wear and tear of components.
Benefits of thermographic inspection
Cost reduction through corrective maintenance: Allows scheduling maintenance at the right time, avoiding higher costs due to unexpected failures.
Fire and accident prevention: By detecting abnormal heating, one of the greatest fire risks in electrical systems is eliminated.
Extending the lifespan of equipment: Predictive maintenance helps equipment operate within optimal parameters for longer.
Energy saving: Poor connections, oxidation, and overloads generate energy losses. Correcting these issues reduces consumption.
Better return on investment (ROI): The cost of an inspection is much lower than the consequences of an unexpected shutdown, equipment burnout, or production loss.
Recommended frequency of inspections
According to best market practices and technical standards, thermographic inspection should be performed at least once a year.
However, for critical installations, such as substations, power plants, data centers, or industrial processes that cannot be interrupted, the recommendation is to carry out inspections every six months or even every three months.
Furthermore, additional inspections are recommended after renovations, expansions, or whenever there are significant changes in the system load.
Applicable technical standards
Thermographic inspection follows guidelines from the main technical standards and norms, such as:
NBR 15424: Non-destructive testing – Thermography – Terminology;
NBR 15763: Non-destructive testing – Thermography – Criteria for defining inspection frequency in electrical power systems;
NBR 15866: Non-destructive testing — Thermography — Methodology for evaluating the operating temperature of equipment in electrical systems.
These standards reinforce the importance of inspection as a factor in safety, reliability, and good operational practices.
Thermographic inspection is one of the most efficient tools for ensuring the safety, efficiency, and continuity of electrical systems.
Whether in cubicles, MCCs, distribution panels, or busbar systems, thermal analysis allows you to identify and correct problems before they become serious failures.
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