What it is and when you need it
Infrared thermography is a non-contact inspection that measures the temperature of connections, contacts, busbars and equipment while they are in service. Its purpose is to find hot spots: loose joints, poorly installed terminals, worn contacts or overloaded circuits that run hotter than their neighbors carrying the same current. Almost all connection failures start this way, weeks or months before a terminal burns or an arc occurs.
It is the fastest predictive maintenance tool: in one working day you can survey panels, switchgear, transformers and yards without de-energizing anything. It tells your maintenance team where to focus the next outage.
We recommend it in these cases:
- Routine maintenance, once or twice a year, in substations and in the panels of industrial, commercial and utility plants.
- After an installation or extension, once the system takes load, to confirm that the new connections are sound.
- Before a scheduled outage, to arrive with the list of what to tighten, clean or replace.
- When there are symptoms: burning smell, discolored terminals, trips with no clear cause or a fuse that blows without an apparent overload.
- At an insurer’s request or as part of a maintenance program based on NFPA 70B.
It is part of our testing and commissioning service.
What is included
- Thermographic survey of the agreed equipment: substation (transformers, bushings, circuit breakers, disconnectors, surge arresters, clamps and connectors), medium voltage switchgear, distribution boards, motor control centers (MCCs) and low voltage panels, capacitor banks, busbars and cable terminations.
- Thermography of photovoltaic modules in the DC field of solar plants, from the ground and by drone.
- Load measurement of each inspected circuit, so severity is interpreted with the real current at the time.
- Classification of each finding by temperature rise (ΔT) against a similar component and against ambient, using the ANSI/NETA criteria, with an action priority.
- Thermal and visible image of each finding, so your staff can locate it without doubt.
- Immediate notice of any serious condition, without waiting for the report.
- Confirmation tests when agreed: contact resistance on the suspect breaker or joint, and a new thermographic scan under load after the repair.
How we work
- Planning. We review with you the equipment list, the single-line diagrams and the peak-load hours. We agree which panels are opened, which have infrared windows and which are inspected from the outside.
- Safety. Opening an energized panel exposes people to arc flash risk. We coordinate with your staff the opening of doors and covers, the right protective equipment and the distances according to the installation’s risk assessment; where it exists, we rely on the arc flash study.
- Inspection. We record emissivity, reflected temperature, ambient temperature, wind and load at each point. We compare each connection with its twins on the other phases, which is the most reliable comparison because they share material and current.
- Analysis. We separate true hot spots from reflections and from low-emissivity surfaces, such as polished copper, that fool the camera. Each finding gets its probable cause and its priority.
- Report. We deliver the report with findings ordered by priority and the list of equipment inspected with no findings.
What we need from you
- The list of equipment or panels to inspect and their location, or the installation’s single-line diagram.
- Equipment running at its normal load on inspection day; if the plant works in shifts, the peak-load hours.
- A person from your operations to accompany the survey, open the panels and know the circuits.
- The work permits and safety rules of your site.
- Earlier thermography reports, if any, to compare and see the trend.
Standards
We work with the recognized references for electrical thermography:
- ANSI/NETA MTS and ATS, which provide the table of suggested actions by temperature rise, against a similar component and against ambient.
- NFPA 70B, which since its 2023 edition is a standard for electrical equipment maintenance and sets the frequency of thermographic inspection according to equipment condition, besides requiring that the temperature rise of each finding be documented.
- ASTM E1934, guide for examining electrical and mechanical equipment with infrared thermography.
- ISO 18434-1, general procedures for thermography in condition monitoring.
The report always states which severity criterion was applied. A ΔT does not predict how long is left before a failure: it sets a priority, and every hot spot is investigated and corrected.
What you receive
- A report with each finding: equipment, location, thermal and visible image, temperatures, ΔT, load, criterion, probable cause and recommended action.
- An executive summary with findings ordered by priority, to plan the intervention.
- The list of equipment inspected with no findings.
- The recorded measurement conditions, so the next inspection can be compared with this one.
Why Tiza Group
- Our team works in medium, high and extra-high voltage substations and in industrial plants: it understands what it sees in the image and what it means for operation.
- We do not stop at the picture. We run the tests that confirm the cause, such as contact resistance, and verify the repair under load.
- Clear reports, written so your maintenance staff knows what to do and in what order.
Field work is done in Colombia, or elsewhere on request. Contact us to plan your thermographic survey.