Thermographic Inspection of Electrical and Mechanical Plant Under Load

An electrical connection that is failing gets hot long before it fails. Infrared thermography finds those developing faults while the plant is running and before anything trips, which is the difference between a scheduled repair and an unplanned outage. itmad provides thermographic inspection and thermal imaging surveys of electrical and mechanical plant under load, using calibrated instruments and qualified thermographers. Loose or corroded connections are the most common electrical finding and a common cause of switchboard fires. itmad operates across the Middle East, Asia and Europe. Last reviewed: October 2026.

Why it must be done under load

Thermography detects heat generated by resistance, and resistance produces heat only when current flows. A survey on de-energised or lightly loaded equipment finds nothing, because a defect that would show at full load produces no thermal signature at 20% load. Surveys are therefore scheduled when plant is running at representative load, and the load at the time of survey is recorded with each finding: a temperature rise measured at 40% load means something quite different from the same rise at full load, and a report that omits it cannot be interpreted correctly.

What itmad surveys

In switchgear and distribution boards, the survey covers busbars, circuit breakers, contactors, fuses, terminations and connections across LV and HV distribution, where a differential of 10°C above a reference component indicates a finding that needs action, and a differential above 40°C indicates immediate risk. Transformers are surveyed at the bushings, terminations, tap changers, cooling systems and radiator flow, as well as tank and oil temperature distribution, and motors and drives at the bearings, windings, couplings, terminal boxes and variable speed drives, where the thermal pattern indicates mechanical as well as electrical condition.

Cable joints, glands, terminations and cable runs are included, among them connections that overheat because the conductor size or torque was wrong at installation. In mechanical plant, bearings, couplings, pumps, gearboxes, conveyors and steam traps are surveyed, since friction or blockage produces a thermal signature before mechanical failure, and in process and building services the survey assesses insulation condition on vessels and pipework, refractory integrity, and heat loss across building envelopes.

What the survey finds

Loose, corroded or under-torqued connections; load imbalance across phases; overloaded circuits and undersized conductors; failing contacts, contactors and circuit breakers; bearing degradation before it becomes audible; blocked cooling paths and failed cooling fans; damaged or missing insulation; and failed steam traps passing to drain.

Reporting and severity grading

Each finding is reported with the thermal image and a matching visual photograph, the measured temperature at the anomaly, the reference temperature of a comparable component under the same conditions, and the load at the time of the survey. Each is graded for severity: immediate action required, correct at the next planned shutdown, or monitor. A report that grades everything urgent gets ignored, and severity grading is what makes findings actionable.

Why organisations commission surveys

Many property insurers specify periodic thermographic surveys of electrical installations as a condition of cover. Others commission them for predictive maintenance programmes that find faults between planned shutdowns, for verification after installation, modification or maintenance work, for investigation following unexplained tripping or equipment failure, as a condition assessment before acquiring or leasing a facility, and to establish a thermal baseline for future comparison.

Survey intervals

An annual survey is the common baseline for electrical distribution, shortened to six-monthly for critical installations, high-duty-cycle plant, or equipment in hot, dusty or corrosive environments. Where an insurer sets the interval, that governs, and surveys are also carried out after any significant modification to the installation.

Safe access

Thermography needs a line of sight to the component, which on enclosed switchgear means either opening panels under load or using installed infrared viewing windows. Opening live panels carries arc flash risk and is carried out only where the client's permit system allows it and with appropriate controls in place. Where it is not permitted, itmad says so and identifies what viewing windows would be needed to survey that equipment safely.

Scheduling and personnel

Surveys are carried out at industrial facilities, commercial buildings, substations and offshore installations. Because they must be conducted under load, attendance is scheduled to match operating conditions and not office hours, including night and weekend working where that is when the plant runs. Qualified thermographers carry out the work using calibrated instruments, and instrument calibration traceability is provided in every report.

Frequently asked questions

What is thermographic inspection and what does it find?

It uses calibrated infrared cameras to detect heat generated by electrical resistance and mechanical friction in plant running under load. It finds loose or corroded connections, load imbalance, overloaded circuits, failing contacts, bearing degradation, blocked cooling paths and failed steam traps before they cause an outage or fire.

Why must thermal imaging surveys be done under load?

Resistance produces heat only when current flows, so a survey on de-energised or lightly loaded equipment finds nothing. The load at the time of survey is recorded with each finding, because a temperature rise at 40% load means something quite different from the same rise at full load.

What equipment is surveyed?

Switchgear and distribution boards, transformers, motors and drives, cables and terminations, mechanical plant such as bearings, pumps and steam traps, and process and building services such as insulation and building envelopes. Each is surveyed under representative load.

How often should surveys be carried out?

Annually is the common baseline for electrical distribution, and six-monthly for critical installations, high-duty-cycle plant or equipment in hot, dusty or corrosive environments. Where an insurer sets the interval, that governs.

Do insurers require thermographic surveys?

Many property insurers specify periodic thermographic surveys of electrical installations as a condition of cover. itmad issues reports with thermal and visual images, measured and reference temperatures, and severity grading for each finding.

How are findings graded?

As immediate action required, correct at the next planned shutdown, or monitor. A temperature differential of 10°C above a reference component indicates a finding needing action, and above 40°C indicates immediate risk.