EN
Thermal Camera Inspection
Thermographic surveys of panels, transformers and mechanical systems: hidden hot-spot detection with reports and maintenance priority.
Thermal camera inspection is mapping the contactless surface temperatures of electrical connection points, panel and equipment surfaces and mechanical systems with infrared cameras; overheating zones (hot-spots) are classified before turning into faults and fire. A loosened busbar joint, an unbalanced phase, a clogged bearing — all leave a thermal signature before visible symptoms, making this measurement the most efficient input of predictive maintenance programmes.
Application Areas and Criteria
- Electrical installations: Phase-to-phase / phase-to-neutral comparison on panels, busbars, fuses-contactors, cable heads, transformer bushings and MV cells. Evaluation relies on temperature difference (ΔT) rather than absolute temperature; typical acceptance band is suspicious above 10-20°C depending on reference material and ambient (FGK guideline approaches).
- Mechanical equipment: Friction heat on motor bearings, gearboxes, couplings, bearings, brake pads and conveyor drums; insulation and leak detection on steam-condensate lines.
- Building-facility: Façade insulation defects, moisture-thermal bridges, boiler house surface temperatures and (if any) PV string monitoring.
- Fire precursors: Dust-accumulating areas, oily equipment zones and loaded extension lines enter the scan scope.
Measurement Discipline
Correct thermography requires camera resolution-wavelength control, emissite setting, reflected temperature compensation, atmospheric correction and angle discipline. Readings are taken under load (near full capacity) and in still air where possible; reflective surfaces are verified with contact probes or paint spray. Each point records position, conjugate reference and temperature value on the IR image; results trend against previous surveys. Operator competence (e.g. ISO 18436-7 class) and calibration traceability appear in the report.
Legislation and Standards
Although thermography is not itself a mandatory periodic control, it is tied into the legislation system as a standard preventive maintenance tool under fire risk management, electrical installation maintenance duties (Law No. 6331 and regulations) and insurer demands. Technical reference: the FGK/VDW 0533 guideline for thermography of electrical installations (with IEC-based practice rules), personnel competence ISO 18436-7, and ISO/IEC 17025 calibration traceability. In critical facilities the scan period is set by load profile and history (annually; six-monthly on large panels in practice).
Risks and Operator Recommendations
The leading source of false comfort in thermography is scanning at light (low-current) load: a loosened joint hidden in moderate current heats proportionally at peak and escapes. Therefore measurements must be scheduled under real production load. Contamination and paint lower emissivity; a wrong emissite value misreads temperature by several degrees. Findings must be linked to maintenance decisions: same-shift isolation (cut-backup) for critical hot-spots, planned shutdown repair for major, rescan calendar for monitoring. Trend data serves as the justification of panel-based maintenance budgets.
Outcome
At the end of the scan a signed thermal survey report with temperature maps, ΔT values and maintenance priority table is issued. Thermography is the shared input of our Periodic Inspection of Installations and Tests and Analyses services. See the Earthing Inspection page and contact us for your programme.
FAQ on Thermal Camera Inspection
LV and MV electrical installations: panel-terminal-bus-transformer-outgoing-power cable transitions, capacitor banks, motor-gearbox-bearing, drive-VFD-inverter cooling, battery-pole-joint groups, MV cells-cable-heads; on the mechanical side steam-hot oil-pipe insulation-leak, furnace-dryer surface, heat exchanger blockage, boiler wall-combustion; plus building facade-insulation-water-leak-damp. The scan serves energy efficiency, fire and fault prevention.
A thermal anomaly appears only with current or heat duty: a loose-contact-joint heats through contact-resistance I²R only under load current, and an empty panel hides nothing to catch. Therefore scanning runs at operating load (ideally 40-50 % occupancy or above); in critical facilities the peak-load moment (seasonal-campaign) is the best window. Before-after repair-verification scans (thermal control) also measure how effective the correction was.
Interpretation has two references: absolute temperature and phase-to-phase or symmetric-part difference delta-T. Practice (for instance the EN 13187 approach for buildings; for electrical, IEEE C57, IEC 60099/EPRI criteria) puts an inter-phase delta-T above roughly 10-20 °C in the warning-critical band, with equipment insulation class limits as the ceiling (motor-bearing-transformer oil). Low-emissivity bright metallic surfaces (tape-painted-measurement approach), ambient air and wind are loaded into the reading; emissivity setting and reference sensor verification correct it.
The report carries thermal photo-visible paired images, spot temperature value, delta-T, criticality classification (urgent-short planned) and a suggestion set (retorque-replacement-cleaning-cooling), located with equipment-sketch-position (panel-breaker-line). Urgent: planned de-energised retorque (LOTO safe); loose contact, hot cable head, fan-brake-bearing overheat, insulation gap-pipe leak. Finding follow-up (previous-next scan) tracks the trend and the energy-fire-fault triangle is managed. Period: annual scan plus interim checks in critical-heavy production sites; all records enter the OHS-energy file.