Thermographic Inspection — In Brief
Thermographic inspection (infrared inspection) is a preventive maintenance method that detects abnormal heating in electrical installations and mechanical equipment without contact using a thermal camera (IR camera). Problems such as an overheating connection, a loose screw, an unbalanced load, or a contactor fault reveal themselves through a temperature rise before they are visible to the human eye. Thermographic inspection is carried out in accordance with NETA MTS-2019, ASTM E1934, ISO 18434-1 standards and provides 70–80% fault prevention in electrical installations. Many fire insurance policies require an annual thermographic report for companies.
Why Does Thermography Save Lives?
An electrical connection normally operates with a ≤ 5°C difference from its surroundings. If a screw loosens or the connection corrodes, the current encounters resistance and produces I²R loss (Joule heating). When this waste heat rises to 30–50°C, it begins to melt insulation and start a fire.
Thanks to thermography:
- Pre-fire detection (when the temperature is in the 50–80°C range)
- Inspection without entering inside a closed panel
- Operation under load (no outage required)
- Presentation to management with a color visual report
Thermal Cameras Used
| Brand | Suggested Model | Resolution | Temperature range | Price (TR 2026) |
|---|---|---|---|---|
| FLIR | E96 / T-series | 640×480 | −20 to +1500°C | 85,000–180,000 TL |
| Fluke | TiX580 | 640×480 | −20 to +1200°C | 90,000–160,000 TL |
| Testo | 875 / 890 | 320×240 / 640×480 | −20 to +1200°C | 60,000–120,000 TL |
| Hikmicro | M30 | 384×288 | −20 to +650°C | 25,000–40,000 TL |
| Bosch | GTC 600 C | 256×192 | −10 to +600°C | 18,000–30,000 TL |
For professional use, at minimum 320×240 resolution, 9 Hz refresh rate, and ±2°C accuracy are required.
Thermographic Inspection Process in 7 Steps
Step 1: Pre-Preparation and Briefing
- Approval from facility management (if panels will be opened)
- Check the single-line diagram and panel labels
- Verify load condition (must be at least 40% loaded — abnormalities are not seen below this level)
- Environmental conditions: room temperature, air circulation, sunlight reflection
Step 2: Setting Up the Thermal Camera
- Emissivity: 0.30 for copper busbar, 0.20 for stainless steel, 0.95 for plastic
- Reflected temperature: ambient temperature + 2°C
- Temperature range: automatic or −20 to +250°C
- Image mode: standard palette (Rainbow or Iron)
Step 3: Opening the Panel and Safety
- Visual inspection before opening the panel cover (models with IR-transmissive glass should be preferred)
- If the panel cover will be opened, PPE: insulating gloves (Class 2), face shield, arc-flash clothing
- LOTO is NOT REQUIRED (inspection is performed under load)
Step 4: Systematic Scanning
Points to be examined in order:
-
Main incoming breaker (ACB/MCCB)
- Incoming and outgoing bushing terminals
- Equal temperature across all 3 phases (max ΔT = 3°C)
-
Busbar system
- Connection points on phase busbars
- Busbar-bolt contacts
- Busbar-bushing junction points
-
Outgoing breakers (one by one)
- Each MCCB / MCB
- Terminal connections of outgoing cables
-
Contactors
- Main contact points (3 phases)
- Auxiliary contacts
- Coil temperature (max 100°C is acceptable)
-
Thermal magnetic relays
- Connection sides
-
Fuse holders
- Connection points on the fuse
- Seat and clip contacts
-
Compensation capacitors
- Capacitor body temperature (max 70°C)
- Connection terminals
- Switching contactors
-
Cable connections
- Lug and terminal block connection points
- Line entries (cable gland)
Step 5: ΔT Analysis and Classification
NETA MTS-2019 standard:
| ΔT (relative to a reference under the same load) | Class | Action |
|---|---|---|
| 1–10°C | Green | Monitor, repeat at the next inspection |
| 11–20°C | Yellow | Planned maintenance — within 1 month |
| 21–40°C | Orange | Urgent maintenance — within 1 week |
| > 40°C | Red | REPAIR IMMEDIATELY — de-energize the system |
ΔT calculation method: Compare the temperature at the same point on the 3 phases within the same panel. Example: Phase R 65°C, Phase S 35°C, Phase T 38°C → ΔT on Phase R = 27°C → ORANGE
Step 6: Documentation
For each thermal image:
- Image ID and location (e.g., P1-MCCB-Outgoing-R-phase)
- Date and time
- Ambient temperature
- Load condition (% loading)
- Thermal image (jpeg/IR format)
- Visual camera photo from the same position
- Maximum temperature point
- Calculated ΔT
- Classification (green/yellow/orange/red)
Step 7: Report Preparation and Recommendations
Thermographic Report Structure:
- Facility information and load condition
- Equipment used and calibration date
- Summary of findings (distribution of green/yellow/orange/red)
- Photo-documented detail page for each finding
- Recommended action plan
- Next inspection date (recommended)
- Signature of the certified thermographer
Acceptance Criteria and Typical Abnormalities
| Finding | Interpretation |
|---|---|
| Loose connection on one phase | One phase hotter (ΔT 15–40°C) |
| Equally high temperature on all phases | Overloading (continuously above 80%) |
| High fuse holder temperature | Fuse seat loose or thermally fatigued |
| Hot contactor main contact | Contacts corroded/burnt — replace contactor |
| High busbar temperature | High-current busbar — busbar upgrade required |
| Capacitor body 80°C+ | Must be replaced before explosion |
Certification Levels (ISO 18436-7)
- Level 1 (Basic): Use of the camera, interpretation of simple images
- Level 2 (Advanced): ΔT analysis, abnormality classification, report writing
- Level 3 (Expert): Industry standard development, program management
For a professional thermographic report, a Level 2+ certified specialist is required.
Thermographic Inspection Frequency
| Facility | Recommended Frequency |
|---|---|
| Data center | Once every 3 months |
| Hospital / Critical | Once every 6 months |
| Industrial facility | Once a year |
| Commercial workplace | Once a year |
| Residential / Apartment | Once a year (main panel) |
DOA Enerji Thermographic Inspection Service
DOA Enerji performs the annual thermographic inspection of your electrical installation with FLIR T-series and Fluke TiX580 cameras, supported by our ISO 18436-7 Level 2 certified thermographers. We provide a color, detailed PDF report, an insurance-company-format printout, and an annual periodic maintenance contract.
Frequently Asked Questions
Is our photo camera the same as a thermal camera?
No. A normal camera records visible light (380–700 nm), while a thermal camera records infrared radiation (7–14 µm) to produce a temperature map. A thermal camera provides images even in the dark.
Can thermography be performed when the facility is shut down?
No. It must be under at least 40% load. When idle or under low load, connection resistances do not generate heat and findings disappear.
Is a thermography report mandatory?
It is not legally required, but many companies with fire insurance policies require an annual thermographic report. It is strongly recommended for facility safety and regular business continuity.
Can thermography be done while the panel cover is closed?
If modern panels have IR-transmissive glass compartments (IR window), yes. Otherwise, authorized personnel opens the cover, the thermographer performs a quick scan, and it is closed. The cover is not kept open for long to avoid disrupting airflow.
What should I do if I see high temperature on a single phase?
High temperature on one phase indicates a loose connection, corroded contact, or burnt insulation. Urgent planned maintenance is required; connection screws should be checked with torque and, if necessary, the lug should be replaced. If left unattended, it may lead to a fire.