Inside an Infrared Survey: Overhead Distribution Line Report
This is an anonymized sample of a real Invizions infrared inspection report for an electric cooperative's overhead distribution system. It shows exactly how we document thermal exceptions, assign objective NETA priority ratings, and give you a clear, prioritized repair roadmap.
Electric Cooperative — OhioJanuary 2025Level II Certified Thermographer
Report Foreword
Every Invizions report provides complete documentation of the exceptions — abnormally warm or cool equipment — found during the infrared inspection of your equipment. It uses a variety of data and ratings to help prioritize your repairs and give you the greatest return from your maintenance efforts.
Inspections are performed and prepared by a Certified Infrared Thermographer. To earn this certification, the thermographer must complete coursework and pass examinations administered by the Infraspection Institute.
This report fully meets the requirements of the Infraspection Institute's “Guidelines for Infrared Inspection of Electrical and Mechanical Systems.” It also references, incorporates, and exceeds all other published guidelines and standards pertaining to the infrared inspection of electrical and mechanical systems, and is conducted to NETA (National Electrical Testing Association) standards.
How Findings Are Prioritized
Temperature Severity Ratings are objective and based on temperatures measured by the thermographer. The exception temperature is compared against a reference temperature on a similar healthy component to produce a delta-T (temperature rise), which maps to the NETA Priority Criteria for Electrical & Mechanical Exceptions:
10–18°F rise
Possible deficiency; warrants investigation.
218–36°F rise
Probable deficiency; repair as time permits.
336–72°F rise
Monitor continuously until corrective measures can be accomplished.
472°F & above rise
Major discrepancy; repair immediately.
Inspection Summary
Over a one-day survey, the thermographer scanned overhead connections, cut-out switches, and regulator banks across 22 distribution locations. The majority tested normal (“OK”); five thermal exceptions were identified and documented for corrective action.
22
Locations inspected
5
Exceptions found
1
Day on site
Documented Thermal Exceptions
Each exception is documented with a paired visual control photo and thermal infrared image, the measured temperatures, the calculated delta-T, and a specific corrective recommendation.
Representative visual control photoRepresentative thermal infrared image
1
State Route 589
C-phase bypass switch on device 4515.
Priority 3
Findings
Suspect possible poor switch connection.
Recommendation
Disassemble, inspect, clean switch connection and check for proper tension.
NETA Priority Rating
Monitor continuously until corrective measures can be accomplished.
Exception Temp (Area 1)87°F
Reference Temp (Area 2)44°F
Delta-T43°F
2
State Route 55
Bottom switch connection on north phase cut-out switch on pole 82947.
Priority 3
Findings
Suspect possible poor switch connection.
Recommendation
Disassemble, inspect, clean switch connection and check for proper tension.
NETA Priority Rating
Monitor continuously until corrective measures can be accomplished.
Exception Temp (Area 1)71°F
Reference Temp (Area 2)25°F
Delta-T46°F
3
Pisgah Road
Center phase lightning arrestor on pole 49096.
Priority 2
Findings
Suspect possible damaged and/or cracked lightning arrestor.
Recommendation
Inspect for cause of heating and correct as required.
NETA Priority Rating
Indicates probable deficiency; repair as time permits.
Exception Temp (Area 1)49°F
Reference Temp (Area 2)29°F
Delta-T20°F
4
Neil Pearson Road
Top C-phase cut-out switch on middle cross arm on east side of pole 18824.
Priority 3
Findings
Suspect possible poor switch connection.
Recommendation
Disassemble, inspect, clean switch connection and check for proper tension.
NETA Priority Rating
Monitor continuously until corrective measures can be accomplished.
Exception Temp (Area 1)82°F
Reference Temp (Area 2)32°F
Delta-T50°F
5
Johnston Road
Bottom switch connection on north phase cut-out switch on pole 36204.
Priority 2
Findings
Suspect possible poor switch connection.
Recommendation
Disassemble, inspect, clean switch connection and check for proper tension.
NETA Priority Rating
Indicates probable deficiency; repair as time permits.
Exception Temp (Area 1)80°F
Reference Temp (Area 2)50°F
Delta-T30°F
Equipment & Data Log
Certified Thermographer
Level I/II Certified (Infraspection Institute)
Camera Manufacturer
FLIR
Model
T400
Software
FLIR Quick Report 1.2
Accuracy
+/- 2%
Calibration
Annual
Wave Band
Long Wave (8–14 µm)
Lens
FOL18
Ambient Air Temp.
10–38°F
Inspection Type
Industrial Electrical / Mechanical
Want a Report Like This for Your System?
Invizions performs infrared surveys of overhead distribution lines, substations, and industrial electrical systems — with clear, NETA-rated documentation you can act on.
