When Sound Meets Heat
How One Grid Operator Combined Acoustic and Thermal Imaging to Make Better Maintenance Decisions
Seeking a more objective way to assess asset condition and prioritize maintenance decisions with greater confidence, a large grid operator launched a pilot across four substations using FLIR acoustic and thermal technologies.
By combining partial discharge detection with thermal imaging, maintenance teams could evaluate findings in context instead of relying on a single indicator.
01 Avoid Unnecessary Maintenance
In one case, recurring partial discharge activity was detected during periods of high humidity and fog. Thermal imaging showed normal operating conditions, and the asset consistently returned to baseline after environmental conditions changed.
The issue was classified as low risk, avoiding unnecessary maintenance and allowing resources to remain focused elsewhere.
By monitoring HV-equipment continuously with thermal imaging cameras, costly breakdowns can be avoided.
02 IDENTIFY A DEFECT EARLY Maintenance
In another case, strong localized partial discharge activity coincided with a thermal hotspot. The acoustic and thermal evidence pointed to a developing defect requiring intervention.
The asset was prioritized for replacement during a planned outage, reducing the risk of an unexpected failure.
potential unplanned outages prevented
unnecessary component replacements avoided
of findings classified as “Safely Ignore”
of findings required action
The pilot demonstrated how combining acoustic partial discharge detection and thermal imaging can help operators make more confident maintenance decisions.
By distinguishing between benign conditions and developing defects, the solution helped reduce uncertainty, improve maintenance prioritization, and support grid reliability.
As the pilot customer puts it:
“The greatest value often comes from knowing with confidence that no action is required. Eliminating uncertainty helps maintenance teams focus attention and resources where they are needed most.”
Acoustic & Thermal Imaging for Hazardous Locations
