A routine infrared thermography inspection at a Dar es Salaam manufacturing plant revealed a critical 167.1 deg C cable-gland hot spot on a 1500 kVA transformer, allowing the facility to plan repairs before the defect became an unplanned outage.
Key Insights
- A 167.1 deg C cable-gland hot spot was detected while the plant remained operational.
- The finding was far above the 90 deg C safe operating limit for XLPE insulation.
- Controlled load reduction and a planned outage converted the defect into a scheduled repair.
- The repair was completed safely in 8 hours with zero unplanned downtime and zero injuries.
In February 2026, production at a two-year-old manufacturing plant in Dar es Salaam was running at full capacity to meet tight deadlines. On the surface, everything appeared normal. There was no obvious sign that a serious problem was developing inside one of the factory's critical electrical assets.
Seeing the Unseen
The Technical & Engineering Solutions (TES) condition monitoring team arrived on site, secured the required work permit, and carried out a routine infrared thermography inspection on the plant's main 1500 kVA transformer.
Using a high-resolution Fluke Ti480 PRO thermal imager, the team scanned the 400 Vac, 500 mm2 secondary-side cables while the facility remained operational under normal load. No shutdown was required.
During the inspection, a severe thermal anomaly was detected at one of the cable glands. The hot spot measured 167.1 deg C, far above the stated 90 deg C safe operating limit for the XLPE insulation. This indicated a serious developing condition that required immediate attention.
From Hidden Risk to Planned Action
TES immediately alerted facility management to the abnormal temperature and the associated risk of insulation failure, electrical fault, and equipment damage.
Instead of allowing the defect to continue developing toward an unplanned failure, TES recommended an interim action plan:
- Controlled load reduction: Production load was temporarily reduced to lower thermal stress and keep the affected area within a safer operating range.
- Planned outage: A safe, controlled de-energization of the transformer was scheduled 48 hours later so the affected area could be inspected and repaired properly.
When the cable-gland protection shroud was removed during maintenance, the severity of the condition became clear. The outer cable insulation was burnt, and the XLPE insulation underneath was scorched and exposed.
The thermal anomaly had identified genuine physical deterioration that remained hidden during normal plant operation. If left uncorrected, the damaged insulation could have led to insulation breakdown, short circuit, equipment damage, and an unplanned production outage.
The Outcome
Early detection and decisive action converted an emerging electrical fault into a controlled maintenance intervention.
The repair was completed safely in 8 hours, with:
- Zero unplanned downtime
- Zero personnel injuries
- Potential equipment and production losses avoided
Instead of discovering the defect through a trip, breakdown, smoke, or fire, the facility identified the problem while the plant was still operating and chose when and how to intervene.
Why We Do What We Do
At Technical & Engineering Solutions (TES), we believe condition monitoring is most valuable when it gives maintenance teams enough information to act before developing defects become disruptive failures.
By combining advanced condition monitoring tools, technical expertise, and actionable reporting, abnormalities that cannot be seen during routine operation can be identified, assessed, and addressed through planned maintenance.
You should not have to wait for smoke, fire, abnormal trips, or equipment shutdown to begin investigating the health of your electrical infrastructure and rotating machinery.
Protect Your Assets Before Abnormal Heat Becomes Equipment Failure
TES infrared thermography services provide non-contact inspection while equipment is operating, helping maintenance teams identify abnormal thermal conditions and make informed decisions before faults escalate.
Schedule an on-site thermal survey with TES.