Thermographic surveys for electrical maintenance
Infrared thermography finds loose joints and overloaded circuits before they fail. What a thermal survey covers, how to read the images, and how often to schedule one.
Al Sanaya Commissioning
·7 min read
Almost every electrical fault announces itself as heat before it fails. A bolt that has worked loose, a corroded lug, an overloaded feeder — each runs hotter than its neighbours for weeks or months first. An infrared thermographic survey reads that heat through the camera and turns an unplanned outage into a scheduled repair.
What the survey looks for
A thermographer scans live switchgear, distribution boards, busduct joints, cable terminations and motor circuits, comparing the temperature of each component with its phases and its neighbours. The defects that show up are consistent:
- Loose or under-torqued connections
- Corroded or oxidised joints and lugs
- Overloaded circuits and undersized conductors
- Phase imbalance across a three-phase load
- Deteriorating contacts in breakers and contactors
Reading the images
A thermal image is not read by absolute temperature alone — ambient conditions and load change that figure constantly. It is read by comparison. A connection markedly hotter than the identical connection on the other two phases, under the same load, is a defect regardless of the raw number.
Findings are usually graded by temperature rise above reference: a small rise is monitored, a moderate rise is scheduled for repair, and a severe rise is acted on urgently.
Surveys must be done under load
Heat only appears when current flows. A survey carried out on lightly loaded or de-energised equipment will miss the very faults it is meant to find. Surveys are therefore planned around normal operation, ideally with equipment at 40% of rated load or more, so a developing hotspot has reason to show itself.
Why it matters in the GCC
High ambient temperature is the GCC's hidden stress on electrical equipment. A connection with slightly elevated resistance may sit unnoticed through winter and then overheat once summer ambient climbs. Running a thermographic survey before the summer peak catches those marginal joints while there is still time to act, and pairs naturally with a planned switchgear maintenance programme.
From survey to action
The value of thermography is direction. Instead of re-torquing every connection on a maintenance shutdown, the survey report names the specific joints, feeders and devices that need attention — and the next survey confirms the repair worked. Over time the reports also build a trend record of how the installation is ageing.
How Al Sanaya can help
Our commissioning team carries out infrared thermographic surveys on switchgear, busduct and distribution systems across the GCC and MENA, delivers a graded findings report, and helps schedule surveys around the summer peak as part of a predictive maintenance programme.
Frequently asked questions
What does a thermographic survey detect?
An infrared survey detects abnormal heat — the signature of loose or corroded connections, overloaded circuits, phase imbalance, failing contacts and undersized conductors. Most electrical faults give off heat long before they fail, so thermography catches them early.
Does equipment need to be running during the survey?
Yes. Thermography is most useful under load — ideally at 40% of rated load or more. A circuit that is switched off or lightly loaded will not reveal a developing hotspot, so surveys are planned around normal operating conditions.
How often should an electrical thermal survey be done?
Annually for most installations, and more often for critical or heavily loaded equipment. In the GCC, scheduling a survey ahead of the summer peak is good practice, because high ambient temperatures push marginal connections over the edge.
Is thermography a substitute for maintenance?
No — it directs maintenance. Thermography tells you which connections to re-torque, which loads to investigate and which equipment to prioritise, so planned maintenance effort goes where it is actually needed instead of being spread evenly.
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