Most electrical failures in commercial switchboards give a warning before they happen. The warning is heat. A loose termination, an overloaded cable or a failing breaker runs hotter than it should for weeks or months before it trips, melts or starts a fire. Thermal imaging lets us see that heat while the board is running, without shutting anything down.
How thermal imaging works
A thermal imaging camera detects infrared radiation and shows it as a temperature image. On a switchboard, normal components show up at a fairly even temperature under load. A problem shows up as a hot spot: one phase warmer than the other two, one terminal glowing brighter than its neighbours, or a cable running hotter than the rest of the bundle.
Because the scan is done with the board energised and under normal load, it shows how the equipment actually behaves in service. That’s something a visual inspection or a test with the power off can’t tell you.
What a thermal scan picks up
The faults we most often find include:
- Loose or poorly made terminations on breakers, busbars and neutral links
- Unbalanced loads, where one phase is carrying much more current than the others
- Overloaded circuits and cables running close to or beyond their rating
- Breakers, contactors and isolators with internal wear or failing contacts
- Corrosion on connections, which is common in coastal buildings and plant rooms
- Fuses and fuse holders with poor contact
Loose connections are the big one. Terminals can loosen over time through thermal cycling, vibration from nearby plant, or simply because they weren’t tightened correctly in the first place. A loose connection has higher resistance, which creates heat, which makes the connection worse. Left alone, it can end in a failed component or a fire.
Where thermal imaging makes the most sense
Thermal scanning is useful anywhere a failure would be expensive or disruptive. That includes:
- Main switchboards and distribution boards in commercial and strata buildings
- Industrial sites with motor control centres, compressors and production equipment
- Shopping centres, hospitality venues and medical practices where downtime affects trading or care
- Data rooms and comms cabinets with UPS systems
- Older buildings where the switchboard has been extended many times
It’s also a useful check after major works. If a board has had new circuits added during a fit-out, a scan once the tenant is trading confirms the new load is sitting comfortably.
How a survey is carried out
We schedule scans for when the site is running normally, because a board with little load won’t show much. Covers are removed by a licensed electrician with appropriate safety controls in place, as this is work near exposed live parts. We work under a SWMS for the task and set up barriers so staff and the public are kept clear.
Each board is scanned and any hot spots are photographed with both a thermal and a standard image, so the location is easy to identify later. We note the load at the time of the scan, because temperature readings only make sense relative to how hard the circuit is working.
What the report tells you
A useful thermal imaging report doesn’t just list temperatures. It ranks findings by priority, explains what the likely cause is, and recommends what to do about it. Some faults need attention straight away. Others can be scheduled for the next planned shutdown.
We provide a written report with images for each finding, the location, the likely cause and a recommended fix. Many repairs, such as retightening a termination or replacing a single breaker, are small jobs once the problem is known. Where a board is showing widespread issues, it may be time to consider a switchboard upgrade instead of repeated repairs.
How often to scan
There’s no single rule for how often a switchboard should be scanned. Many businesses scan once a year as part of preventative maintenance, and some insurers ask for regular thermal surveys as a condition of cover for certain types of premises. Sites with heavy loads, critical equipment or a history of faults may scan more often.
The best approach is to scan regularly enough that problems are caught early, and to keep the reports so you can compare results over time. A connection that is slightly warmer this year than last year is worth watching. Thermal imaging fits naturally into a preventative maintenance plan alongside RCD testing and emergency lighting checks.
Limits of thermal imaging
Thermal imaging is a strong tool, but it isn’t everything. It can only see surfaces it has a line of sight to, so connections hidden behind shrouds or inside enclosed equipment may not show up. Lightly loaded circuits may not show a fault that would appear under full load. And it tells you where there’s heat, not always why, so an electrician still needs to investigate each finding.
Thermal imaging also doesn’t replace other testing. RCDs still need their own tests, insulation faults may not show heat at all, and emergency lighting has its own inspection regime. It’s one tool in a maintenance program, not the whole program.
That’s why we treat a scan as the start of the conversation rather than the end. The images guide where to look, and the repair is done properly once the cause is confirmed.
Booking a thermal survey
Our thermal imaging service covers commercial, strata and industrial sites across the Gold Coast, Brisbane and Northern NSW. We can scan once, or include it in a regular maintenance program. Send us a list of your boards and we’ll give you a written quote and suggest a time when the site is running normally.
Safety note: electrical work in Queensland and NSW must be done by a licensed electrician. This article is general information, not advice for your specific property. If something looks or smells wrong, switch off at the main switch if it’s safe to do so and call an electrician.