What should a site send and prepare before an electrical thermography survey?

Five things make an electrical thermography survey run smoothly: a list of the boards and panels in scope, keys and access to every switch room and plant room, an authorised electrician to open covers, a date when the building runs at its normal load, and last year’s report if there is one. With those in place, nothing needs switching off and the report follows your own references.

1. A list of what is in scope

Send a board schedule, asset register or single line diagram before the day: main switchboard, sub-mains, distribution boards, motor control centres, plant panels and anything else to be imaged. Use the names on the boards themselves, so every finding in the report matches the label your electrician will see. If the list is out of date, say so. Anything found on the day that isn’t on it is recorded as found, and the list can be corrected for next year.

2. Access, keys and a route

Keys or fobs for switch rooms, risers, plant rooms and roof plant
Any areas that need an escort, a permit or a set time, such as kitchens, clean areas or tenant spaces
Site induction, parking and sign-in arrangements
A named contact on the day who can answer “what does this board feed?”

A route agreed in advance saves more time on the day than anything else (see what affects the cost and duration).

3. Someone to open the panels

Thermography needs a line of sight to the connections, so covers have to come off. That is done by the site’s authorised electrician or maintenance contractor, under the site’s own safe system of work, and the covers go back on afterwards. Our thermographers image and record; they don’t remove covers or touch the equipment (see who opens the panels). Anything that can’t be opened safely is recorded as not inspected, with the reason.

4. A day with normal load

A poor connection shows by the heat it gives off while current flows through it. Book a normal working day, at a normal busy time, not a quiet week, a bank holiday or a planned shutdown (see what load a survey needs and the best time of year). If some plant only runs at certain times, such as pumps, chillers or floodlights, tell us so the visit can catch it running.

5. Last year’s report

If the site has been surveyed before, send the previous report. Findings can be re-checked, the same board order kept, and change from one year to the next shown in °C rather than guessed.

What you get afterwards

A report that locates every finding by board, circuit and phase, with the measured temperature, where it was taken, the difference in °C from a matching reference and the load at the time. Ti Thermal Imaging issues it the same day. Ti inspects and reports; your electrical contractor investigates findings with the circuit isolated and carries out the work.

Why preparation shows in the results

On a London data centre build, commissioning thermography by our team recorded 16 busbar sections reading above 80 °C under test load, the highest 103.5 °C at a tap-off unit. Because each section was located against the drawings, every one could be found, checked by the installer and re-imaged. A good board list does the same job in an office, school or factory.

Frequently asked questions

Does anything need to be switched off?

No. The survey looks at equipment as it runs. Only covers are opened, by site staff.

Do occupants need to be told?

That’s the site’s call. Most give the usual notice that a contractor will be in plant rooms and risers.

We don’t have a board list. Can the survey still go ahead?

Yes. The thermographer records each board as found, and the report becomes the start of your list.