What should a thermography survey of a data centre LV main switchboard include?

Every energised connection that can be viewed safely: incoming cable or busbar terminations, incomer and bus section connections, outgoing device terminations, neutral bars, and visible control and metering terminals. The survey is done live and under load, the load is recorded, and anything that could not be viewed, such as connections inside a withdrawable breaker cradle, is listed in the report.

Why the main switchboard matters

In a data centre the LV main switchboard sits between the transformer and everything downstream: UPS, mechanical plant, and the busbar and PDUs that feed the data halls. It usually carries the highest currents on site. A survey that covers the data hall but skips the switch room misses the start of the power path. See surveying the whole power path.

What the survey should cover

Incoming supply. Transformer cable or busbar terminations at the incomer.
Incomers and bus sections. The external connections on incoming and bus section breakers, and busbar joints that can be viewed.
Outgoing ways. Cable terminations on each outgoing breaker, including feeds to UPS, mechanical services and generators.
Neutral bars. Neutral terminations carry current too. See neutral connections in a data centre survey.
Control and metering. Visible control wiring, metering and auxiliary supply terminals.

What it can’t see

Thermography measures the surface it can see. On withdrawable breakers, the main contacts inside the cradle are usually hidden behind the breaker and its shutters. Busbar joints behind solid barriers are hidden too. The survey images what can be safely viewed with covers opened by the site’s authorised electrician, and the report lists anything that could not be viewed rather than marking it clear. Where a panel is surveyed often and can’t be opened easily, infrared windows can help. See infrared windows and what thermography can’t detect.

Live, with no shutdown

The switchboard stays in service. Covers are opened under the site’s permit to work, and the thermographer images each connection from a safe distance. See surveying UPS and switchgear without a shutdown.

Load and reporting

A reading means little without the load behind it, so the current on each incomer and the main outgoing ways is recorded with the image. In a 2N design each side may carry only part of its rating, which is worth knowing before the survey date is set. See what load a survey needs. Each finding is reported with where the reading was taken, the measured temperature, the reference, the difference in °C and the load at the time.

Proof from our own work

On a London data centre build, commissioning thermography by our team found 16 busbar sections reading above 80 °C under test load, the highest 103.5 °C at a tap-off unit, each one located and imaged. The same approach, every connection viewed under load and recorded, applies in the switch room.

Ti inspects and reports. Any finding is investigated and put right by the site’s electrical team or contractor.

Frequently asked questions

Can the main switchboard be surveyed without a shutdown?

Yes. It is surveyed live, with covers opened by the site’s authorised electrician under permit to work.

Are the breaker main contacts checked?

Only where they can be seen. Contacts inside a withdrawable cradle are usually hidden, and the report says so.

How often should it be surveyed?

At commissioning, then at least once a year. See annual PPM thermography.