Should chiller, CRAH and pump panels be included in a data centre electrical thermography survey?

Yes. Cooling keeps the IT load running just as much as the UPS does, and the electrical side of the cooling plant can be imaged live in the same visit: the panels, motor control centres, drives and isolators that feed chillers, CRAH or CRAC units and pumps. Survey while the plant is running at a typical duty, so those connections are carrying current.

Why the cooling plant electrics get left off

Most data centre thermography scopes are drawn along the IT power path: HV and LV switchboards, UPS, busbar, tap-offs and PDUs. The mechanical plant is often maintained under a separate M&E contract, and its panels sit in plant rooms, on the roof or in an external compound rather than in the data halls. So the boards that feed the cooling can drop out of the electrical survey without anyone deciding they should.

They carry load around the clock, many are outdoors, and a trip on a chiller or CRAH supply is a cooling problem within minutes. They belong on the same asset list as the rest of the critical power.

What can be imaged

Mechanical services panels and the sub-mains that supply them
Motor control centres, starters and contactors for pumps and fans
Variable speed drive panels: incoming and outgoing terminations, and the drive itself where the cover can be safely opened
Local isolators at CRAH and CRAC units, pumps and dry coolers
The incoming supply terminations of chillers, where the manufacturer allows the panel to be opened

Covers are opened by the site’s authorised person or the plant maintenance contractor. Inside a chiller’s own control panel, the manufacturer’s rules decide who may open it. Anything that can’t be safely seen is listed in the report as not inspected, with the reason.

When to survey

A connection only shows its condition when current flows through it. Cooling load moves with the IT load and the weather, and most plant runs on a duty and standby rota. Agree with the site which units are on duty on the day, and where the change process allows, ask for standby units to be rotated in so they are imaged working too. We record the conditions and, where the panel or drive displays it, the current with each image, so next year’s survey compares like for like.

What to watch for on plant panels

Some heat is there by design. Drive heat sinks run warm, outdoor panels often have anti-condensation heaters, and a rooftop enclosure can be heated by the sun. A good survey reads those for what they are. Findings are judged against like for like: the same phase on the other two phases, the same drive on the neighbouring pump, the duty unit against its standby. Each finding is reported as a measured temperature, where it was taken, and the difference in °C from its reference.

Proof from our data centre work

We cover the cooling plant in the same report as the IT power path, so the operator gets one record. On one London data centre build this autumn, our commissioning thermography recorded 16 busbar sections reading above 80 °C under test load, the highest 103.5 °C at a tap-off unit. Plant supplies get the same treatment: imaged under real operating load, every reading located and compared. Ti inspects and reports; the client’s electrical team or contractor investigates and carries out any work.

Frequently asked questions

Can the cooling plant be surveyed in the same visit as the switchgear and UPS?

Yes. Plant room and rooftop panels are usually added to the same visit, so the report follows the power path from the switchboard to both the IT load and the cooling.

Does the plant need to be at full load?

No, but it needs to be running. The report records the load at the time and says plainly where a reading was taken at low load.

Who opens the panels?

The site’s authorised person or the M&E contractor. Our thermographers image what is opened and do not operate any switchgear or plant.