If the busbar joints have been torque-checked, does a data centre still need thermography at commissioning?

Yes. A torque check and thermography answer different questions. The torque record shows each busbar joint was tightened to the set value at installation. Thermography under load shows how each joint behaves when current flows through it. On a data centre build, both belong in the handover evidence, and neither replaces the other.

What a torque check tells you

Installers tighten busbar joint bolts to the manufacturer’s torque value and usually mark them, so anyone can see the joint has been done. That record matters. It shows the installation was carried out to the method, joint by joint, before the system was energised.

What it can’t show is the joint carrying current. It is a check of the fixing, made with the system dead.

What thermography under load adds

Thermography is a non-contact check of the joint while it is working. Imaged during a load bank test, a busbar run shows whether any section, joint or tap-off is warmer than the sections around it under the same load. The report gives the measured temperature, where it was taken and the reference it was compared with. It doesn’t diagnose the cause of a warm joint. That is for the installer to investigate, and the joint can be re-imaged afterwards.

Why both belong in the handover pack

The torque record is evidence of how the system was built. The thermal record is evidence of how it performed under test load before the client took it over. Together they give operations a starting point: the next survey, on a live hall, is compared against a known baseline rather than against nothing.

What commissioning thermography found on one London build

On a 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. Each one was located against the drawings, so it could be found, checked by the installer and re-imaged before handover. Client and site are not named.

When to book the thermography

During the load bank or integrated systems test, when the busbar carries current, and before the halls go live. Agree the test steps with the commissioning manager, and make sure the installer’s authorised person is there to open tap-off units. Ti inspects and reports; the installer carries out any work.

Frequently asked questions

If the joints were torqued and marked, is a thermal survey a duplicate?

No. One checks the fixing with the system dead, the other checks the joint carrying current. They answer different questions.

Can a re-torque replace re-imaging a warm joint?

Whatever the installer does to a joint, re-imaging it under load is the way to show the result on the record.

Does the same apply after handover?

Yes. A periodic survey of the live hall is compared with the commissioning baseline, so any change in a joint shows up.