What should an electrical thermography survey cover at a paper mill or corrugated packaging plant?

Short answer: cover the intake and main switchboards, the MCCs and sectional drive line-ups for the paper machine or corrugator, the steam and boiler plant panels, vacuum and compressor panels, and converting and baling lines. Survey at production speed on a steady grade or order, not during a grade change, web break or set-up.

Why paper and board lines need a planned survey

A paper machine or corrugator is one long line held together by its drives. Dozens of sectional drives, pumps and fans run off a few motor control centres and drive line-ups, and an unplanned stop means lost speed, wasted reel or board and a slow restart. Most mills and box plants run shifts around the clock.

Thermography checks the connections feeding that equipment under real load, with no shutdown, so anything that stands out can be planned into the next scheduled stop.

What to include

Intake, main LV switchboards and sub-boards for each machine hall, converting and warehouse
Sectional drive line-ups: drive cabinets, inverters, contactors and terminals for each section
MCCs for stock preparation pumps, agitators and fans
Steam and boiler plant panels, plus vacuum pump and compressor panels
Corrugator and converting: splicers, glue kitchen, slitter-scorers, printer-slotters, folder-gluers and their panels
Baling and waste handling panels

Any equipment the manufacturer says must stay closed, or that runs at high voltage inside the unit, is left closed and listed on the report as not imaged.

Timing: steady production, not changes

During a grade change, a web break or order set-up, drives slow, stop or swing in load. We agree the route with the shift manager so each line-up is imaged while the machine is running at production speed on a steady grade or order. The load is recorded with every image, so next year’s survey compares like with like.

Heat traps a thermographer has to rule out

Process heat: steam-heated dryer cylinders, hoods, preheaters and steam pipework are hot by design. Readings are taken at the electrical connection, not the plant.
Humidity and steam: moist air near the wet end and dryer section affects what the camera sees at distance, so panels are imaged close and with the cover open where it is safe to do so.
Reflections: polished rolls and bare metal reflect heat from nearby equipment, so the angle is changed and the reading checked.
Cabinet cooling: drive cabinets often have their own fans or coolers, so doors are opened by your authorised electrician and connections imaged directly.

What the report gives you

Each finding comes with its location by line-up, cabinet and circuit, a thermal image with a matching photo, the measured temperature, the load at the time and the difference in °C from a matching phase or identical unit. Ti inspects and reports; your maintenance team or the machine supplier carries out any work. Reports are on our online portal, usually the same or next working day.

Frequently asked questions

Does the machine need to stop?

No. Thermography needs the equipment running. Covers are opened one at a time by your authorised electrician while production carries on.

How often should a mill or box plant be surveyed?

Once a year is a common minimum. Sites running around the clock, or with older drive line-ups, often survey every six months.

Should the survey be done just before a planned shutdown?

Often, yes. Surveying a few weeks before the stop gives your maintenance team time to plan any work into it.