The cost of Infrared cameras has come down dramatically in the past 10 years. Smartphones with a built-in IR camera with both still and video recording capability are now available for less than $700 while a very good mid-range handheld camera now costs less than $4,000. Low-end cameras may not have all the settings needed to get accurate temperature readings but will allow for good qualitative analysis. A mid-range camera will allow both qualitative and quantitative measurements to be made. It is recommended that personnel attend an accredited level 1 thermography training course before attempting to use an IR camera as the danger of both missing real problems and reporting false positives is possible without proper training.
Infrared is not x-ray vision-infrared energy will not transmit through solid substances like sheet metal. You can attempt to compare sequential busway joints from their exterior to look for temperature variation but the busway itself has significant thermal mass. A problem that is causing a 50°C temperature rise on a loose connection inside the joint might manifest as only 1-2°C of temperature variance on the exterior of the joint, which can easily be missed. The joint cover, when opened for inspection, allows a direct field of view of the internal connections of the joint ensuring that any problem will be seen immediately.
At a minimum, we recommend annual scanning of busway joints. In critical power applications such as data centers, hospitals, airports and some industrial applications, more frequent inspection may be prudent. In these segments, it is not unusual for inspections to be done on a quarterly basis. Eaton Busway falls under NEMA BU1.1 for all busway maintenance.
Temperature abnormalities constitutes any yearly temperature scans of the same joint showing margins of rise greater than 5°C. During a joint scan, note the ambient temperature of the room for each scan and if any changes were made to the electrical system, as a new load may affect operating temperatures of the busway. Different phases at one joint may also run at higher or lower temperatures than other phase at the same joint, depending on the load incurred by the individual circuit.
Double check your camera settings and record the time, location and temperature values of the suspect busway connection. Note which phase was manifesting as the source of the heat, if applicable. Changes above 5°C of the same joint, during a yearly scan per NEMA BU1.1, would have a recommended action of a visual inspection to check for any changes in the busway during the year and possibly de-energize the busway to check torque values of the busways bridge joints.