Thermal Imaging Camera Finds Robotic Weld Gun Problems

n March of 2001 a GM production foreman asked J & R Thermography to find the source of a foul burning rubber odor. Upon scanning the area with a thermal imaging camera, the team discovered a 500 MCM air cooled ribbon (ribbon 1) that was dangerously overheated. Figure 1 shows the original thermal imaging scan of the area showing a temperature of 208 degrees C on ribbon 1. The rubber sheath on these cables was pretty loose, so true temperature readings of the actual cable were impossible while using our thermal imaging camera. When operating normally, the thermal imaging camera found that this ribbon has a temperature of 30-50 degrees C. Ribbon 1 was replaced at the next down time. Further investigation with my thermal imaging camera shows somewhat higher temps on the other ribbon (ribbon 2) as well. An inspection with a thermal imaging camera after the first ribbons' replacement (Figure 3) showed normal operating temperatures on ribbon 1. Ribbon 2 also showed a decrease of 30 degrees C after repair but is still slightly higher than normal. The decrease in temperature may be due to less conduction from ribbon 1, and also less compensation for the breakdown of ribbon 1. Low emmisivity made reflection a non-issue. It was advised that ribbon 2 be inspected every day with our thermal imaging camera and replaced when temperatures consistently reached 95 degrees C. Further inspections with our thermal imaging camera may reveal the need to replace the air cooled ribbons with water cooled ones.