Thermal Imaging

The temperatures of electrical components and connections are indicative of their health. Excessive heat due to increased electrical resistance will be generated by faulty components and by loose, oxidised or corroded connections. Equipment running hot can also be related to poor assembly, overloading, failure of cooling etc. Conventional techniques such as impedance testing and torque checking have a relatively low effectiveness in detecting and preventing failure due to these causes. Thermal imaging is a non-contact on-line technique which can be employed to detect these temperature rises as "hot spots". Identification of hot spots can be used to trigger remedial work, reducing the number of defects and improving reliability. The two key benefits available from the reduction in defects are:

• Increased plant availability - this can be greatly beneficial : cost ratio for key installations supporting business-critical functions, eg computer centres. It should also be noted that thermal imaging can be (and is best) done with the plant on-line, reducing the need to take critical plant off-line for testing which in itself would reduce availability.
• Avoidance of consequential damage - this can be damage to the installation itself, connected plant, or other damage due to fire or explosion for example.

Feedback from thermal imaging of electrical installations shows a significant rate of potential fault detection for an initial survey, typically in the region of one to two faults for every 10 panels inspected.