Thermography is a Predictive Approach to maintenance because a failure can be costly for end users in terms of lost production and revenues and lead to lower revenues for the Plant from lost sales due to unreliable service. Since overheating as well as abnormally cool operating temperatures may signal the degradation of an electrical component, thermal imagers provide the predictive capabilities required for panel and switchgear maintenance.
All electrical systems, equipment and components are subject to deterioration once commissioned. This deterioration may be in many forms:
For example, loose or corroded connections and joints, insulation resistance breakdown or worn and pitted parts.
These poor electrical connections result in a high resistance across the connection with a subsequent rise in temperature. If this un-checked and not corrected rise in temperature will continue to increase, overheating will occur, leading to system, equipment and component failure.
In the most extreme circumstances system or equipment failure can result in fire and possible explosion.
Additionally, excessive loading of electrical systems and equipment or phase imbalance of electrical systems may also lead to failure.
The deterioration and loading of electrical systems and equipment is not always apparent or detected by conventional checks such as routine monitoring and maintenance or periodic test and inspection.
However, when energized and under load, these faults can become clearly visible with the aid of thermal imaging techniques.
In many cases this allows for instant fault diagnosis which in serious cases can be brought to the customer’s attention immediately, allowing the necessary remedial action to take place at an early stage.