The overheating of switchgear equipment continues to be a major factor responsible for failure of LT installations. Almost all switchgear standards specify the permissible temperature rise limits while continuously carrying the current as a prime requirement mainly from the point of view of reliable operation of switchgear. However, quite a number of switchgear installations suffer from overheating and burning while carrying less than the rated current. The timely detection and necessary corrective action if not attended at proper time may lead to more disastrous failures like flashover with a high potential to cause enormous damage both in downtime and hazard. This overheating is normally with no telltale signs that can be visually or otherwise sensed. Infrared thermography is finding useful application towards the objective for condition monitoring and integrity assurance of LT switchgear reliably and effectively.

This paper highlights condition monitoring by Infrared Imaging of LT switchgear PCC Incomers being carried out at BPCL Refinery, illustrating the cases with colour thermographs.