We have thermography survey PM for electrical equipment such as switchboard, distribution boards, MCC etc. At what frequency should we do this? Any standards as guidance?

When performing electrical IR scanning, a frequency of quarterly is the accepted standard. I would also strongly suggest complimenting this activity with Airborne Ultrasonics as well both from a safety standpoint as well as early detection of additional failures that IR may not pick up on.

Is there any Electrical standard for thermography?

We are using thermography for last 6months on more than 900 equipments. This include MCC, Distribution boards, breakers, hydraulic, furnace tubes and so on.. The frequency of survey is mainly based on the criticality which the plant personnel will provide. Then we adjust the frequency of survey based on the frequency of faults we detected.

One thing to remember, there are numerous failure modes you are attempting to detect with your IR scanning and each of those failures have a different P-F curve. Therefore, you have to be sure you are allowing yourself 1.) the ability to detect each of those failures within the P-F as well as 2.) giving yourself the benefit of the doubt to catch any random failures that may occur.

Tim, do you have any write up or standard?

Tim - please elaborate a little more why you strongly recommend ultrasound during infrared inspections.

First for Josh.
No I do not have any write up. What I do have is 8 years experience in my line of work setting up Reliability Based Maintnenace programs for our customers. Industry standards that I quote come from information given by the people I know who are the expert practitioners with their respective PdM technologies. I will follow up with an IR buddy of mine to find out what he has and get back with you.
Now, for Pete. Airborne Ultrasonics has an incredible ability to detect arcing, corona, and tracking. I am sure you understand that these failures create friction in the air and thereby are detectable with IR. However, in the early onset of the failure, there may not be enough friction to generate that heat. The air molecules though, are being disturbed and therefore are audible with Ultrasonics. So why am I an advocate? First would be safety. I am not an electrical genius by any sense of the word but I do know that electricity 'bites' and it doesn't feel good. A simple scan around the door of a cabinet before opening it to look with an IR Camera can prevent a potentially dangerous situation. Secondly, from a reliability standpoint, our goal as practitioners is to detect potential failures as far up the P-F curve as possible. This drives proper planning and scheduling which in turn drives financial results to the bottom line.

Astm E1934

Craig