As part of my duties as an instructor and consultant for The Snell Group, I have traveled to many different cities and countries. During my travels I have had the privilege of training and working with numerous thermography and condition monitoring (CM) professionals. One commonality that I’ve noticed is that the use of thermography is expanding and is becoming an even more highly valued and useful tool for CM professionals as part of their maintenance programs. An important aspect of using IR thermography as part of your maintenance program is knowing when to inspect electrical and mechanical equipment with IR. “When to inspect?” is the topic of this month’s tip.

One of the more obvious answers to this question is: Use IR when trying to locate and troubleshoot thermal anomalies or suspected problems. This leads directly into the next occasion to inspect equipment with IR; always re-inspect equipment after repairs have been completed to ensure that the repairs were performed correctly and that the problem has been fixed. It’s also good practice to inspect any piece of mechanical or electrical equipment that has been modified or changed after the modifications have been made. Seasonal changes are another great time to inspect equipment with IR. For example, after a drastic change in temperatures has occurred as happens from winter to summer, especially in northern climates, you should conduct an IR inspection of equipment. (Keep in mind, drastic changes in temperature can also occur in southern climates as well.)

Any time you receive new equipment you should do a commissioning inspection for validation purposes. Keep in mind that to do this type of inspection the equipment must be under load. NFPA 70B suggests a minimum of 40% load for inspecting electrical equipment. With no load, we won’t be able to detect any significant changes on the thermal signatures of the equipment being inspected. Images taken of new equipment that is operating normally provides the opportunity to establish a baseline for that piece of equipment. This baseline can be used as a reference to compare images from subsequent thermal inspections, as long as the equipment is operating under similar conditions as when the baseline image was taken.

The occasions to inspect mentioned above are what we refer to as “off route” inspections.  This is because the inspection of equipment on these occasions is done regardless of the timing prescribed by your established routes and inspection frequencies. To have a well functioning IR program, it is very important to first establish routes and frequencies, and then periodically review them. Established routes and frequencies provide CM professionals a schedule to routinely inspect their equipment. When creating periodical inspection routes, consult with everyone involved: the maintenance department, production personnel, the safety department, and management or supervisors. Consulting with the necessary departments will provide you with valuable information about each piece of equipment, such as the criticality of each item and the possible consequences of failure. This will also help you determine when you should schedule periodic inspections due to factors such as failure modes, peak loads and peak production periods.

There are many different approaches that can be taken to determine when to conduct IR inspections of equipment. It is important to discuss this with all the key players at a plant or facility to figure out the approach that works best for your particular set of equipment and to get the most out of your maintenance or CM program. A well planned and implemented IR program will help to reduce maintenance costs and reduce expensive downtime. Always remember the 7 P’s: Proper Planning, Preparation and Practice Prevents Poor Performance!