The factory that I work at hires a company to come in and do IR scanning of all local disconnects and MCC buckets once a year. The technician spends an 8 hour day here.
They send us back a notebook documenting all of the problems. Each page of the notebook documents a single problem, and lists location, the temperature rise, probable cause, and recommended course for repair. Also, each page has a standard colored photo with arrows pointing to problem area, and a black and white infrared thermagram.
I personally have assisted the technician several times. Until a few years back, they used some real cumbersome video equipment that required liquid nitrogen cooling. The later equipment is much smaller, and does not require the liquid nitrogen. I do know that the equipment is very expensive.
When a problem is found, the technician videos the piece of equipment, and tunes the camera to determine the actual temperature rise. During the video, he speaks into a microphone and describes everything so that he can later compile the notebook of problems. He then snaps a standard 35mm photo. Some of the common problems that we find are worn out disconnect contacts, bad fuse clips, loose or corroded terminations, and blown fuses on power factor correction capacitors.
This service costs around $2000.00 a year, but we have found that it more than pays for itself in preventing down time.
