Facilities Thermography Program
Buddy Williams Smith & Nephew, Orthopedics
ABSTRACT
Thermography is an important facilities maintenance tool that helps reduce unplanned downtime. Since the incorporation of thermal scans into our preventive maintenance program, we have saved tens of thousands of dollars in lost downtime alone, as well as help to keep our insurance costs at a minimum.
Thermal scans have proved themselves to be a very successful tool in locating loose connections, overloaded circuits, and other hot spots in the electrical distribution areas of our facilities. When we find a problem, we can schedule the repair for when production or other business concerns can be accommodated.
We currently scan nine buildings on an annual basis. Usually it takes a full week to scan each building. These inspections include distribution panels, switch gears, transformers, disconnects, motor control centers, tap boxes, and bus duct systems.
INTRODUCTION
Facilities equipment IR surveys are an efficient means of identifying problems under energized operating conditions. Using IR is also an excellent way to justify this preventive maintenance method.
OUR PROGRAM
About 10 years ago, our company’s insurance provider suggested that we use thermal scans on our facilities in an effort to avoid higher insurance premiums. At first, we hired a themographer to come in and scan the various parts of our electrical distribution areas. The cost for these services ranged from $10,000 to $12,000 per year. We realized that by purchasing our own camera, and receiving the proper training, we could do these scans more frequently and less expensively.
Our program is set up to scan each of our buildings on an annual basis. We currently have a Mainsaver work order tracking system that generates a work order for each of the nine buildings that we currently scan as they are due. The scans include the main switch gear/gears supplying power to the building as well as bus ducts, tap boxes, panels, dry-type transformers, motor control centers, and disconnects. All our electrical equipment has identification labels referencing their location, type of device, and component number.
When a preventive maintenance work order is generated, the thermographer has 30 days to complete the scan. Since our thermographer is also one of the facility electricians and has other responsibilities to contend with, the 30 day lead time allows him to coordinate other work orders around this schedule. The scans usually take a week to complete.
Our program is not yet set up with a “severity criteria”. The electrician makes the call, whether good or bad, based solely on his experience and situational awareness. When a device is scanned, it is written up into the report as being either good or bad. When is classified as being bad, an IR and digital image is recorded and put into the report. If it is unable to be repaired by the electrician at the time of scan, it is written up as a demand work order and scheduled for repair.
After the repairs have been made, a second scan is done to show the correction. Images are then taken and recorded in the report for future reference. We are then able to track any problems and identify any trends occurring with these devices.
Along with thermal imaging, ultrasonic testing, and multi-meters are used to identify real problems. When a thermal scan identifies a hot spot in or on a device, a multi-meter is used to identify an overloaded condition or an ultra-sonic tester to identify arching within the device. Figure 1 shows images of the control cabinet to a Roto-Clone device used for one of our polishing operations. As shown, the B-phase fuse connection is hotter than the other two fuse connections. This was caused by a loose connection on the load side of this fuse.
After applying fuse clamps to the problem area, the temperature cooled and was more even across all three phases, as shown in Figure 2. There are 24 polishing stations that are directly affected by this device. Had this problem not been found, and the device failed or had been destroyed, the replacement of this control cabinet could have taken as long as 24 hours. At an average shop rate, in this area, of $45/hour, it would have cost $25,920 in lost production time alone.
Figure 3 shows images of a dry-type transformer used to supply power to a bus duct system which, in turn, supplies power to 60 manufacturing machines/devices. The images shown are a hot B-phase lug connection. After removing power from the device and examining the problem, it was discovered the lug was loose.
Figure 4 shows the corrected temperature after the lug was tightened. Had this transformer failed, it could have taken a minimum of eight hours to replace it. At an average shop rate of $86/hour, it would have cost $41,280 in lost production time alone.
SURVEYS
Figure 1 is the IR/digital image of the B-phase fuse connection in a control cabinet disconnect. As shown, the fuse has loosened at the load side connection.
Figure 1. Thermogram/photo pair showing problem on the load side of B-phase in control cabinet disconnect.
Figure 2 is the IR/digital image after the correction has been made to the Roto-Clone control disconnect.
Figure 2. Thermogram/photo pair showing a correction in temperature of the load side of the B-phase in control cabinet disconnect.
Figure 3 is an IR/digital image of a 225 KVA dry-type transformer showing a hot B-phase tap connection.
Figure 3. Thermogram/photo pair showing a problem with 225 KVA transformer supplying power to shop floor bus duct.
Figure 4 is the IR/digital image of the 225 KVA dry-type transformer after the B-phase lug was tightened.
Figure 4. Thermogram/photo pair showing the corrected temperature of the 225 KVA transformer.
SUMMARY
Finding problems with electrical panels and distribution devices before real damage occurs is the key to any preventive maintenance program. With infrared, these and other issues can be scheduled for repair when production and other business related concerns can be accommodated. By identifying and recording these problems, management can reference your material and see first hand, how the preventive maintenance program is saving the company thousands of dollars.
ACKNOWLEDGEMENTS
The author wishes to thank the Infrared Training Center at FLIR Systems and Smith & Nephew for providing the resources to make this work possible.
ABOUT THE AUTHOR
Buddy Williams is a Level III thermographer and has been using infrared technology for 3 years. He is also a master electrician with over 17 years of experience.