Innovation in Utility Power Line Infrared Imaging

Oregon Infrared has been performing quality thermographic services in the Pacific Northwest region since 1997. The organization has been on a constant upward climb since its beginnings, and its reputation for safety, reliability, and accuracy is well known. As sales and marketing efforts continue to create opportunities, new applications for the service arise and are capitalized upon. 

During the year 2000 a contract was let for utility power line Infrared imaging for one of the local public utility districts. Being a competitive business and knowledgeable of the electrical industry, I was very conscious of expense outlays to satisfy the needs of the job. Yet I was still striving to provide the highest quality and value product to the customers. I therefore created a tool that allows maximum speed and accuracy for report gathering at minimal expense. The following information shows how I gathered data for utility power lines and substations with this tool.

Early in 2000, I was approached by a public utility district to look at some pedestal mount 12.5 kV switchgear. We were doing basic infrared imaging for loose connections and overloads. They were impressed with my product and asked me to do some additional Infrared imaging on some power poles. There were some suspect areas that they were aware of and wanted to confirm the problem spots (of course I said, "that'll be extra"). 

We scanned several pole-mounted switches from a bucket truck and several anomalies were located and recorded. As a result of the information gathered, a new contract was offered to do a drive-by scan of all the 115kv transmission lines in the PUD district later in the year. 

This equated into about 170 miles of line and 42 substations to be done in 6 days in December. It is pretty much guaranteed to be raining at this time of year and the prospect of hanging our infrared camera out of the door of a truck for 6 days in inclement weather was not very appealing. All kinds of damage to the equipment were imaginable. It became important to devise a way to provide the service while lowering the risk to the camera. It was time to put on the thinking cap and find a solution. Some of the criteria had to be:

1) Protect IR camera from environment
2) Protect IR camera from physical damage
3) Ease of use
4) Low cost to produce

The result was an acrylic box with a camera tripod head mounted to a platform. These two pieces would be then attached together and mounted and secured to a truck door.

IR camera in acrylic box

The idea of the box is to provide a safe environment for the IR camera as it travels outside the vehicle, while allowing the data to be gathered safely and in relative comfort inside the cab. One of the criteria for construction was that the box have doors to provide access to the buttons that operate the camera functions. 

This particular box was designed to accommodate a Flir (Inframetrics) model PM 280. Vibration control was also incorporated at as many points as possible. The tool needed to be flexible enough in design to accommodate the shapes of various different vehicle doors. Ease of setup was also considered. Another important piece of criteria was the protection of the lens from the elements and protection of the IR detector from random exposure to sunlight.

These ideas were brought to a plastics fabrication shop: Spectrum Plastics, Portland Or.
503-626-8284. The owner and I spent several hours exploring ideas, functions and material selection. We discussed different approaches to solve and provide for all of the needs of this enterprise. After much brainstorming, a design was settled on, rough drafts were drawn, and production commenced.

It is understood that the window of the cab will be open while Infrared imaging with this design. As it turned out, the size and shape of the box acted as a windbreak, and the interior of the cab stayed relatively warm and rain free.

The complete system for Infrared imaging consists of the box and platform that attaches to the outside of a vehicle door and a tripod mounted 8mm camcorder located in front of the thermographers seat. The video signal from the IR camera dumps into the camcorder via a video cable. This allows for viewing images either at the eyepiece or the fold out screen on the 8mm camcorder. This also allows for videotaping the thermal images. Visual images can be taped through the front windshield.

The main benefit of this whole idea was the reduced cost of Infrared imaging utility power lines and substations as opposed to purchasing and outfitting a van dedicated to Infrared imaging. This allows an infrared service company like Oregon Infrared to provide a high quality product for a reasonable price.

The setup time for assembling the equipment, plugging in all the cords, turning everything on, and doing a system check takes about 15 minutes. Usually after everything checks out OK and there is driving time involved before the start of the route, the equipment is all turned off and the IR camera is removed from the box and stored in its case. If there are any problems, it is best to solve them at the start of the Infrared imaging day at home base rather than discovering them out in the field.

When arriving at the beginning of the route, install the IR camera in the box securing it with the bolt through the box, hook up the video out cable to the camcorder and settle in for a long day of sitting and infrared imaging. Remember the coffee. Remember your social skills.

Another idea that emerged out of necessity was overcoming the small space inside the box that was available for reaching in and focusing the lens. A simple solution was a hose clamp purchased from a hardware store. A hole was drilled into the clamp, and a small steel pin ¼ inch by 2 inches was put through the hole. The clamp was then lightly attached around the focus grip of the IR camera and a focus lever was created for fingertip control.
The utility company provided the transportation (a utility van) and a driver. The driver was a substation inspector with a great depth of knowledge. This setup was very efficient since the inspector knew right where to go and even had some input as to where some problem areas were. His instructions were "If it is a pressed-on, bolted-on or moveable connection on the115kv line we want to look at it". Also, we were to examine all 12.5kv along with the 115kv connections at the substations. Voltage regulator racks were included in the contract also.

The speed of the utility van was kept to no more than 25mph at maximum. Usually the Infrared imaging was done at about 20 mph. The trick for looking at the connections while moving was to set the IR camera at 2X zoom and point at the pole to be looked at about a ¼ mile away. As the pole gets closer move the box up as the pole approaches and continue to observe that pole until it goes by. Then immediately point the IR camera to the next pole, and repeat the process. This allows you about 5 seconds to get a really good look at any connections through the view screen of the camcorder. If any exceptional temperatures were found the driver would stop and an image would be captured. Also with this procedure, videotape could be recorded for future reference on the camcorder. By using the 2X-zoom feature on this IR camera in many cases not only the 115kv line could be scanned, but the 12.5 kV lines and poles were in the image also. That's called more bang for your buck!

When inspecting substations, the use of the box becomes very handy. All that has to happen to inspect the connections is to drive onto the site and scan from the cab using the swivel mount to scan in all directions, even at awkward angles. Using the screen on the 8mm camcorder to view images allows data to be interpreted easily and quickly without having to have your eye stuck to an eyepiece. The ability of the swivel mount to lock in position affords the IR camera to be focused and parameters set to achieve best and most accurate information.

Some substations were situated near a road that was at a higher elevation than the station. This allows the connections to be seen and scanned without entering the site (no alarms to reset). When this situation occurred, the substation was looked at from at least 3 different sides.

Data was collected on a Palm Pilot that has a scan log downloaded onto it in Excel. This is very convenient and efficient as data only has to be input once, then downloaded into a desktop report document back at the office.

Here are some examples of some images found:

poweline taps electric utility

Pivot Points 69 kV line

Hot Line Clamp 12.5kv line

public utility power line

T Tap Connections 115kv line

Pivot Points 115kv line in substation

In the course of 6 days Infrared imaging with using this new box, a total of 170 miles of power-lines were scanned. Also 42 substations and 21 voltage regulator racks were examined. A total of 52 exceptional temperature issues were discovered and recorded. As compared to the Infrared imaging that was completed during the previous year, there was a 30% increase in speed in the data collection, and 20% increase of equipment looked at, as reported by the Public Utility District.

The intention of this presentation is not to step forward with a new latest and greatest, be all do all invention that will solve all of your utility Infrared imaging needs. There have been many applications to address this situation. They range from wrapping the IR Camera in plastic and hanging out of a truck window to a full-blown, high dollar dedicated infrared utility van. Each idea and everything in between has its own merits and fallbacks.

This has been an exercise in creative thinking that hopefully stimulates your mind into finding ways to solve problems in "out of the box" ways. Because Oregon Infrared is an innovative leader in the infrared industry, creating an efficient, sturdy, re-usable, reliable, marketable, and most of all CHEAP tool to compete in the utility power-line Infrared imaging market prompted this line of creativity. This tool is an evolving idea with new improvements to be continually discovered along with its use. If I have caused you to stretch your mind in some way, then this endeavor will be considered a success.

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