High voltage transmission and distribution lines and utility substations, like any other electrical equipment, are vulnerable to failure. Put us to work for you to inspect your equipment on a regular basis…

High Voltage Transmission Line Infrared Surveys

Aerial Transmission Line P/PM

Flying over transmission lines is obviously the most efficient and effective way to find problems, which is why we use aerial infrared. The infrared cameras that we use for aerial infrared thermographic surveys have six (6) times the resolution of most modern infrared cameras. Because of the high-resolution, this type of camera can be mounted in a fixed-wing aircraft allowing the infrared thermographer to quickly fly over transmission lines. The problem areas are found and the exact coordinates are marked with an integrated signal processor which displays on the screen and is digitally recorded along with the infrared image, displaying the date, time (to the millisecond), altitude, mission code, Latitude/Longitude (differential) and speed over ground. Detecting electrical faults on high voltage electrical transmission lines is fairly easy and can be accomplished rapidly from a light aircraft, however, even from short distances, accurate temperatures of electrical faults are impossible to measure [quantify]. There are several problems associated with temperature measurement from the air. These include spot size to target distance ratios, reflection of the objects surveyed, having a sufficient load on the line at the time of the survey, among others. This is why you need our scientific approach.Read more about quantitative temperature measurements on transmission lines…


Substation Infrared Surveys

We have found that temperatures alone cannot be used to determine if equipment is likely to fail. The accurate evaluation of a distribution line or substation depends mostly on the knowledge of the person performing the inspection. This person must have the knowledge of how the equipment operates, how it is constructed, and what its function is in the operation of the substation.


There are at least four different types of transformers in a substation, which operate at different temperatures, depending on their functions and load requirements.

  1. Current transformers are solid and are designed to reduce currents by a percentage.
  2. Potential transformers may be solid or oil-filled. They reduce voltage and are used to measure usage of power. Higher temperature readings on a current transformers are normal as compared to potential transformers. Even a person that has worked with this type of equipment for years would not know this unless he had spent many hours infrared surveying, taking readings and knowing the equipment.
  3. Service transformers feed equipment in the station such as lights, chargers, fans, etc. Temperatures on these types of transformers depend on the equipment they service and whether it is operating at the time of the infrared survey.
  4. Power transformers are the reason that the substation exists. Load percentages, fluid levels, and the characteristics of oil circulation in power transformers all have an effect on their temperatures. The infrared thermographer must know what to look for and how to report findings. An increase of three degrees C in one area of the transformer may be more important than a thirty-degree increase in another.


These devices switch from one contact point to another several times in a day. This is the most likely piece of equipment to explode in a substation when personnel are in the station, switching loads. Because the contact point is inside of the tank of the regulator, it is very important to carefully inspect this piece of equipment and record the readings. The heat could be coming from several inches inside the tank and since it is surrounded by gallons of oil, a slight rise in temperature could be a serious problem. An accurate record must been kept of the findings during maintenance of regulators, especially ones that have been found to have high temperatures. Some manufacturers of regulators have placed copper and aluminum wire in the same connector. These regulators have a high rate of failure and have caused millions of dollars in damage. When sub-stations are inspected, this equipment should be compared to the model of equipment known to have this condition and reported.

High Voltage Distribution Line Infrared Surveys

Because they are smaller, lower to the ground, and often run through populated areas, high voltage electrical distribution lines are much more difficult to see against all the thermal clutter on the ground such as trees, street lights, people, animals, etc., than transmission lines using aerial infrared techniques.

noneDetecting electrical faults on high voltage electrical distribution lines can be accomplished rapidly from a moving scanning vehicle.  Our thermographers can help your utility by scanning the lines and substations quickly from one of our fully-equipped scanning vehicles. Using your system maps, UtilityScanIR™ experts quickly & efficiently drive down the lines of your system with state-of-the-art navigation and imaging systems and record all imagery and GPS position data onto digital storage. When a problem is discovered, we mark the area on the map and immediately produce reports detailing the fault information so that repair crews can be mobilized to remedy the problem.