Today's utilities face the challenge of upgrading aging infrastructure and improving power reliability for their utility's customers. In Alberta, Canada, AltaLink's transmission line field crews are a key part of the AltaLink team tasked with serving more than 85% of Alberta's population. As such, it is essential for the asset management and linemen team to find ways to minimize outages and increase customer satisfaction.

One of the ways AltaLink has improved reliability is by protecting its substation equipment against wildlife intrusions and costly outages. Six years ago, AltaLink partnered with Cantega Technologies to install customized, protective precise-fit cover-ups on substation equipment.

The company has seen a marked improvement in reliability, reducing both the frequency and duration of outages to customers. In fact, the program has resulted in a measureable improvement in the System Average Interruption Frequency Index (SAIFI) and the System Average Interruption Duration Index (SAIDI) of up to 2.7% and 7.7%, respectively.

Testing the Product in the Field

In the beginning, AltaLink was seeking an improved method for mitigating animal- and bird-caused outages. AltaLink's engineers, safety team and field crews worked with Cantega to develop a way to cost-effectively custom fit the product to substation equipment that must be covered to reduce these power disruptions.

For two years, AltaLink tested prototypes and suggested modifications. Today, the utility's engineering standards identify where they need to target cover-up for insulators and bus-type gear. For example, AltaLink tries to protect those areas where wildlife can flash across two points such as the top of transformers or regulators.

Customizing Cover-Ups

AltaLink tried the one-size-fits-all products in the past, but these cover-ups inevitably left gaps and spaces. As a result, animals and birds could still contact the equipment, leading to outages and equipment damage. In comparison, however, Greenjacket measures the exact dimensions of the equipment that will be protected.

Through a patent-pending system that includes photogrammetry, Cantega is able to take images of energized electrical equipment. The company then creates custom fit cover-up molds for the locations that must be covered on site. These covers fit precisely from ⅛ inch to 1/16 inch, eliminating contact points, which pose as risks for causing outages.

Because many of AltaLink'spieces of equipment are the same size and configuration, the substation technicians can use the same molds for multiple sites. If they have a unique size or shape, then they can call upon Greenjacket, who will take a few hours to digitally sample the equipment and make a custom mold.

Installing and Maintaining Cover-ups in the Field

AltaLink now uses Greenjacket as the new standard for new and existing sites that must be retrofitted. The utility primarily has installed the product in the lower-voltage substations, where the wildlife can more easily cause outages because of the narrower space between equipment.

At the start, Greenjacket/Cantega handled all of the work for the installations, but AltaLink now calls upon a few installers who are qualified to install the cover-ups at the substation.

Greenjacket/Cantega is now introducing tools to allow energized installation of the covers. Because it is a precise-fit product with hot line tool “snap-on” installation design incorporated, it is very effective for the substation technicians to install with hot line tools.

The cover-up is made from a polyurea material, which has been tested to the IEEE 1656 industry standard for bird and animal cover-up. As a result, AltaLink has not had to do any maintenance on the cover-up in the last six years. If the technicians do need to remove them to do maintenance on the substation, however, they can unlock the connectors, remove the molds, perform the work and then reinstall them quickly.

AltaLink now has the product in more than 70 locations and plans to retrofit about five to 10 substations per year. As a result, the company has seen a 95% reduction in wildlife-caused outages.


Dennis Frehlich (dennis.frehlich@altalink.ca) is the executive vice president and COO of AltaLink. He has been with the company since 2002 and been in the industry for 25 years on the transmission side of the business. He has been in senior leadership for the last 15 years.

Companies mentioned:

AltaLink | www.altalink.ca

Cantega Technologies | www.cantega.com