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Hubbell | Greenjacket Inc. is pleased to announce that it has received permission to distribute a white paper entitled, "Under the Covers: Investigating Animal Mitigation Covers and Infrared Thermography" by Jay Bowen and Will Bauer on the issue of IR Scanning of electrical equipment while it is protected by cover-up.

At Hubbell Power Systems, Inc. (HPS), we are committed to providing our customers with outstanding service, whether in our hometowns or halfway across the world. In 2019, prior to COVID-19, two engineers from HPS spent two weeks giving presentations and training crews in Sri Lanka on the application and installation of CHANCE® helical piles and anchors manufactured by HPS. Here is their story:

To maintain worker safety while performing de-energized and grounded line maintenance, two important factors must be accomplished in the event of a fault:

1. The fault current must be cleared in the fastest available time
   
2. The current across the line worker must be limited to a safe level by creating an Equi-Potential Zone (EPZ)

Birds have no doubt been interacting with power lines and substations since the latter first appeared on the landscape. Indeed, the first record of avian collision mortality from power lines dates back to the late 1800’s, and at least one record of electrocution in North America was made as early as 1922. These incidents occur when a bird simultaneously contacts two energized components of a pole that are each at different electrical potential (referred to as a phase-to-phase fault or electrocution), or they simultaneously contact one energized component on a structure and one grounded component (referred to as a phase-to-ground fault or electrocution). These incidents not only cause injury or mortality to the birds themselves, most of which are legally protected, but they also impact the integrity of the power system.

CHANCE® Personal Protective Ground Sets are an important tool for lineworkers to use during de-energized line maintenance. The ground sets serve two purposes; one is to provide an Equi-Potential Zone (EPZ) minimizing current flow through a lineworker and the second is enabling the clearing of the fault in the fastest available time. In order to make sure the personal protective ground sets will function properly during daily use, daily inspection and periodic testing must be performed.

Although we are just starting out the new year and snow is covering the ground in much of the USA and Canada, tis’ already the season for romance and courtship for great horned owls, the largest owl in North America, and one of the earliest “spring” nesters. These majestic birds aren’t much for construction or renovation, and instead take over old nests of other birds such as crows and red-tailed hawks. To the frustration of many utilities, they sometimes choose old nests in electrical substations as their chosen spot to raise a family; these substations offer protection from the elements, a heat source (important when incubating eggs, sometimes in temperatures of -30C), and protection from most mammalian predators, thanks to the chain-link fencing. What they don’t realize is the high electrocution potential for themselves and their clumsy fledging young.  

What is Step and Touch Potential?

While performing energized or de-energized line work, there are many opportunities for a line worker to encounter differences in electrical potential. Opportunities could include working near bucket trucks, underground gear, overhead switches, or in substations. When a difference in potential occurs across a worker’s body, current begins to flow. This current flow can be very hazardous as it only takes 50 to 60mA to become possibly lethal. These differences in potential can be categorized as step and touch potential. Step potential is defined as a difference in electrical potential between a worker’s feet and touch potential can be between a worker’s hands or hands and feet.

Guy deadends are the connection between guy wire and anchor in a down guy application and must be sufficiently strong to exceed the rated breaking strength of the strand. A one-half inch diameter guy strand rated for 26,900 pounds is considered the threshold from distribution to transmission guying that would require a high-tension guy.

Hubbell Adjust-A-Grip® guy deadends offer the ease of installation and the performance that is critical for high tension terminations associated with transmission towers and antenna structures.

Energized line maintenance is a popular option for working on power lines. Two common methods for hot work include rubber gloving and hotsticking. These two work methods will utilize both primary and secondary levels of protection from energized lines and equipment. Live line barehand is another work method for working on energized lines and equipment but will not be discussed in this blog. This blog will discuss the differences between primary and secondary protection while using the rubber gloving or hotsticking work methods.

What should utilities do in a situation where they are having an animal-caused outage issue and do not know where to start when they are planning to install a new substation?

An animal-caused outage mitigation mindset must exist within all levels of a utility’s asset management process in order to completely manage the issue (see Figure 5). Utilities need to look internally to all of their processes to understand where there are examples of practices that work well and should be reinforced and also recognize areas of opportunity. Detailed in this section is a high-level review of the areas that should be reviewed, analyzed, understood, improved upon or implemented, when necessary, to support the drive toward zero animal-caused outages.