If you’ve worked in the electrical industry for any length of time, you have probably seen all kinds of creatures that have suffered a shocking demise. Mice, squirrels, snakes, birds, and even some larger “pests” cause billions of dollars in damage and economic disruption in the U.S. each year. As we prepare for the hurricane season ahead by battening down the hatches, stockpiling essentials, and fixing leaks, we’re reminded that wildlife will likely be doing the same. While humans seek safety in houses, apartments, or schools, wildlife will be seeking sanctuary in trees, down holes, and possibly in electrical enclosures.  

The design of electrical rooms and steel electrical enclosures is meant to protect power distribution systems against common outside forces like weather, human interference, and animals. These safeguards can sometimes be no match against a determined critter. It isn’t unheard of for small, wily, and aggressive animals to break through them causing extensive damage to electrical systems.

In a mission critical facility, such as a hospital or data center, this type of electrical damage can not only be problematic, it can mean incredible losses in productivity, revenue, reputation and even life. Being aware of the less-often considered causes of electrical equipment failure and system downtime is crucial, as is knowing when and how to prevent them.


Animal interference: the where and how

Starting with the smallest of creatures, mice and rats have been the likely cause of innumerable electrical system issues and failures. These rodents are attracted to the warmth and shelter provided by electrical equipment and cause damage by chewing on wires and building nests in the machinery. One notorious and potentially catastrophic incident believed to have been caused by a rat in switchgear is that of the Fukushima Daiichi power plant outage in March 2013, which lasted for more than 24 hours. The switchgear damage and resulting outage cut electricity to the cooling pools at three of the four plant reactors in addition to a common pool, putting the facility and the surrounding town in immense nuclear danger.

Another infamous outage, this time caused by a squirrel, took place in 1987 at the Nasdaq. A chewed powerline near the stock exchange’s data center in Trumbull, Connecticut, brought trading to a screeching halt for 34 minutes. Most of the time squirrels perform impressive high wire acts on powerlines without consequence, but occasionally they chew or touch the wrong thing and major outages can occur.

Raccoons can also cause more than the occasional garbage can disturbance. This was the case for 39,000 homes across Seattle last year, when power went out after a raccoon wandered into a neighborhood substation and was electrocuted. 

Snakes are also known to do their fair share of electrical damage when they slither into small enclosure openings or through conduits in search of food. Like rodents, these reptiles can bite on wiring, and in some cases, initiate small electrical fires when they lie on hot terminals and are electrocuted.

The most common of all the conniving, electrical system failure-causing critters are birds, which can damage transmission systems, power lines, and air insulated substations. While they are able to perch atop powerlines without incident, they can cause shorts and power outages when their wings or nests get too close to two different potentials or when droppings build up on exposed circuits. In 2013 in Japan, for instance, an accumulation of droppings on a substation's insulator short-circuited, disrupting power to 25,000 traffic lights and hundreds of homes.

Further, bird nests attract predators such as bears, which can cause electrical equipment damage while they search for food. While not the usual occurrence, in northeastern Alberta, Canada, bears have been seen climbing onto transmission towers, typically hunting for bird eggs.


Simple steps for protection

To protect against this ‘unconventional’ type of interference, there are several simple steps facilities and operations personnel can take:

  • Pests are attracted to overgrown vegetation and trash. Both of which can be a source of food or nest material or act as a snuggly shelter. Discourage rodents and reptiles by keeping equipment rooms and facility premises properly cleaned and sealed. Additionally, keeping traffic in and out of electrical rooms at a minimum cuts down on additional dirt and dust that may cause a hazard in other facility infrastructure, such as servers or cooling equipment.

  • Small animals can enter an opening as tight as the width of a finger, and insects can get into even smaller spaces. Conducting routine inspections of equipment and enclosures can help to identify breaks, cracks or openings that must be fixed or plugged to prevent access to the inside of the equipment. This not only prevents damage to the equipment itself but helps to protect against potential fires caused by exposed wiring or short circuits.

  • Rodents and vermin can scurry from one piece of equipment to the next via conduits. Prevent pests from becoming an issue by properly sealing conduit openings.

  • Animals and high voltage wires don’t mix. Minimize animal exposure by insulating conductors. This can be accomplished by upgrading outdoor equipment with silicone boots and tape. The insides of equipment, including bus bar and energized components, should receive similar treatment.


Going above and beyond with maintenance and modernization

Above and beyond these ‘easy’ steps, electrical and facilities personnel in mission critical industries should implement regular ongoing electrical maintenance programs to ensure the health of the electrical infrastructure. Like any engineered system, electrical power distribution systems cannot be designed and constructed to operate 100% of the time indefinitely. Even though reactive maintenance activities typically cost three to four times more, planned maintenance activities are often deferred because of high productivity objectives and tight maintenance budgets.

However, maintenance services not only help to ward against rodent intruders but also provide the support necessary to increase system reliability and lengthen the lifespan of equipment. A properly planned and executed electrical maintenance strategy is a vital component in supporting electrical workplace safety, business continuity and optimized total cost of ownership. By working with a qualified electrical engineer to perform periodic inspections and services to equipment, facilities personnel can find issues early, correct them and prevent failures before they happen. 

Regularly planned maintenance strategies can also alert personnel to the need for system upgrades. This can be basic updates to repair rot on the outside of an enclosure or the need for full replacement of old, obsolete equipment. The reality is that many facilities are built upon aging infrastructure that can hamper continuity of services, impact reliability and affect employee safety. Extensive downtime and changing code requirements can make full equipment replacement difficult. In many situations, a full equipment replacement isn’t necessary. Instead, outdated electrical equipment can be modernized with new technology, dramatically improving its performance and extending its useful life, in turn reducing required maintenance costs.


Implementing monitoring technology

There are also many technology safeguards that facilities personnel can put into place to reduce the potential for accidents, mitigate the aftereffects of certain issues and decrease the odds of unplanned downtime, animal-caused or otherwise. Physical security systems, while often associated with access control, can also offer protection from damage caused by environmental threats such as rodents and the issues they cause inside equipment and the electrical rooms that house them. Organizations should consider implementing the following security and environmental monitoring technologies to combat threats and ensure system continuity:

  • Video surveillance: A camera management system can track what is taking place in facility rooms, including who — and what — is entering and when, providing personnel with visual evidence of the cause.

  • Environmental sensors: Various types of sensors can be used to provide early warning of trouble in certain situations, such as when a door is left open to the elements or a chewed wire has ignited. User-set thresholds generate alarms when conditions such as temperature and humidity rise beyond accepted levels.

  • Electrical enclosures and electrical rooms can keep rodents and pests warm, seemingly safe and relatively undetected. Animals return the favor by doing more damage than many may realize, from tripping circuits to chewing power lines to causing major power outages. Protecting against animal infestations through basic, common sense steps, regular system maintenance and the implementation of monitoring technology can put facilities, electrical and operations personnel on the right path towards keeping electrical equipment up and running while free from animal invaders.


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