By Homer Robertson
Published Wednesday, December 1, 2010
| From the December 2010 Issue of FireRescue
Controlling the utilities at incident scenes should always be a priority. There’s a lot more to securing utilities than just going around the building turning off switches and closing valves. Just like many fireground tasks, it requires a coordinated effort by companies operating at the scene.
We rarely respond to an incident without some sort of potential electrical hazard. Just about every building fire we respond to has electrical service. Many vehicle accidents involve downed power lines or damaged electrical distribution equipment, such as power poles or above-ground transformers. Dangers even exist while working wildland incidents, where live power lines may be on the ground and hard to detect because of smoke conditions or vegetation cover.
The point: Due to the prevalence of electrical hazards we encounter in our jobs, we need to train on how to recognize and safely handle such hazards—and know when to have the discipline to leave them alone. This month’s Quick Drill will focus on electrical fireground safety.
Structure Fire Electrical Safety
There are plenty of reasons you need to control the electrical power at structure fires. As the fire systematically destroys the structure and firefighters open up walls and ceilings, electrical wires become exposed, increasing firefighters’ chances of becoming shocked.
Being able to quickly control the power minimizes the possibility that crews working inside the building will touch energized wires that could shock them. Shutting off the power may also help to stabilize the incident if the problem stems from a malfunctioning electrical appliance or distribution system, such as light fixtures.
When it comes to training crews on how to handle electrical utility control, things get interesting. There’s a wide range of views about correct operational procedures for how to handle cutting power. Some departments are very aggressive, allowing their crews to go as far as pulling meters and cutting the loops going to the house, while others limit efforts to only shutting off breakers in the panel. Some departments require personnel to leave everything to utility company personnel. Therefore, you must know your department’s standard operating procedure (SOP) and train on it often.
Electrical dangers exist outside the building, too. If the electrical service is being fed from overhead lines, there’s always a chance that flame impingement can burn them off the building, leaving a live wire on the ground. This can be dangerous because in heavy smoke conditions or with an SCBA facepiece on, it can be difficult to see fallen wires. Don’t be complacent about “wires down”—you just never know when someone will walk on them.
A few things you can do to improve the safety of the operation when encountering wires down:
- Don’t try to move them to a safer location. Leave that to the professionals.
- When you encounter a downed live wire, take precautions to keep others off of it. Notify command so others on the fireground are informed. Stay with the power line to act as a safety.
- If you can, form a barrier around the danger area using barricade tape or traffic cones so that memebers operating in the area can see there’s danger—this is especially helpful when noise levels are high and a verbal warning may go unnoticed.
Ladders & Electricity
The ladder is one of the fire service’s earliest and most used tools. We still use it on a daily basis to accomplish a wide range of jobs. While still in use in some areas, the wooden ladder isn’t used as extensively as it once was. Fiberglass ladders are used in some locations, but the aluminum ladder is the most commonly used fire service ladder used today.
Ladders and electricity just don’t mix—especially the aluminum type. But in the stressful conditions in which we work, where people are in a hurry to get the job done and visibility is poor, the possibility of coming in contact with a live wire while setting a ladder to a window or rooftop is pretty high.
When training on basics such as ground and aerial ladder placement, always stress the importance of looking for overhead obstructions like electrical lines. Also, take time to review the different types of overhead cables other than electrical, like cable TV and phone lines, and note their size, appearance and height on the pole.
Another important training point: The ladder doesn’t have to come in contact with the power line to become energized. There’s an electric force field around electric lines. As the relative humidity in the air increases and the voltage in the line increases, the size of the force field increases. Because of this, most training manuals advise keeping both ground and aerial ladders a minimum of 10 feet away from electric lines.
Although this article focuses on structure fire scenes, the importance of electrical safety should always be reinforced during any type of training where ground or aerial ladders are used. There have been many near misses, accidents and even deaths associated with training or apparatus inspection outside the station when ladders came in contact with power lines.
Use the Pros
When dealing with electrical hazards on the fireground, use the professionals every time you can. Your local electrical provider deals with electrical issues every day; there’s probably nothing you can throw at them that they haven’t already dealt with. They also have training and information that we just don’t have—for example, knowing whether the power supply has to be shut down at the pole or in a sub-station away from the scene.
Most utility providers have positive relationships with the fire service and are willing to train your department to recognize and handle some types of electrical emergencies. They’re also willing to respond to the scene to assist. Think about it: Your customer at a fire is also a customer of the utility provider. They want to help their customers just like you do.
When the responding utility provider has controlled the incoming power supply, they should notify the incident commander. Always take time to verify that the power has been shut off before proceeding. It’s always a good idea to treat any downed wire as if it were live until you know for sure.
A Note on Above-Ground Transformers
With more and more of the electrical distribution system going underground these days, we see a lot more above-ground or pad-mounted transformers. We often encounter such units at extrication calls, where they may have been damaged by cars. You only need to remember one thing, “If it’s damaged, it’s dangerous.” This is truly a situation in which your local power provider needs to be called.
Even if you have patients that need to be treated or extricated from the vehicles, you may have to wait for the go-ahead from responding power company personnel before starting to work.
A Final Word
You can write pages about fire service electrical safety and still not cover everything, but the key to safety is awareness, good policies and training that addresses electrical safety on the fireground and during training.
Drill 1: Hit the Books
- Review your department SOPs on controlling electrical utilities at residential and commercial buildings.
- Discuss your department’s operations when “lock-out/tag-out” procedures are in place.
- Review your department’s best practices for correct placement of apparatus at broken power poles and downed energized power lines.
- Discuss the correct use of ground and aerial ladders around power lines.
Drill 2: Call in the Pros
Ask your local power company to conduct an electrical awareness program for your department. The program should cover:
- When should the fire department attempt to control utilities and when should they not?
- Dangers of downed power lines and damaged power poles, and minimum safe distances to maintain from each.
- Handling incidents involving above-ground transformers.
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