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FDNY HOMEPAGE NEWSLETTER-January-February-March 2002 Electricity
JANUARY-FEBRUARY-MARCH NEWSLETTER BY VINCENT DUNN Fire ground electrocution To survive firefighting,
firefighters must know how other firefighters have died fighting fires.
Electrocution is one cause of fire ground death. Causes of firefighter death: 1. Stress 2. Falls, falling
objects in contact with electricity and other dangerous objects 3. Products of
combustion 4. Structural collapse Firefighters electrocuted while fighting fires are often
using metal ladders or metal tools near line electricity. One firefighter was
electrocuted when repositioning a metal ground ladder. Three
firefighters were carrying the ladder vertically; one slipped on ice, causing
the ladder to sway and the tip hit a nearby overhead electric wire spanning street utility
poles. Although electric power shut off would not have prevented
this firefighter's death, cutting off electric power to a burning building is
an important safety procedure. Fire officers should know who, when, where and how to shut
off electric power to a burning building. Who When there is a working structure fire, an electrician from
the local utility company should respond and report to the officer in
command. The utility company employee should be equipped and know how to remove
power to a burning building by disconnecting wires from a utility pole or
street shut off. The utility company employee does this upon
orders of the chief in charge. When a utility company cannot guarantee 24-hour
availability to respond to fires, they must train firefighters to do the
job. When Generally at a structure fire, electric power should remain
on for as long as safety permits. Electricity provides power for
lights, which assists search and rescue operations. It keeps fire pumps running
for fire extinguishment and elevators operated by firefighters for evacuation.
However, there are certain times during a fire or emergency operation when
electric power should be immediately removed to protect firefighters and
trapped victims. 1. Electricity should be cut off before overhaul
starts. Normal current in a residential building can kill firefighters. During
overhaul, walls, ceilings and floors are sometimes broken open in order to search for
hidden fire. Metal tools can come in contact with electric wires behind these
walls and ceilings. Firefighters standing on a wet floor in a
burned out room can get a metal tool entangled in a live wire. This can cause
the firefighter to be electrocuted or severely shocked. So, after a fire is
extinguished and overhaul is about to start, electric power should be shut off. 2.When electricity is the source of heat causing the fire,
power must be immediately cut off. Also, if a victim is being
electrocuted, power must be removed from the wire or appliance threatening the trapped
person. To handle this type of fire or emergency, firefighters must be trained
to safely shut off electricity to residential buildings. Utility
companies cannot respond quickly enough to do the job. 3.Explosions and structural collapse rip open walls,
ceilings and floors of a structure. Live electric wires are threaded throughout
the rubble, hanging dangerously in midair and laying around the ground. A
collapse search and rescue plan must be put into action. This plan must
include: safety survey and reconnaissance, surface search and rescue, void search,
selected debris removal and general rubble removal. One of the most important
parts of the first step of the collapse rescue plan is to shut off all
the utilities such as water and electricity. Shutting off electric power
can save the lives of searching firefighters and trapped victims in the collapse
rubble. Where The fire officer ordering power shut off must limit the area
of electric power loss to as small an area as possible; increasing the area
affected as needed: one room, one apartment, one floor, one building
section. Also, the electric power should be cut off as near to the area
of operations as possible. For example, first consider removing apartment fuses or opening
circuit breakers. If this is not possible, consider shutting off the
power from the electric panel box in the basement. Only utility company
employees or trained firefighters would be permitted to pull meters outside a
residence or cut electric wires. Firefighters ordered to remove electric
power should know the hazards they face. There are several dangers
firefighters are exposed to when cutting off electric power to a structure. Firefighters
sent to basements to pull the switch on an electric panel box have been
severely burned in several ways. Searching for an electric panel box in
the dark or in smoke, firefighters have walked into live electrical equipment.
When the cover to the electric equipment has been left open or removed, firefighters
have been severely burned or electrocuted. Also when you pull the switch
to open the circuit, if the cover to the electrical panel is open or
removed, arcing or an electric flame can explode outward and burn the
firefighters standing in front of the panel box. How To protect yourself when pulling a switch to an electric
panel box, use a light to locate the box; make sure the panel box cover is
closed, and stand away from the electric panel box. After the switch is
opened, an arc explosion inside the enclosed box can blow the cover or panel
off the wall. Eye shields should be donned or an SCBA facemask worn. Meters
outside private dwellings should only be removed when life is threatened and
the inside service switch box in the basement cannot be reached because
there is a danger of arcing during the meter removal from the panel.
Whenever electric current is interrupted, an arc can be produced. This
is an explosion, like a flash of blinding light. Hot sparks and
splattering molten metal may accompany the arc explosion. Safety precautions recommended
when pulling meters outside a private dwelling are: protective lineman gloves,
eye shields, standing on rubber matting or dry wood surfaces and
keeping the face and body away from the meter in case there is an arc. Electrocution If an electric panel box, in a basement or an outside meter
is not available to cut off electric power, electric wires entering the
residential building may have to be cut. This is extremely dangerous.
Only a utility company employee or trained firefighter should do this. A study by the National Institute for Occupational Safety
and Health revealed how incidents of electrocution occur most often around
normal house current 110-120 volts. The study also revealed
"many personnel did not realize that contact with 110/120 volts could
cause death." The following safety precautions must be taken by utility
company personnel or trained firefighters when cutting electric wires: 1. Wear rubber lineman
gloves at all times 2. Wear eye protection
at all times 3. Use lineman-cutting
tool 4. Cut one wire at a
time 5. Stand on a dry
non-conductive rubber mat or dry wood surface. Have a person stand by for assistance Lessons Learned Fire departments must establish
preplanned emergency responses with local utility companies and train
firefighters to do the electric shut off procedures. Departments must provide trained
firefighters with required personal protective equipment: rubber nonconductive
mats, lineman gloves and lineman insulated cutting tools. If utility
companies do not respond, and we don't train our firefighters to shut off
electricity, then untrained firefighters may risk their lives attempting an extremely
dangerous act to save lives. Questions for Newsletter: 1. Which
is not a leading cause of Firefighter deaths? A.
Stress B.
Falls C.
Products of combustion D.
Strains and sprains
Answer_______ 2. When should the incident commander order electric shut off? A.
Before overhauling begins B.
After overhauling ends C.
Before leaving the scene D.
Never Answer_______ 3.Most firefighters are electrocuted by what voltage?
A.
110-120 voltage B.
220 voltage C.
high voltage D.
None of the above Answer _______ 4.True or false Utility companies should respond to every working fire
. Answer_______ 5. Electric wires should be cut by?
A.
Utility workers B.
Utility workers and/or trained firefighters C.
Chief officers only D.
None of the above Answer_______ Answers:
1. D; 2. A; 3. A; 4.True; 5. B