Transcript 1 Tools and Electrical

Tools and Electrical
Disclaimer: The content in this slide show has not been reviewed by the Department of Labor and Industries for accuracy and has been
provided as “sample” curriculum only. Each Authority Having Jurisdiction must design, take authority of, and responsibility for, the
actual training done by the Department. Local SOPs/SOGs, State regulations, and Federal laws may impact the material
suggested. The Department of Labor and Industries and Washington State Fire Chiefs Association takes no responsibility for the
outcomes or use of these training samples.
Learning Objectives
•
Firefighters will use hand power tools that are grounded,
inspected, guarded, and used properly.
•
Firefighters will identify injuries and fatalities related to
electricity, including shocks and burns.
•
Firefighters will identify potential sources of electrocution and
ways to prevent injuries in buildings, with tools, cords, at
emergency scenes and by downed power lines.
WHY WE CARE
•
59- year-old male career Captain multiple fractures in his right
thumb and incurred significant heart damage.
•
36-year-old male career Captain (the victim) was electrocuted
•
40-year-old male career Fire Captain (the victim) was
electrocuted after coming into contact with a 12,400-volt
overhead powerline
•
volunteer fire fighter (the victim) was electrocuted while fighting
a grass fire
WAC, Standards and
FF 1 - FF2 Skills
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WAC 296-305-05002 (11) Firefighters shall not cut the electrical drip loop providing
power to the structure nor pull the electrical meter.
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WAC 296-305-06008
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NFPA 1500
Electrical
Standard on Fire Department Occupational Safety and Health, prepares firefighters to safely
control the hazards they face, including arc flash. Firefighters entering areas with arc flash
potential must be aware of the danger and the protocol that must be followed. Exposure to
shock hazards and electrocution risks are common and real. Personal protective equipment
for arc flashes and arc blasts are similar to firefighter bunker gear.
•
NFPA 70E
Inspections of potential areas which could result in arc flash are vital. NFPA 70E, article
130.3 states: “A flash hazard analysis shall be done in order to protect personnel from the
possibility of being injured by an arc flash. The analysis shall determine the flash protection
boundary and the personal protective equipment that people within the flash protection
boundary shall use.”
•
IFSAC FF2
6-5.4 Maintain powerplants, tools and lighting equipment
Power Tool Requirements
Requirements
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Have a three-wire cord
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Be double insulated
GROUNDING
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Grounding creates a low resistance path from a tool
to the earth to disperse unwanted current.
•
When a short or lightning occurs, energy flows to the
ground, protecting you from electrical shock, injury and
death.
•
Tools plugged into improperly grounded circuits may
become energized
•
Broken wire or plug on extension cord
GROUND TOOLS AND
ELECTRICAL
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Ground power supply systems, electrical circuits,
and electrical equipment
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Frequently inspect electrical systems to insure
path to ground is continuous
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Inspect electrical equipment before use
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Don’t remove ground prongs from tools or
extension cords
•
Ground exposed metal parts of equipment
USE GFCI
GFCI (ground-fault circuit interrupter)
•
Protects you from shock
•
Detects difference in current
between the black and white wires
•
If ground fault detected, GFCI shuts
off electricity in 1/40th of a second
•
Use GFCI’s on all 120-volt, single-phase,
15- and 20-ampere receptacles,
or have an assured equipment
grounding conductor program.
INSPECT TOOLS
Frequently inspect tools for
•
Broken parts
•
Missing guards
•
Loose handles
•
Broken cords
PERSONAL PROTECTIVE
EQUIPMENT
Correct PPE
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Eye Protection
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Hearing Protection
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Respiratory Protection
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Gloves
•
Helmets (overhead hazards)
TOOL SAFETY TIPS
Know how to use your equipment
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Use gloves and appropriate footwear
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Don’t carry a tool by the cord
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Don’t yank the cord to disconnect it
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Disconnect when changing accessories such as blades & bits
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Remove damaged tools from use
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Store correctly in dry place when not in use
Learning Objectives
Firefighters will identify injuries
and fatalities related to
electricity, including shocks and
burns.
CAUTION:
The following slides
contain graphic pictures.
ELECTRICAL INJURIES
Types of Electrical Dangers:
Direct:
• Electrical shock
• Burns
Indirect :
• Falls after the “jolt”
• Other worker impacted
ELECTRICAL SHOCK
Electrical Shock
An electrical shock is received
when electrical current passes
through the body.
You will get an electrical shock if
a part of your body completes
an electrical circuit by…
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Touching a live wire and an
electrical ground, or
•
Touching a live wire and another
wire at a different voltage.
This worker fell and grabbed a power line to catch
himself. The resulting electric shock mummified
his first two fingers, which had to be removed. The
acute angle of the wrist was caused by burning of the
tendons, which contracted, drawing the
hand with them.
BURNS
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Most common shock-related injury
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Occurs when you touch electrical wiring or equipment that is
improperly used or maintained
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Typically occurs on hands
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Very serious injury that needs immediate attention
This worker was shocked by a tool
he was holding. The entrance
wound and thermal burns from the
overheated tool are apparent
Same hand a few days later, when massive subcutaneous
tissue damage had caused severe swelling (swelling usually
peaks 24-72 hours after electrical shock). To relieve pressure
which would have damaged nerves and blood vessels, the skin
on the arm was cut open.
ELECTROCUTIONS
Causes of Electrocution
Fatalities
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Contact with Overhead
Power lines
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Contact with Live Circuits
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Not following Lock/
Tagout procedures
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Poorly Maintained
Extension Cords
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Defective Power Tools
This victim contacted an overhead power line
while working from an aerial bucket.
NOTE: Most aerial equipment is NOT insulated.
HOW TO CONTROL
ELECTRICAL HAZARDS
Control
Electrical accidents are caused
by a combination of three
factors:
•
Unsafe equipment
and/or installation,
•
Workplaces made unsafe
by the environment, and
•
Unsafe work practices.
Responding Safely
ARCH FLASH
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Typical Structure Fire =
1100-1800 degrees over
several minutes of time
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Primary Arch Flash =
>11,000 degrees in 1/10
of a second
HAZARD EXPOSED ELECTRICAL PARTS
Cover removed from wiring or breaker box
Safety BASICs
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As much as 80% of all electrical injuries are burns resulting
from an arc-flash and ignition of flammable clothing
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Arc temperature can reach 35,000°F - this is four times hotter
than the surface of the sun. Fatal burns can occur at distances
over 10 ft.
•
Over 2000 people are admitted into burn centers each year
with severe electrical burns
statistics: Progress Energy
Volts vs. Amps
Amperage (amount) of current is the danger during electrical contact.
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The Human Body can withstand 1000’s of Volts
•
•
1/5 of 1 amp or 5ma can stop the Heart
•
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Stun Guns = 50k volts (No Amps)
This is about what a household night light carries.
More people are killed from 120/240 Volts than any other voltage.
statistics: Progress Energy
Safety BASICs
Shock
Current, Not Voltage causes Electric Shock
mA
Affect on Person
0.5 - 3
- Tingling sensations
3 - 10
- Muscle contractions and pain
10 - 40
- “Let-go” threshold
30 - 75
- Respiratory paralysis
100 - 200
- Ventricular fibrillation
200 - 500
- Heart clamps tight
1500 +
- Tissue and Organs start to burn
Note: Reaction will vary with frequency and time of exposure
statistics: Progress Energy
Safety BASICs
Shock
Human body resistance (hand to hand) across the body is about
1000
Ohms Law: I = V / R (Amps.)
I = 480 volts / 1000
= 0.48 amps (480 mA)
The National Electrical Code® considers 5 mA to be the safe
upper limit for children and adults.
statistics: Progress Energy
Safety BASICs
Shock
Current passing through the heart and lungs is the most serious
photo credit: Progress Energy
Shock Resistance Table
Shocking!
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Over 30,000 non-fatal electrical shock accidents occur each
year
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Over 600 people die from electrocution each year
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Electrocution remains the fourth (4th) highest cause of
industrial fatalities
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Most injuries and deaths could be avoided
statistics: Progress Energy
Things May Not Be As
They Appear
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Don’t assume that because a wire isn’t sparking that it isn’t
energized. A downed power line can still be hot.
•
Don’t assume that a phone or coaxial cable line isn’t energized.
It’s possible that a few spans away, an energized power line
could be touching the phone or cable line, energizing it as well.
And there’s always the possibility that what you think is a phone
line is really a power line. BOTH CATV AND PHONE LINES
CAN CARRY 7200 VOLTS!
•
There could be hazards that you can’t see: a line down that is
concealed by a tree, bush or brush; an energized line down a
few spans away; and other hazards could still be present.
statistics: Progress Energy
Ladders and Other Lifts
Before raising or extending any kind of ladder, metal pole, or
other equipment capable of reaching a power line, check in all
directions for power lines. Be careful while carrying or positioning
any kind of ladder, tool, equipment, or extension and keep them
well away from energized overhead power lines, especially the
weather head or service drop.
Look up and live!
statistics: Progress Energy
Fires and Electricity
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Utilities must de-engergize buildings and downed
power lines
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Never pull a meter or cut wires
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A pulled meter does not guarantee there are no
energized wires in the building
Service Wires
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On structure fires, do not cut
service wires or electric drops
leading to the building. Although
service wires are low voltage,
cutting them can still cause
electrocution death.
•
Cutting a wire does not always deenergize it. A downed wire can
pose serious dangers to the public
and fellow workers in the area.
photo credit: Progress Energy
Electric Meters
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Only power company
employees should ever
attempt to pull the meter.
•
It is only a measuring device
and not a switch.
•
It could short out at the base
and possibly cause burns,
eye damage, or even an
explosion.
photo credit: Progress Energy
Beware of “Back-Feed”
Generators are fairly
inexpensive.
After power outages,
many people run
generators.
Proper installation
can save lives!
Vehicle Accidents and
Downed Power Lines
Most often the first
responders are the
Police or Fire
Departments
Downed Power Lines
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Extremely hazardous
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Appearance can be
deceiving
•
Beware of Ground Gradient
High Voltage Shock
Effects
Insulated cutters, but inappropriate
tool to use for high voltage.
Only High Voltage Hotsticks, with
Voltage-rated Gloves can be used
for this work.
Qualified Electrical Workers only.
Result:
Electrocution.
photo credit: Progress Energy
High Voltage Shock
Physical Effects of Electrocution
photo credit: Progress Energy
High Voltage Shock
Entry point of High Voltage
photo credit: Progress Energy
High Voltage Shock
Arcing Effects - Body to Grounded Conduits (2)
photo credit: Progress Energy
High Voltage Shock
Effects - Arcing to Grounded Conduits (2)
photo credit: Progress Energy
High Voltage Shock
Arcing Effects - Body to Grounded Conduit
photo credit: Progress Energy
High Voltage Shock
Blowout Effects
Exit points (4)
Thru the right thumb,
left elbow, abdomen,
and pelvic area; where
High Voltage Arc blows
out… completing the
circuit to ground.
photo credit: Progress Energy
High Voltage Shock
Entry and Exit Wounds
photo credit: Progress Energy
Learning Objectives
Firefighters will identify potential sources of
electrocution and ways to prevent injuries in
buildings, with tools, cords, at emergency
scenes and by downed power lines.
DAMAGED CORDS
Cords can be damaged by
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Aging
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Door or window edges
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Staples or fastenings
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Abrasion from adjacent materials
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Activity in the area
Improper use can cause shocks,
burns or fire
This fire was started by a
damaged extension cord
OVERHEAD POWER LINES
Keep Equipment 10’ feet
away from Power Lines.
Increase distance with
increased kilovolt.
PREVENTING ELECTRICAL
HAZARDS - PPE
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Proper foot protection
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Rubber insulating gloves, hoods,
sleeves, matting, and blankets
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Hard hat (insulated nonconductive)
PREVENTING
ELECTRICAL HAZARDS
Proper Wiring and Connectors
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Use and test GFCI’s
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Check switches and insulation
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Use three prong plugs
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Use extension cords
only when necessary
& assure in proper
condition and right
type for job
•
Use correct connectors
TRAINING
Train members working with electric equipment in
safe work practices, including:
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De-energize electric equipment before inspecting or repairing
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Using cords, cables, and tools that are in good repair and have
not been modified from their original use and purposes
•
Use appropriate protective equipment
SUMMARY
Tools and Cords must be:
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Double Insulated
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GFCI
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Inspected Regularly
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Fixed and safe before Proper Use
Prevent Electrocution by keeping:
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Cords in good condition
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At least 10’ from Power Lines
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Shoes with Rubber Soles