Transcript Electrical Safety Program - E Light Safety, Training and

Electrical Safety Program
Refresher Training
In Compliance with NFPA 70E, 2009
Standard for Electrical Safety in the Workplace
Definition of Hot Work
• Any work on electrical equipment, circuits,
devices, systems, or any other energized
part(s) where an employee is required to
deliberately, or could accidentally, place any
part of his body, tool or material into or
around such electrical devices where the
voltage has been deemed to be in excess of 50
volts.
Why 50 Volts?
• OSHA and NFPA 70E have determined that the
threshold for dangerous electrical potential is
50 volts.
• WHY?
• The average human has 10,000 ohms of
resistance in our skin.
• Currents of .005 amperes can be fatal.
• Ohms law: 50 volts / 10000 ohms= .005 A
Study of Electrical Accidents
• Study was done base on serious electrical
accidents that occurred to professional
electricians during the discharge of their
professional duties.
• An electrical accident was defined as an
accident that was caused by contact or close
proximity with electrical energy that was
discharged in a manner not compliant with
the circuit or system’s design.
Study of Electrical Accidents
• A serious accident was defined as any accident
that resulted in 6 months lost time up to and
including a fatality.
• There were 178 accidents that fell into this
category in 1998.
Category Break Down
Distribution Equipment:
4%
Overhead Power Lines:
3%
Devices Mounted Below 8’: 31%
Devices Mounted Above 8’: 59%
Other Accidents:
3%
Interesting Statistics
• 90% of the accidents occurred while doing
every day electrical tasks
• 81% of the accidents occurred to electricians
with 8 plus years of experience.
Ask yourself why the majority of
these serious accidents occurred
to experienced electricians.
The Hazards of Electricity
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Electrical Shock
Burns
Arc Blast
Arc Flash
Electrical Shock
• Short Term Effects
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Heart Failure
External Burns
Internal Burn
Cellular Degradation
Autonomic System
Failure
– Ventricular Fibrillation
– Muscle Contractions
• Long Term Effects
– Nervous system
disorders
– Heart Damage
– Heat Murmur
– Brain Chemical
Imbalance
– Muscle Ticks
– Muscle Damage
Effects of Current on the Body
• Five primary factors affect the severity of the
shock a person receives when he or she is a
part of an electrical circuit:
– Amount of current flowing through the body
(measured in amperes).
– Path of the current through the body.
– Length of time the body is in the circuit.
– Contraction position of the heart
– Chemical cycle of the body
Safety BASICs
TM
Shock
(A) Touch Potential
(B) Step Potential
(C and D) Touch / Step Potential
Current passing through the heart and lungs is the most serious
Other Factors
• The voltage of the current.
• The presence of moisture in the environment.
• The general health of the person prior to the
shock
• The resistance of the person shocked
Safety BASICs
TM
Shock (Resistance Table)
Condition
Resistance, (ohms)
Dry
Wet
Finger Touch
40,000 to 1,000,000
4,000 to 15,000
Hand Holding Wire
15,000 to 50,000
3,000 to 6,000
Finger-Thumb Grasp
10,000 to 30,000
2,000 to 5,000
Hand holding pliers
5,000 to 10,000
1,000 to 3,000
Palm Touch
3,000 to 8,000
1,000 to 2,000
Hand around 1 1/2 Pipe
1,000 to 3,000
500 to 1,500
Two Hands Around 1 1/2 Pipe
500 to 1,500
250 to 750
Hand Immersed
200 to 500
Foot Immersed
100 to 300
Human Body, internal,
excluding skin
200 to 1,000
This Table was compiled from data developed by Kouwenhoven and Milnor
Effects of Current
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Current level (in milliamperes) and Probable effect on human body
1 mA Perception level. Slight tingling sensation. Still dangerous under certain
conditions.
5 mA Slight shock felt; not painful but disturbing. Average individual can let go.
However, strong involuntary reactions to shocks in this range may lead to injuries.
Ventricular fibrillation can occur at this level.
6-30 mA Painful shock, muscular control is lost. This is called the freezing current
or "let-go" range.
50-150 mA Extreme pain, respiratory arrest, severe muscular contractions.
Individual cannot let go. Death is possible.
1000-4300 mA Ventricular fibrillation (the rhythmic pumping action of the heart
ceases.) will occur. Muscular contraction and nerve damage occur. Death is most
likely.
10,000 mA Cardiac arrest, severe burns and death almost certain.
Energized Work
• Is usually preformed on equipment that is not
protected by GFCIs.
• Even a 15 ampere circuit break will not trip
until an overload of 15001 milliamperes is felt
in the human body.
• Far Beyond the Survival Current.
Types of Burns
• First-degree burns include only the outer layer of
skin. The skin may be red. The skin may also hurt
when touched. These are mild burns and usually heal
in a few days.
• Second-degree burns are deeper and more severe.
Blisters may form on the burned area. The skin feels
very tender when touched. This burn takes about 2
weeks to heal.
• Third-degree burns are the deepest and most
dangerous. The skin is tough or leathery. It may look
white, brown, black, or red. You may not feel
anything when the burned skin is touched
Effects of Electrical Burns
• Immediate Effects
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Pain
Deformity
Nerve Damage
Oral Cavity Damage
Genital Damage
• Long Term Effects
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Bone Damage
Nerve Damage
Organ Failure
Teeth and Gum Failure
Arc Blast and Flash
• The third hazard of electricity is the most
powerful and dangerous, yet the least talked
about in electrical circles.
• It was not officially recognized until 1995.
• It was not widely studied until 1997.
• We now understand it very well, perhaps, too
well.
Arc Blast
• What is an electrical arc.
– Current flowing through an area that was once
filled with air.
• What causes an arc? HEAT
– Electrical conductors coming into contact and
breaking contact
– Electrical conductors coming into close contact
– Environmental conditions
Effects of Arc Blast
• An electrical arc burns at between 20,000 and
32,000 degrees F.
– That is twice the center of a nuclear explosion.
– That is four times the surface temperature of the
sun
• The average electrical arc lasts for 4-6 cycles
from beginning to end.
Expansion of Material
• Matter changes shape with temperature as it goes
from solid to liquid to gaseous forms.
• Water expands 4 times when it goes from liquid to
gaseous form.
• Copper expands nearly 67,000 times in volume when
it goes from solid to gaseous form.
• This happens in less than a 10th of a second.
Shock Wave
• Due to this expansion of material, a shock
wave that measures approximately 600 lbs of
pressure per square inch moves outward from
the arc.
• Anyone in this blast area will be moved out of
the blast area, forcefully.
Cooper Bussman Studies
• Cooper Bussman and many other companies
have done extensive testing of arc blasts since
1997.
• The following slides demonstrate the power of
an arc blast in a standard piece of equipment.
Electrical Arc
35,000 °F
Molten Metal
Pressure Waves
Sound Waves
Copper Vapor:
Solid to Vapor
Expands by
67,000 times
Shrapnel
Hot Air-Rapid Expansion
Intense Light
Personnel Hazards Associated with Arc
Flash
Heat – Burns & Ignition of Materials
Arc
temperature of 35,000 ºF
Molten metal,
copper vapor, heated air
Second Degree Burn Threshold :
80 ºC / 175 ºF (0.1 sec), 2nd degree burn
Third Degree Burn Threshold:
96 ºC / 205 ºF (0.1 sec), 3rd degree burn
Intense Light
Damage eyes – cataracts
Personnel Hazards Associated with Arc Flash
Pressures From Expansion of Metals & Air
Eardrum Rupture Threshold
720 lbs/ft2
Lung Damage - Threshold
1728 - 2160 lbs/ft2
Shrapnel
Flung Across Room or From Ladder/Bucket
IEEE/PCIC & NFPA 70E
Arc Flash Hazard
Arc Flash Hazard
• Following are some of the tests run
by IEEE Ad Hoc Safety Committee
• All of the devices used for this testing
were applied according to their listed
ratings
Setup Area For Tests
• A standard electrical
room set up
• The test will be
performed on a
relatively low hazard
area.
– Not the switchgear
– 30A disconnect
Close-up of Test Area
Test Info
22.6 KA Symmetrical
Available Fault Current
@ 480V, 3 Phase
6 cycle STD
Set @ 6 cycle opening
640A OCPD
Non Current Limiting
with Short Time Delay
Fault Initiated on
Line Side of 30A
Fuse
30A RK-1
Current Limiting Fuse
Size 1 Starter
TEST
TEST Arc Blast Begins
TEST : Molten Copper
TEST: Copper vapor leads to a
second blast in gutter
TEST: Second blast fire ball
TEST: Metal, copper and PVC
continue to burn
TEST: Room enveloped in
toxic smoke
Results:
Test
22.6 KA Symmetrical
Available Fault Current
@ 480V, 3 Phase
Opened in
six cycles
No Current
Limitation
Fault Initiated on
Line Side of 30A
Fuse
640A OCPD
Non Current Limiting
with Short Time Delay
30A RK-1
Current Limiting Fuse
Size 1 Starter
Results: Test
Sound
141.5 db @ 2 ft.
P1
T2
>2160 lbs/sq.ft
> 225 C /437 F
T3
50 C / 122 F
T1
> 225 C /
437 F
> Indicates Meter Pegged
How Do We Protect Ourselves
• Use the STOP Principal
–Stop
–Think
–Options
–Protections
Lock Out/ Tag Out
• We will discuss methods of protecting you
from the hazards of electricity later in the
class.
• The best method of protection is to deenergize the circuit.
The ESP
• Now let’s review the Electrical Safety Policy
and How it will be used to help reduce the
effects of electrical hazards.
• The ESP is based on NFPA 70E. The Standard
for Electrical Safety in the Workplace.
NFPA 70E
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First published in 1997
Published by the NFPA
Updated in 2000, 2004 and 2009.
Now a part of the NEC code making process
and formatted in the same manner.
OSHA and NFPA 70E
• Six states have adopted NFPA 70E as the basis
for electrical safety.
• The Federal OSHA requirements are in the
process of being modified to meet NFPA 70E
standards.
• NFPA 70E can be used by OSHA compliance
officers now as a basis for a citation.
Overview of Safety Policy
• The policy can be broken into three parts
– Administration
– Hazard Prevention
– Hazard Control
Policy Requirements
• All employees are required to read the entire
policy and make themselves familiar with the
requirements of the policy.
• Ask your supervisor if you do not understand
any of this policy.
Policy Overview
• In this course we will cover some of the
requirements of the electrical safety policy.
Personal Protective Equipment
• Gloves
• Tools
• FR Clothing
– Double Layered
– All Cotton unclothing
• Eye protection
• Face protection
• Ear protection
Selection of Equipment
• All personal protective equipment shall be
selected based on the NFPA 70E charts
provided in the electrical safety policy.
• You can download this chart from the main
module page.
Authorization
• No energized work may take place until a
completed Energized Work Form has been
submitted and approved by the site
superintendent, the project manager, the
Director of Education and Loss Prevention and
either the Director of Service or the VP of
Operations.
• The Energized work form must be completed
in detail and completely.
Hazard Risk Analysis
• The most important part of protecting
ourselves is to identify the hazards and find
means to reduce and control those hazards.
• We accomplish this with the Hazard Risk
Analysis.
• A hazard risk analysis example is included in
the Electrical Safey Policy. Be sure to
download this from the module and read it.
Avoiding The Situation
• Ensure that power is locked out and tagged
• Ensure temporary power panels are locked so
that only E Light Personnel may operate
• Ensure that only qualified and authorized
personnel energize circuits
• Ensure that all terminations are completed in
a safe manner prior to energizing any circuits.
– Never Assume
Review of Policies
• We will discuss the Electrical Safety Policy and
the Safety Plan for Solaris Project Regarding
the Energizing of Electric Systems
• No work may occur or any circuit may be
energized unless all of the conditions and
procedures of the Safety Plan for Solaris
Project Regarding the Energizing of Electric
Systems have been successfully accomplished
“Do Not Tell Me It’s Dangerous.”
• Most electricians inform customers that it is
dangerous to work on live equipment and circuits.
• They already know this. That is why they call us.
• We have to show them the risks they are taking
when we work energized.
• We need to ensure our clients are satisfied with our
work but we are also the experts in the electrical
field. It is our responsibility to inform them of unsafe
conditions.
Our Responsibility
• We are the electrical experts
– We must say no when we are requested to do
something that is unsafe
– We must say no when we are asked to circumvent
the procedure or policy, even if it is just one time,
and even if it is “urgent or important.”
– The Weitz Company and Helix E Light have agreed
to implement this policy on the jobsite and both
companies have agreed to follow the procedures
to improve the electrical safety on the project.
The Risks of Not Following the
Procedures
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Injury or Fatality
Uncontrolled shutdown
OSHA Investigation
Replacement of parts
Downtime to make repairs
Monetary damages
Summary
• Electricity is the most powerful force
commonly used by mankind.
• We as electricians are exposed to it’s energy
more than anyone else.
• We must take every precaution to ensure our
safety and the safety of others.
• We want you to go home the same way you
came to work.
S.T.O.P.
When an electrician
makes a mistake, people
can die….
Including the
electrician!!!!
• Return to the module main page and
complete the test.
• Thank you,
• Ted Smith