Download Read the full document - Four Corners Safety Network

Moving Equipment Safely
around Power Lines
Presented by: Farmington Electric Utility
FCSN-Equipment Move Task Force
Equipment Move Task Force
&
Farmington Electric Utility
Presenter
Steve Henson System Operations Manager
Farmington Electric Utility
Objective
An electrical hazard can exist during any
number of situations or emergencies that oil field
workers are exposed to every day. This training
has been designed to assist area Companies
and other agencies in providing a safe work
atmosphere for their personnel in working
around electricity and accidental contact and
other electrical emergencies.
Agenda
 Common Myths
 The basic electric circuit
 Effects of electricity on the
human body
 Line Identification
 What to do if contact is
made
 Step Potential, How to get
away!!
 What can be done to make
equipment moves safer?
Fatal Electrical Workplace Accidents
2003-2007
Worker contact with electric current was responsible for 1,213 fatal workplace accidents from
2003-2007 and 13,150 workers were so severely injured from electrical contacts that their injuries
required time off from work. Data: Electrical Safety Foundation International (ESFI)
According to the Electrical Safety
Foundation International (ESFi)
• Power lines are the single greatest on the
job electrical hazard, killing an average of
133 workers per year.
• Our goal is to do our part in the Four
Corners to reduce this number by
educating our field personnel of the
hazards associated with electrical power
lines during equipment moves and working
on the job sites.
Common Myths about
Electricity
 The lowest line on a pole is safe to contact.
 Electricity will jump several feet to a person
or object.
 The tires on a vehicle will protect a person
from electricity.
 It is safe to use any insulating material to
contact an electric line. (Wood, fiberglass,
rope, PVC….)
 All overhead power lines are insulated to
protect against accidental contact.
Myth: The lowest line on a pole is
safe to contact.
The lowest line on a pole is not always
the safest line.
In the top picture, the low line is a
communications line, a low hazard
potential.
However, the lowest line in the bottom
picture shows the high voltage line as
the lowest line on the pole and has a
very high hazard potential. Utilities use
this type of construction for lightning
protection on the line.
Myth: Electricity will jump several
feet to a person or object.
This statement can be true depending on
the voltage.
You don’t need to contact a power line to
be in danger; electricity can jump, or arc,
from a power line to a worker who gets
too close. The best insulator is lots of
space. Workers should keep themselves
and any equipment they’re using a
minimum of ten feet away from power
lines, but far greater safe distances are
recommended when possible. Certain
conditions, such as smoke or dust can
increase the arcing distance
considerably.
Myth: The tires on a vehicle will
protect a person from electricity.
Tires offer little or no protection to
a driver or passenger who
attempts to exit a vehicle when
contact with high voltage is made.
Most tires have steel cores and
the rubber is contaminated from
being on the roads. High voltage
will track across the tires and go
to ground. A very high amount of
heat is created and in most cases
the tires will start on fire. Multiple
tires may be involved, we will
discuss parallel paths in a later
slide.
Myth: It is safe to use any insulating
material to contact an electric line.
(Wood, fiberglass, rope, PVC …)
There are many different types of
insulating materials. But only
those tools designed and tested
for electrical work can be used to
contact energized electric lines
and equipment. These specialized
tools also require proper training to use!
Untested materials, such as
wooden broom handles, 2x4’s,
rope and PVC pipe, can be
contaminated, wet or cracked
allowing voltage to pass through
the material.
Myth: All overhead power lines are
insulated to protect against
accidental contact.
While a few power lines
may have a covering to
protect against weather,
they are not insulated for
contact. Birds can sit on
power lines unhurt
because they don’t
represent a path to
ground. You, your trucks
and tools do.
The Basic Electrical System
The Basic Electrical Circuit
Voltage - The “pressure” that
pushes an electrical charge
through a conductor.
Amperage or Current - The
measure of electrical current
flow.
Resistance - The opposition
to electrical current flow,
measured in Ohms.
It’s your choice, the circuit can
look like this….
Or like this…….
One Amp of Electricity or Less can KILL
1 Milliamp =
1/1000 of an
amp
2 Milliamps –
Mild shock
10 milliamps –
Can’t let go
50 milliamps –
Breathing
difficult
100 milliamps –
Heart Stops
300 milliamps –
Severe Burns,
breathing stops
Ohm’s Law
For example…
•In your home, a 100 watt light bulb uses 120 volts and
has 144 ohms of resistance, this equals 833 milliamps
of current. 120 / 144 = .833 or 833 mA.
•If you contact a 120 volt source in your home, and
your body has 500 ohms of resistance, you will receive
240mA through your body. 120/500= .240 or 240 mA
High Voltage Electricity on the
Human Body
Each victim will have an entrance and an
exit wound on their body
The amount of damage to the body
depends on the current, time of exposure,
and the part of the body affected.
How much Electricity does it take to KILL?
Step Potential
Caution: A few of the following pictures are
graphic.
480 Volt Flash Burns
Exposure to between
4000 and 8000 volts.
Entrance
wound
Exit wound
Exposure to an excess of 7500
volts
Burns from Electrical contact
Contact with a high voltage line can
be devastating, damage to
equipment, or worse…..
Yes! Even Deadly……
Step Potential
High Voltage
Line
Path to ground
Step Potential Voltage Ring
If your vehicle or load comes in contact
with power lines:
•Attempt to drive away from the contact. If
your vehicle will not move…….
•Remain calm and stay in the vehicle.
•Instruct bystanders to stay away. If you
are able, call for emergency help or have
someone else call.
• If you must exit the vehicle due to fire or
other life threatening situations, due so
by standing at the edge of the vehicle
and jump away. Keep both feet together
and hop or shuffle away from the vehicle.
DO NOT touch the vehicle and the
ground at the same time!
How to move from a downed line.
Parallel Path
In simple terms, current will follow more than one path to ground.
If you touch a vehicle that is in contact with a high power line, and
you see arcing at one of the tires, you may still become a path to
ground. Electricity will find as many paths as is can to go to
ground, all can be fatal.
Another example of a Parallel
Path!
Contact with high voltage
Distribution Line
Driving under high voltage lines
So what do the regulations say?
OSHA Regulation states
1910.333(c)(3)(iii)
"Vehicular and mechanical equipment."
1910.333(c)(3)(iii)(A)
Any vehicle or mechanical equipment capable of having parts
of its structure elevated near energized overhead lines shall be
operated so that a clearance of 10 ft. (305 cm) is maintained. If
the voltage is higher than 50kV, the clearance shall be
increased 4 in. (10 cm) for every 10kV over that voltage.
However, under any of the following condition, the clearance
may be reduced:
1910.333(c)(3)(iii)(A)(1) If the vehicle is in transit with its
structure lowered, the clearance may be reduced to 4 ft. (122
cm). If the voltage is higher than 50kV, the clearance shall be
increased 4 in. (10 cm) for every 10 kV over that voltage.
Identifying types of power lines
Power lines come in many
different voltages and
configurations.
Knowing what you are dealing
with is very important.
You may not be able to identify
the exact voltage, but at least
know the class or type of line
you are working around.
Transmission
Distribution
Secondary (low voltage)
Communications
Electric lines can come in many
different shapes and sizes
Transmission
Distribution
Secondary
Communication
Transmission Lines
Voltages from 69,000
to 345,000 volts in
this area. (There are
still higher voltages in
other areas.)
345KV transmission lines
230KV transmission lines
115KV transmission line
69KV transmission line
Distribution Lines
Voltages range from
2400 volts to 8,000
volts phase to
ground and 4,160
volts to 14,400 volts
phase to phase.
3 Phase distribution line
3 Phase distribution line
3 Phase distribution line with
neutral on top.
3 Phase distribution line with
slim line construction
Single phase line
Single phase line with neutral
on top of pole.
Secondary Lines
Lower voltages, from
110 volts to 480 volts,
three phase and
single phase. (Low
voltage is generally
considered anywhere
from 1 to 600 volts)
Secondary line (120/240 volts)
Communication Lines
Communication lines connected to pole.
In most cases, communication lines are connected without an
insulator.
Multiple communication lines.
This pole has fiber lines and copper communications lines.
So, what can we do to make
equipment moves safer?
Train all employees about the hazards.
Take the time to plan the job!
Consider all overhead lines as energized.
Conduct a route survey before moving and
survey for overhead lines that cannot be
cleared.
Contact the utility company for proper ID
of lines and assistance with having the
lines moved or de-energized.
Ensure that workers keep at least 10 feet
away from all overhead lines and never use
any conductive or un-tested material to
touch a line. Only qualified persons trained
in accordance with OSHA 1910.269 are
allowed to touch lines with any device.
While equipment is in transit, maintain at
least 4 foot of clearance from overhead
lines. If you can’t maintain that clearance,
STOP THE JOB and re-evaluate before
proceeding.
Moving Equipment Safely
Around Power Lines
What action will
YOU
take to help minimize the
hazard?
The End
Questions ???
Contact Steve Henson, Farmington Electric Utility
E-mail: [email protected]
Phone: 505-599-8331