High Voltage Lines Training Guides
(Taken from the "Tailgate Meetings that Work : A Guide
to Effective Construction Safety Training" series) |
|
Robin Baker, Robert
Downey, Mary Ruth Gross, Charles Reiter
Labor Occupational Health Program
(LOHP) School of Public Health,
University of California, Berkeley Ca.
These tailgate/toolbox
talks were developed for use under California OSHA regulations. The
complete set is available from the Labor Occupational Health Program
at UC Berkeley. For ordering information, visit the website (www.lohp.org)
The American Conference of Government Industrial Hygienists (ACGIH)
has adapted these talks to apply to federal OSHA regulations. To contact
ACGIH, visit its web site (www.acgih.org). |
Before you begin
the meeting...
- Does this topic
relate to the work the crew is doing? If not, choose another topic.
- Did you read
this Training Guide and fill in the blanks where the
appears? (To find the information you need, look over the Safety Walkaround
Checklist for this topic.)
Begin: Electricity
jumps! Always keep yourself and your equipment a safe distance from high
voltage lines. Even low voltage can injure or kill you, but today well
be talking about high voltage. About 700 U.S. workers are killed by electricity
each year, many because they got too close to a high voltage line. Well
explain some steps to take if someone gets an electric shockbut
even the best emergency care cant always save a life. Its
best not to get too close to electricity in the first place.
You or a crew member may want to add a personal story about high voltage
electricity.
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Next, discuss
with the crew where there may be danger from high voltage lines
at this particular job site:
__________________________________________________
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ASK
THE CREW THESE QUESTIONS:
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After each question,
give the crew time to suggest possible answers. Use the information following
each question to add points that no one mentions.
1. Electricity
can be dangerous at any voltage, but our subject today is high voltage.
Does anyone know what we mean by high voltage electricity?
2. How far away
should you stay from an overhead high voltage line?
- People should
stay between 6 and 20 feet away, depending on the voltage. The higher
the voltage, the farther electricity can jump. No part of your body
should come within this minimum clearance distance.
- Most tools, equipment,
and machinery should also stay between 6 and 20 feet away.
- Lifting and hoisting
machinery (like cranes) should stay between 10 and 42 feet away from
the line, depending on the voltage.
- An electric line
might move (due to strain on the supporting structures, etc.) Your clearance
distance must also allow for this possible movement.
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Use
the Safety Walkaround Checklist for this topic to fill in the following
chart. If voltages and minimum clearances are different on different
parts of the site, list them separately for each area. Explain the
chart to the crew. |
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Line
Voltage
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Clearance
for People and Most Equipment
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Clearance
for Lifting and Hoisting Machinery
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3. What if you
have to work within the minimum clearance distance?
- Make sure the
electric line is de-energized.
- Consider any
line to be live unless you know it is de-energized and it
is visibly grounded.
4. Keep all
tools and equipment away from high voltage lines. You can get a serious
shock if anything youre using or carrying accidentally contacts
a line. What are some tools and equipment that you should be especially
careful with?
Metal ladders
Long pipes
Tree trimming
equipment
Cranes
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Scaffolds
Antennas
Extension
rollers used in painting
Lifting equipment
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5. According to
Cal/OSHA, there should be two signs on all cranes, derricks, power shovels,
pile drivers, and similar machinery, warning about the clearance distance
from high voltage lines. What information is on these signs?
- They say that
operators should keep this equipment at least 10 feet from high
voltage lines that carry 50,000 volts or less. The clearance distance
is more if the line carries higher voltage. These signs are requiredlet
your supervisor know if theyre not there.
6. If your electrical
resistance is low when you get a shock, more electricity will flow through
your body. That will usually cause more injury. What are some things that
can lower your resistance?
- Working in a
wet or damp location
- Using wet tools
- Sweating
- Working in contact
with good conductors like metal pipes, tanks, or boilers.
7. What kinds
of injuries can you get from a high voltage electric shock?
- High voltage
can stop your heart or your breathing.
- It can also cause
fibrillationa fast, irregular heartbeat.
- You can get a
serious burnexternal or internal.
- You can fall
off a ladder or scaffold and get injured.
- Even if youre
not on a ladder or scaffold, high voltage can throw youcausing
fractures or broken bones.
8. What should
you do if someone gets an electric shock?
- Dont touch
the person until power has been disconnected.
- Call 911.
- Calm and reassure
the injured person. Dont move them until trained help arrives.
- Notify the first
aid provider, clinic, or supervisor as soon as possible.
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Name of on-site
first aid provider or designated local clinic:
_________________________________________________
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Explain:
Most of the safety measures weve talked about are required by Cal/OSHA.
We have to take these precautionsits the law. I have a Checklist
of the Cal/OSHA regulations on high voltage electricity. If youd
like to know more, see me after the meeting.
(Only if applicable.)
Besides the Cal/OSHA regulations, we have some additional company rules
about high voltage electricity.
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Discuss company
rules:_______________________________
_________________________________________________
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Ask:
Do you have any other concerns about high voltage electricity? Do you
see any problems on our job? (Let the steward answer first, if there
is one.)
What about other jobs youve worked on? Have you had any experience
with high voltage electricity that might help us work safer on this job?
Date Prepared:_________________________ |
By:_______________________ |
Project
Name/No.______________________ |
Location:___________________ |
NAMES
OF THOSE WHO ATTENDED THIS SAFETY MEETING
|
Laborer Electrocuted by
Energized Crane
A 26-year-old construction
laborer was electrocuted when he tripped and came into contact with a crane.
The crane had become energized through accidental contact with a high voltage
line overhead.
The crane was in an area with both telephone and high voltage lines, and
the crane operator was aware of them. Earlier in the day, the crane had
brushed against telephone lines and had to be repositioned. However, at
this time in the late afternoon, the operator's vision of the high voltage
lines was obstructed because of the sun's position. The auxiliary line of
the crane made contact with the high voltage line. The auxiliary line burned
in two and the ball/hook assembly fell to the ground. Voltage was 16,000
volts.
The laborer was carrying a wire rope over to be used to attach a pile of
plywood to the crane's hook. The crane operator and laborer were both startled
by the fall of the ball/hook assembly. The boom of the crane momentarily
drifted, contacting the high voltage line directly.
The laborer was carrying a wire rope over to be used to attach a pile of
plywood to the crane's hook. The crane operator and laborer were both startled
by the fall of the ball/hook assembly. The boom of the crane momentarily
drifted, contacting the high voltage line directly.
May 12,
1992
What should have been
done to prevent this accident?
Preventive Measures
Cal/OSHA investigated
this accident and made the following recommendations.
Employers should:
- Provide information
to workers on what kinds of hazards to look for and how to avoid them.
- Develop and implement
strict safety procedures when working with a crane in the vicinity of
high voltage power lines.
- Contact the local
electric power company and have the power turned off when working within
a certain distance of high voltage power lines.
Tailgate Meetings That Work : Collection
Published in June, 1994 by: Labor Occupational Health Program, School of
Public Health, 2515 Channing Way, University of California, Berkeley, CA
94720. Phone: (510) 642-5507.
Permission is granted to duplicate these materials for non-profit educational
purposes, provided that copies are not offered for sale.
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