ELECTRICAL SAFETY
RELATED WORK PRACTICES
FOR GENERAL INDUSTRY
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ELECTRICAL HAZARDS
What is an electrical hazard?
 Electricity and the Human Body
 Electrocution
 Arc Blasts & Pressure Waves
 Secondary Effects

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Types of Electrical Hazards
Electrocution
 Arcs & Blasts
 Secondary Hazards (fire, falls)

An electrical hazard is any potential threat to health and or property
caused by inadvertent contact with, or release of, electricial energy.
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Electrical Shocks
Resistance of human body varies
widely; 10,000 ohms is “typical”.
 5mA of sustained current is usually
considered the threshold value of
physiological damage .
 Threshold voltage=10,000 ohms x .005
amps or 50 volts.

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Electricity and the Human Body
At 5 mA pain begins.
 At 10 mA paralysis of limbs (arms)
occurs.
 At 30 mA breathing stops.
 At 75 mA fibrillation occurs.
 Above 250 mA fibrillation ceases.
 At 4 amps breathing ceases.
 At 5 amps tissue burns.

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Arc Blasts & Pressure Waves
Injuries & deaths due to arc burns are
roughly one fourth of electrical hazard
related casualties.
 Radiation burns can kill up to 5 ft
 Arc temperatures up to 30,000 degrees
Pressure waves created by arc blasts
have been known to knock walls down
at 30 ft!

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Electricity is the “perfect” hazard: it can’t be
seen, smelled or heard!
The grim statistics from the Natonal Safety Council:
Between 500-600 people in the U.S. die by
electrocution or arc blast yearly.
350-400 workers die by electrical current yearly.
Electrical accidents are the 8th leading cause of
death in the workplace.
All electrocutions are preventable!
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THE 4 LINES OF DEFENSE
TRAINING FOR ALL AFFECTED PERSONNEL
PROPER EQUIPMENT
SELECTION OF PROPER WORK PRACTICES
PLANNING AND PROCEDURES
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APPLICATION OF OSHA
SRWP IN THE WORKPLACE
Who Needs Training?
 What Kind of Training?
 Work Practices
 Proper Selection & Use of Equipment
 Are Written Procedures Necessary?

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WHO NEEDS TRAINING?
Anyone who works on or near enough
to exposed live parts or parts which
might become energized (potential
hazard) must receive training.
 Examples : Electricians, construction
crews on industrial sites, heavy
equipment operators, machine
operators, janitors-in short, potentialy
anyone at your facility!

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WHAT KIND OF TRAINING?
Training requirements depend on the
extent of potential exposure.
 Training may be OJT or classroom or
both.
 Extent of training depends on whether
person is qualified or unqualified.

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Qualified vs Unqualified
DEFINITION : A qualified person (OSHA
definition) is “one who is familiar with
the construction and operation of the
equipment and the hazards involved.”
 This definition applies to specific
equipment.

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TRAINING
Training required for both qualified and
non qualified personnel working on or
near parts which are energized or might
be energized.
 Qualified personnel must be trained in
work practices, determine nominal
working voltage, know line clearances.
 Unqualified personnel working in
vicinity must be trained to extent
necessary.

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Training for Qualified
Personnel
Must be able to identify energized parts.
 Ability to determine nominal workimg
voltages.
 Must know applicable clearances vs
voltages IAW 1910.333(c).
 Trained in SRWP as applied to job.

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Training for Unqualified
Personnel
Unqualified trained to the extent
necessary.
 EXAMPLE: Housekeeping crews should
be shown safe cleaning distances from
equipment with live circuits and
instructed in the use of nonconductive
cleaning techniques in potentally
conductive locations.

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Training for Unqualified
Personnel (Con’t)
EXAMPLE: Machine operators trained
in their role in LOTO.
 EXAMPLE: Fork lift operators instructed
by memo and verbally to avoid certain
overhead line locations in your plant.
 EXAMPLE: Manufacturing personnel
instructed by supervisor to avoid
barricaded areas.

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Occupations Requiring Training
Blue collar supervisors
 Elec/electronic engineers, techs,
assemblers
 Electricians and welders
 Industrial machine operators
 mechanics,repairers, painters, riggers,
roustabouts,stationary engineers

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Selection and Use of Safety
Related Work Practices
Parts must be deenergized before work
except as noted in 1910.333(a)(2) and
less than 50 volts. 1910.333(a)(1)
 Work can be performed on energized
parts in case of infeasibility or increased
hazard of deenergized parts.
1910.333(a)(2)
 Deenergized parts must be treated as
energized or locked out. 1910.333(b)(1)

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Lockout/Tagout (LOTO)
LOTO subject to OSHA review.
1910.333(b)(2)(i)
 Procedures must be in place before
deenergizing circuits. 1910.333(b)(2)(ii)
 Rules governing use of locks and tags.
1910.333(b)(2)(iii)
 Verification of deenergization required.
1910.333(b)(2)(iv)
 Restart procedures. 1910.333(b)(2)(v)
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
Safety Related Work Practices
for Exposed Energized Parts
Only qualified personnel may work on
energized equipment. 1910.333(c)(2)
 Overhead lines. Deenergize or
protective measures. Minimum
approach distances. 1910.333(c)(3)

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LIVE PARTS
3 ft for 0-150 volts
3 ft for 151-600 volts
INSULATED PARTS
OR WALL
Condition a
LIVE PARTS
LIVE PARTS
3 ft for 0-150 volts
3.5 ft for 151-600 volts
Condition b
3 ft for 0-150 vollts
3.5 ft for 151-600 volts
Condition c
GROUNDED
PARTS
LIVE PARTS
WORKING CLEARANCES, LIVE PARTS, 0-600 VOLTS
From Table S-1, 29 CFR 1910
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APPROACH DISTANCES TO LIVE PARTS
Flash
Limited
Protection Space
Required
Flash
Protection
Boundry
A
Restricted Prohibited
Space
Space
Exposed Live
Part, Fixed
B
C
A.Qualified personnel only
B. Qualified personnel, approved plan, PPE.
C. All requirements in B plus specific training & risk assesment.
Adapted from NFPA 70E, Ch. 2-21
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APPROACH DISTANCES TO LIVE PARTS, 300 V & LESS
Flash
Limited
Protection Space
Required
Flash
Protection
Boundry
A
Restricted Prohibited
Space
Space
Exposed Live
Part, Fixed
B
C
A.Qualified personnel only
B. Qualified personnel, approved plan, PPE.
C. All requirements in B plus specific training & risk assesment.
Distances from live part to outer boundries
Flash protection: 3 feet
Limited space: 3 1/2 feet
Prohibited space avoid contact
S- 23Restricted space avoid contact
APPROACH DISTANCES TO LIVE PARTS, 751 to 2,000V
Flash
Limited
Protection Space
Required
Flash
Protection
Boundry
A
Restricted Prohibited
Space
Space
Exposed Live
Part, Fixed
B
C
A.Qualified personnel only
B. Qualified personnel, approved plan, PPE.
C. All requirements in B plus specific training & risk assesment.
Distances from live part to outer boundries
Flash protection: 4 feet
Limited space: 4 feet
Prohibited space: 3 inches
S- 24Restricted space: 2 feet
Work Practices (Con’t)
Procedures required for handling all
conductive materials. 1910.333(c)(6)
 Nonconductive ladders. 1910.333(c)(7)
 Conductive apparel must be insulated.
1910.333(c)(8)
 Adequate Illumination required.
1910.333(c)(4) and ANSI 11.1

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Work Practices (Con’t)
Safeguards required for housekeeping
duties. 1910.333(c)(9)
 Interlocks: only qualified personnel may
defeat and only on a temporary basis.
1910.333(c)(10)
 Alerting techniques required in exposed
hazardous locations. 1910.335(b)

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Electric Power & Lighting
Live load disconnects must be load
rated. Breakers not marked “SWD”
cannot be used to make\break live
loads!
 Breakers operated under fault
conditions must be replaced. Breakers
operated under overload should be
examined.
 It is unlawful to degrade overload
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
ungrounded cord
2 wire cord with pigtail
COMMON CORD AND PLUG VIOLATIONS
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WORKING ON OR NEAR EXPOSED LIVE PARTS REQUIRES PERSONAL
PROTECTIVE EQUIPMENT:29 CFR 1910.333(c)(2). EXPOSED
BODY PARTS MUST BE PROTECTED: 29 CFR 1910.335(a)(1).
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Portable Electrical Equipment
HANDLING: Tools shall not be handled
by connecting cords or unsafely.
 VISUAL INSPECTION FOR DAMAGE.
 Must have grounding conductor or be
double insulated or be battery operated.
 Tools used in damp or wet locations
must be rated for use in those
environments.
 Attachment plugs cannot be altered!
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
TEST EQUIPMENT
Only qualified personnel are permitted
to use test equipment on live circuits.
 Test equipment must be used within
ratings.

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Safeguards for Personnel
Protection
Protective equipment is required in
hazardous locations. 1910.335(a)(1)
 General Equipment & Tools. Insulated
tools required when working near
exposed live parts. Includes fuze
pullers/installers,ropes, shields,etc.
1910.335(a)(2)

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Are Written Procedures
Necessary?
Written procedures increase training
effeciency, protect employer and
employee.
 Written procedures are required for
Lockout/Tagout.
 Procedures required for both enclosed
and confined work spaces.
1910.335(c)(5)

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Acnowledgements
Ralph H. Lee Electricity and the Human Body,
IEEE Transactions
Accident Facts, National Safety Council, 1996 ed.
Jack McDaniel Work Book for Electrical Safety
Related Work Practices and Lockout/Tagout
for General Industry
James G. and James W. Stallcup Electrical
Regulations Simplified
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