Transcript subcontractor electrical safety nfpa 70e

Subcontractor Electrical Safety & NFPA 70E
Electrical Safety for Subcontractors and
Subcontract Technical Representatives
EFCOG Electrical Safety Task Group
Module 8
Objective
 To provide understanding of electrical safety
requirements for the Subcontract Technical
Representative and the Subcontractor
 To facilitate communications of requirements to the
subcontractor
 To serve as an aid in assessing a subcontractors
performance
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NFPA 70E, Standard for Electrical Safety in the Workplace
 Why is NFPA 70E a subcontractor requirement?
– DOE Order 440.1A, Worker Protection Management For DOE And Contractor
Employees Requires Implementation
– OSHA General Duty Clause requires “workplace free from recognized hazards”.
OSHA has cited General Duty Clause for failure to comply with 70E
– 10CFR 851 requires compliance with NFPA 70E
– NFPA 70E, Section 110.4 Multiemployer Relationship
• (A) Safe Work Practices. On multiemployer worksites (in all industry
sectors), more than one employer may be responsible for hazardous
conditions that violate safe work practices.
• (B) Outside Personnel (Contractors, etc.)… the on-site employer and the
outside employer(s) shall inform each other of existing hazards, personal
protective equipment/clothing requirements, safe work practice
procedures… applicable to the work to be performed.
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Can OSHA Cite NFPA 70E?
 OSHA regulations are often described as the “Shall” and NFPA
70E as the “How” for electrical safety in the workplace.
 OSHA commonly cites the General Duty Clause and uses NFPA
70E as evidence of compliance
 From an OSHA Letter of Interpretation dated July 23, 2003:
“Industry consensus standards, such as NFPA 70E, can be used
by employers as guides to making the assessments and
equipment selections required by the standard. Similarly, in
OSHA enforcement actions, they can be used as evidence of
whether the employer acted reasonably.”
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NFPA 70E, Standard for Electrical Safety in the Workplace
 How does NFPA 70E differ from the National Electric
Code (NEC)?
– NFPA 70E is intended to provide work practices to minimize
the worker from electrical energy when using or working on
or near electrical equipment and conductors
– The NEC is intended to provide a safe electrical installation
so that equipment is safe when operating normally
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NFPA 70E, Standard for Electrical Safety in the Workplace
 What work practices does NFPA 70E require?
– Chapter 1, Safety-Related Work Practices
• Article 100, Definitions
• Article 110, General Requirements for electrical Safety-Related
Work Practices
• Article 120, Establishing an Electrically Safe Work Condition
• Article 130, Working On or Near Live Parts
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NFPA 70E Training Requirements
Employees shall be trained to understand specific
hazards associated with electrical energy
– Trained in safety related work practices and procedural
requirements for specific job or task
– Trained to understand relationship between electrical
hazards and possible injury
– Training shall be classroom or on-the-job type or
combination
– Employees working on or near energized conductors shall
be trained in release of victims from contact
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NFPA 70E Qualified Person
A qualified person shall be trained and knowledgeable of
construction and operation of equipment or work
method and trained to recognize and avoid hazard
(110.6(D)(1))
– Familiar with precautionary techniques, personal protective
equipment including arc flash, insulating and shielding
materials, insulated tools and test equipment
– Distinguish exposed energized parts from other parts
– Determine nominal voltage of live parts
– Understand safe approach distances in Table 130.2C
– Determine personal protective equipment for task
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NFPA 70E Job Briefing
Before starting each job, employee in charge shall
conduct a job briefing with employees involved.
(110.7G)
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Identify hazards
Identify procedures to be followed
Special precautions
Energy source controls
Personal protective equipment
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Electrical Safe Work Condition
Live parts to which an employee might be exposed shall
be put into an electrically safe work condition before an
employee works on of near them unless the employee
can demonstrate work on energized components can
be justified (110.8A)
– Deenergizing introduces additional or increased hazards
(Examples include interruption of life support equipment,
deactivation of emergency alarm systems, shutdown of
hazardous location ventilation equipment)
– Deenergizing is infeasible due to equipment design or
operational limitations. (Examples include start-up or
troubleshooting diagnostics and testing)
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Electrically Safe Work Condition
 Infeasible
– adj : not capable of being carried out or put into practice
 Inconvenient
– adj : not suited to your comfort, purpose or needs
 “Financial considerations are not an adequate reason
to work on or near energized circuits” (Std. 1584-2002
IEEE)
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Achieving an Electrically Safe Work Condition
An Electrically Safe Condition shall be achieved by completing all
the following
 Determine all sources of electrical supply (Drawings, diagrams)
 Open disconnecting device for each source
 Visually verify all blades of disconnecting devices are fully open
or drawout-type breakers are withdrawn
 Apply lockout/tagout devices in accordance with policy
 Test each phase conductor using adequately rated voltage
detector
 Ground phase conductors where possibility exists for induced
or stored energy
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Achieving an Electrically Safe Work Condition
Electrical conductors and circuit parts that have been
disconnected but not under lockout/tagout, tested and
grounded (where appropriate) shall not be considered
to be in an electrically safe work condition
– Safe work practices shall be used in this case identical to
working on or near exposed live parts
– Applies regardless of whether equipment is temporary,
permanent or portable
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Energized Electrical Work
If live parts are not placed in an electrically safe work
condition, work shall be considered energized
electrical work
– A written Energized Electrical Work Permit shall be required
where live parts are not placed in an electrically safe work
condition.
– Exemption: work such as testing, troubleshooting, voltage
measurement shall be permitted to be performed without an
energized electrical work permit provided appropriate safe
work practices and PPE are provided and used.
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Elements of Energized Electrical Work Permit
 Permit shall include the following items
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Description of circuit and equipment to be worked
Justification for performing work in energized condition
Description of safe work practices
Results of shock hazard and flash hazard analysis
Shock protection boundary
Personal protective equipment
Means to restrict access to unqualified persons
Evidence of job briefing
Work approval signatures
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Working on or Near Exposed Electrical
Conductors or Circuit Parts
Perform electrical hazard analysis if live parts (50 volts or
more) can not be placed in an electrically safe work
condition
 Shock Hazard Analysis (Determine limited, restricted
and prohibited approach boundaries and shock PPE)
 Flash Hazard Analysis (Determine arc flash boundary
and PPE for personnel within this boundary)
 Use Energized Electrical Work Permit
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Shock and Arc Boundaries
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Limits of Approach – Limited Approach
Boundary
Prohibited
Restricted
Limited
Energized
panel
(301V to
750V)
3 feet 6 inches for 480V
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The closest
distance an
“unqualified”
person can
approach, unless
escorted by a
“qualified” person.
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Limits of Approach – Restricted Approach
Boundary
Prohibited
Energized
part
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Restricted
12 inches for
480 volts
The closest distance to
exposed live parts a
“qualified” person can
approach w/out proper
PPE and tools.
To cross this boundary,
the qualified person
must wear PPE and
have proper tools.
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Limits of Approach - Shock
Prohibited
Energized
part
1 inch for
480 volts
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Crossed ONLY by a “qualified”
person, which when crossed by
body part or object, requires the
same protection as if direct
contact was made with the live
part.
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Approach Boundaries for Shock Protection
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Limits of Approach – Flash Protection
Boundary
Prohibited Restricted
Limited
Flash
Protection
Boundary
•The distance from exposed
live parts within which a
person could receive a
second degree burn if an
arc flash were to occur.
•Arc flash PPE is required
within this boundary.
Energized
part
•Note: Distance may be
less than or greater than
the shock protection
boundaries.
Calculated distance
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Flash Hazard Analysis
 An arc flash hazard analysis shall be done to protect
personnel from injury by arc flash exposure
 This analysis determines the flash protection boundary
and potential thermal exposure to personnel working
on or near exposure live parts within the boundary
 Personal protective clothing and protective equipment
for workers inside the flash protection boundary are
then selected to mitigate potential thermal exposure
 Equipment may be labeled with the results of the arc
flash hazard analysis and shock protection analysis
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Typical Equipment Label
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Personal Protective Clothing
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Examples of PPE
Hazard Risk
Category 0
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Hazard Risk
Category 1
Hazard Risk
Category 2
Hazard Risk
Category 3
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Hazard Risk
Category 4
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Alternative to Flash Hazard Analysis
 The PPE requirements of NFPA 70E, 130.7(C)(9)(a) shall
be permitted in lieu of the detailed flash hazard
analysis
– Use Table 130.7(C)(9)(a) to determine hazard/risk category for
task
– Ensure the short circuit capacities and fault clearing time for
task listed in the text and notes are not exceeded
– Use Table 130.7(C)(10) to determine the PPE for the task
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Table 130.7(C)(9)(A)
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Table 130.7(C)(10)
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Example Using Alternative Method
Work task involves testing for absence of voltage inside a
480 volt MCC cubicle to establish a lockout point.
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What is the Hazard/Risk Category?
What notes apply to the task?
Are V-rated glove and tools required?
What PPE is required for the Qualified Worker?
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Example Using Alternative Method
Answer
 Refer to “600 V Class Motor Control Centers” section in Table
130.7(C)(9)(A) and choose task for “work on energized parts,
including voltage testing. Hazard/Risk Category is 2*
 Notes 2 and 3 apply to this task. Confirm with Engineering that
short circuit current of 65kA and 0.03 fault clearing time not
exceeded. If short circuit current < 10 kA, hazard/risk category
can be reduced by one number
 V-rated gloves and tools are required
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Example Using Alternative Method
Using Table 130.7(C)(10), identify PPE requirement listed
under Category 2
T-shirt
Long sleeve FR shirt and pants or coveralls
Hard hat
Safety glasses or safety goggles
Flash suit hood and hearing protection (2* footnote to Table
130.7(C)(9)(A) requires hood for this task)
– Leather gloves over voltage rated gloves
– Leather work shoes
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Personal Protective Equipment Care
 Clothing shall be inspected prior to use by user.
– Clothing or flash suits that are damaged shall not be used.
– Clothing that become contaminated with grease, oil or flammable liquids
or combustible materials shall not be used.
 V-rated gloves shall be inspected prior to use by user. Shall be
tested and certified before first use and every 6 months
thereafter.
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Inspecting Voltage Rated Gloves in Field
•Visual Inspection
•Inflation
•Reverse glove and repeat
•Store in appropriate glove bag
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Precautions Working on or Near Live Parts
 Don’t reach blindly into areas that might contain
exposed live parts
 Provide illumination in spaces to enable safe work
 Conductive articles of jewelry and clothing such as
watchbands, bracelets, necklaces shall not be worn
 Use only insulated tools rated for voltage when
working inside the Limited Approach Boundary of
exposed live parts where contact might be made
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Typical Voltage Rated Insulated Tools
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Alerting and Barricades
 How to protect the shock and arc flash approach
boundaries from an unqualified person?
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Barrier tape
Orange cones
Signage
Plastic chain
Use an attendant to warn others approaching the area
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NFPA 70E Compliance for Subcontractors
 Summary
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NFPA 70E is more than just “Arc Flash” requirements
Elements provided, but entire standard may be applicable
Chapter 1 provides Safety-Related Work Practices
Subcontractor responsible for own personnel safety
Communication both ways is imperative
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