Subcontractor Electrical Safety

1
Subcontractor Electrical Safety NFPA 70E

• Electrical Safety for Subcontractors and
  Subcontract Technical Representatives
• EFCOG Electrical Safety Task Group
• Module 8

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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)
• 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
• 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
The closest distance an unqualified person can
approach, unless escorted by a qualified person.
Energized panel (lt750V)
3 feet 6 inches for 480V
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Limits of Approach Restricted Approach Boundary
Prohibited
Restricted
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.
Energized part
12 inches for 480 volts
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Limits of Approach - Shock
Prohibited
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.
Energized part
1 inch for 480 volts
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Approach Boundaries for Shock Protection
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Limits of Approach 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.
• Note Distance may be less than or greater than
  the shock protection boundaries.

Flash Protection Boundary
Prohibited
Restricted
Limited
Energized part
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

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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.
• 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 lt 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 every 6
  months.

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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

• Dont 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?
• 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
• 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