NFPA 70E Energized Work and Risk
Assessment & Mitigating Risks & PPE
Requirements & Safety Related
Maintenance and Special Equipment
Performing Energized Work - Answer: -Infeasibility, troubleshooting equipment malfunctions, taking
voltage measurements, de-energizing poses additional hazard, equipment is in normal operating
condition, equipment operates at a voltage under 50 volts
Energized Electrical Work Permits - Answer: -Energized electrical work permits must be completed any
time an employee will perform work within the restricted approach boundary.
- Who is requesting the work?, who is performing the work?, who is authorizing the work?
When is a Permit Not Required - Answer: -Tasks that pose little risk, tasks that are justified
-A qualified person using safe work practices and PPE is required for any justified energized work
Shock Risk Assessment - Answer: -Identify shock hazards,
-Estimate likelihood of occurrence of injury or damage to health
-Potential severity of injury or damage to health, determine if additional protective measures are
required
Approach Boundaries for Shock Protection - Answer: -Limited approach boundary is a distance at which
a shock hazard exists.
-Restricted approach boundary is a distance at which there is an increased likelihood of electric shock.
Limited Approach Boundary - Answer: -No qualified persons may cross the limited approach boundary
-Exceptions: permit unqualified to cross the limited approach boundary
-Limited Approach Boundary Table:
130.4(E)(a)
, Restricted Approach Boundary - Answer: -The employee is insulated or guarded from the energized
circuit parts
-Energized conductors or parts are insulated from the person and other conductive objects at a different
potential
Arc Flash Risk Assessment - Answer: -Identify if an arc flash hazard exists, estimate the level of risk the
employee, determine if additional protective measures are required
Arc Flash Variables - Answer: -Lack of maintenance, larger and smaller amounts of available fault current
, larger amounts of available fault current
Arc energy inside an enclosure can create extreme pressures. Proven equipment designs and practices
that may be used include:
-Arc resistant switch gear, remote racking, high resistance grounding
Arc Flash Boundary & Requirements - Answer: 1. Incident energy analysis = 1.2 calories / cm^2
-Table 130.5(G)
2. Arc Flash PPE Category
-The available fault current, the clearing time of the overcurrent protective device that will clear the
fault in the event one occurs.
Over Variables:
-System voltage, arcing time, distance from act to person, available bolted-fault current, arcing current
Arcing Flash and Arc Blast - Answer: Arcing Fault:
-Ionizes the air around energized circuit parts so air itself becomes a conductor, results in a lower level
of current flowing, could increase the clearing time of the OCPD
Bolted Fault:
Assessment & Mitigating Risks & PPE
Requirements & Safety Related
Maintenance and Special Equipment
Performing Energized Work - Answer: -Infeasibility, troubleshooting equipment malfunctions, taking
voltage measurements, de-energizing poses additional hazard, equipment is in normal operating
condition, equipment operates at a voltage under 50 volts
Energized Electrical Work Permits - Answer: -Energized electrical work permits must be completed any
time an employee will perform work within the restricted approach boundary.
- Who is requesting the work?, who is performing the work?, who is authorizing the work?
When is a Permit Not Required - Answer: -Tasks that pose little risk, tasks that are justified
-A qualified person using safe work practices and PPE is required for any justified energized work
Shock Risk Assessment - Answer: -Identify shock hazards,
-Estimate likelihood of occurrence of injury or damage to health
-Potential severity of injury or damage to health, determine if additional protective measures are
required
Approach Boundaries for Shock Protection - Answer: -Limited approach boundary is a distance at which
a shock hazard exists.
-Restricted approach boundary is a distance at which there is an increased likelihood of electric shock.
Limited Approach Boundary - Answer: -No qualified persons may cross the limited approach boundary
-Exceptions: permit unqualified to cross the limited approach boundary
-Limited Approach Boundary Table:
130.4(E)(a)
, Restricted Approach Boundary - Answer: -The employee is insulated or guarded from the energized
circuit parts
-Energized conductors or parts are insulated from the person and other conductive objects at a different
potential
Arc Flash Risk Assessment - Answer: -Identify if an arc flash hazard exists, estimate the level of risk the
employee, determine if additional protective measures are required
Arc Flash Variables - Answer: -Lack of maintenance, larger and smaller amounts of available fault current
, larger amounts of available fault current
Arc energy inside an enclosure can create extreme pressures. Proven equipment designs and practices
that may be used include:
-Arc resistant switch gear, remote racking, high resistance grounding
Arc Flash Boundary & Requirements - Answer: 1. Incident energy analysis = 1.2 calories / cm^2
-Table 130.5(G)
2. Arc Flash PPE Category
-The available fault current, the clearing time of the overcurrent protective device that will clear the
fault in the event one occurs.
Over Variables:
-System voltage, arcing time, distance from act to person, available bolted-fault current, arcing current
Arcing Flash and Arc Blast - Answer: Arcing Fault:
-Ionizes the air around energized circuit parts so air itself becomes a conductor, results in a lower level
of current flowing, could increase the clearing time of the OCPD
Bolted Fault:
