NFPA 70E COMPLIANCE GUIDE
This guide shall only be used in conjunction with performing the necessary calculations in a flash hazard analysis to determine the proper cal/cm 2. If the results of the calculations exceed the cal/cm2 that correspond to the HRC
found on this guide, you must use clothing that complies with the calculation.
Panelboards or Other Equipment Rated 240V and Below
- Note 1
Arc Flash Boundary = 19 in.
Task (equipment is energized & work is done
within the flash protection boundary)
Perform infrared thermography and other noncontact inspection outside the restricted approach
boundary
V-Rated
Gloves
V-Rated
Tools
600V Class Switchgear (with power circuit breakers or fused
switches) and 600V Class Switchboards - Note 4
Arc Flash Boundary = 233 in. (19' 5")
HRC
Task (equipment is energized & work is done
within the flash protection boundary)
V-Rated
Gloves
V-Rated
Tools
Metal Clad Switchgear, 1 kV thru 38 kV - Note 5
Arc Flash Boundary = 422 in. (35' 2")
HRC
0
CB or fused switch or starter operation with
enclosure doors closed
0
Circuit Breaker (CB) or fused switch operation with
covers on
0
0
CB or fused switch operation with
covers off
0
Reading a panel meter while operating a meter
switch
Work on control circuits with energized electrical
conductors and circuit parts 120 V or below,
exposed
Open hinged covers (to exposed bare, energized
electrical conductors and circuit parts)
0
Work on energized electrical conductors and circuit
parts, including voltage testing
Remove/install CBs or fused switches
Y
Y
1
Y
Y
1
Y
Y
0
Task (equipment is energized & work is done
within the flash protection boundary)
V-Rated
Gloves
V-Rated
Tools
Reading a panel meter while operating a meter
switch
CB operation with enclosure doors closed
Work on control circuits with energized electrical
conductors and circuit parts 120 V or below,
exposed
Perform infrared thermography and other noncontact inspection outside the restricted approach
boundary
HRC
0
2
Y
Y
2
CB or fused switch operation with enclosure doors
open
Perform infrared thermography and other noncontact inspection outside the restricted approach
boundary
1
2
Opening hinged covers (to expose bare, energized
electrical conductors and circuit parts)
3
Open hinged covers (to exposed bare, energized
electrical conductors and circuit parts)
2
Removal of bolted cover (to expose bare, enenergized electrical conductors and circuit parts)
4
3
Removal of bolted covers (to exposed bare,
1
energized electrical conductors and circuit parts)
Work on energized electrical conductors and circuit
parts of utilization equipment fed directly by a
Y
Y
1
branch circuit of the panelboard
Panelboards or Other Equipment Rated >240V and up to 600V (with molded or
insulated case circuit breakers) - Note 1
Arc Flash Boundary = 30 in.
Work on energized electrical conductors and circuit
parts, including voltage testing
Y
Y
2
Work on energized electrical conductors and circuit
parts, including voltage testing
Y
Y
4
Work on control circuits with energized electrical
conductor and circuit parts >120 V, exposed
Y
Y
2
Work on control circuits with energized electrical
conductor and circuit parts >120 V, exposed
Y
Y
4
Application of temporary safety grounds, after
voltage test
Y
2
Insertion or removal (racking) of CBs from cubicles,
doors open or closed
Task (equipment is energized & work is done
within the flash protection boundary)
Insertion or removal (racking) of CBs from cubicles,
doors open or closed
4
Application of temporary safety grounds, after
voltage test
Removal of bolted covers (to exposed bare,
energized electrical conductors and circuit parts)
4
Opening voltage transformer or control power
transformer compartments
V-Rated
Gloves
V-Rated
Tools
HRC
Circuit Breaker (CB) or fused switch operation with
covers on
0
Open hinged covers (to exposed bare, energized
electrical conductors and circuit parts)
0
Removal of bolted covers (to exposed bare,
energized electrical conductors and circuit parts)
Perform infrared thermography and other noncontact inspection outside the restricted approach
boundary
1
1
CB or fused switch operation with
covers off
Y
Work on energized electrical conductors and circuit
parts, including voltage testing
Y
Y
2
Y
Y
2
Remove/install CBs or fused switches
Work on energized electrical conductors and circuit
parts of utilization equipment fed directly by a
branch circuit of the panelboard or Switchboard
1
Y
Y
2
600V Class Motor Control Center (MCCs) - Note 2
Arc Flash Boundary = 53 in
Task (equipment is energized & work is done
within the flash protection boundary)
V-Rated
Gloves
V-Rated
Tools
HRC
CB or fused switch or starter operation with
enclosure doors closed
0
Reading a panel meter while operating a meter
switch
0
Work on control circuits with energized electrical
conductors and circuit parts 120 V or below,
exposed
Perform infrared thermography and other noncontact inspection outside the
restricted approach boundary
Y
Y
CB or fused switch or starter operation with
enclosure doors open
Y
Work on control circuits with energized electrical
conductor and circuit parts >120 V, exposed
Y
Application of safety grounds, after voltage test
Work on energized electrical conductors and circuit
parts of utilization equipment fed directly by a
branch circuit of the motor control center
Y
Y
Y
Y
V-Rated
Gloves
V-Rated
Tools
Insertion or removal of individual starter “buckets”
from MCC
Y
Removal of bolted covers (to exposed bare,
energized electrical conductors and circuit parts)
Miscellaneous Equipment cover removal or
installation
Opening hinged covers (to expose bare, energized
electrical conductors and circuit parts) - Lighting or
small power transformer (600v max)
Work on energized electrical conductors and circuit
parts, including voltage testing - Lighting or small
power transformer (600v max)
Y
Y
2
2
2
4
2
Work on energized electrical conductors and circuit
parts, including voltage testing
Y
Work on control circuits with energized electrical
conductor - and circuit parts >120 V, exposed
2
2
2
V-Rated
Tools
HRC
Y
Y
Y
* If the notes cannot be satisfied, work must be performed
de-energized
Note 1 Maximum of 25 kA short circuit current available,
maximum of 0.03 second (2 cycle) fault clearing time.
Work on energized electrical conductors and circuit
parts, including voltage testing
Insertion or removal (racking) of CBs from cubicles,
doors open or closed
Removal of bolted cover (to expose bare,
energized electrical-cal conductors and circuit
parts)
Y
Y
2
4
Insertion or removal of CBs from cubicles, doors
open
Other Equipment Including Metal-Enclosed Interrupter Switchgear, Fused or
Unfused 1 kV Thru 38 kV - Note 5
Arc Flash Boundary = 422 in. (35' 2")
Task (equipment is energized & work is done
within the flash protection boundary)
V-Rated
Gloves
V-Rated
Tools
Metal -enclosed Interupter Switchgear, Fused
or Unfused
Switch operation of arc-resistant-type construction,
tested in accordance with IEEE C37.20.7, doors
closed only
HRC
0
2
Switch operation , doors closed
Y
Y
4
Opening hinged covers (to expose bare, energized
electrical conductors and circuit parts)
3
0
Outdoor disconnect switch operation
(hookstick operated)
Y
0
Outdoor disconnect switch operation (gangoperated, from grade)
Y
2
0
Insulated cable examination, in manhole or
other confined space
Y
4
Y
2
Insulated cable examination, in open area
Task (equipment is energized & work is done
within the flash protection boundary)
3
Work on energized electrical conductors and circuit
parts, including voltage testing where arcing
current is >1 kA and <4 kA. - Potential arc flash
boundary using above parameters at 4 kA: 36 in.
4
4
4
Y
3
Storage Batteries, Direct-Currenty Switchboards and Other Direct-Curent
Supply Sources >100 v < 250 V
Maximum Arc Duration and Working Distance 2 sec @ 18 in.
3
3
Y
Y
0
Application of temporary safety grounds, after
voltage test
NOTES
0
4
3
Y
Insertion or removal (racking) of CBs from cubicles,
doors closed
Work on control circuits with energized electrical
conductors and circuit parts 120 V or below,
exposed
Removal of bolted cover (to expose bare,
energized electrical conductors and circuit parts)
2
Y
HRC
0
CB operation with enclosure doors closed
Work on energized electrical conductors and circuit
parts, including voltage testing
V-Rated
Gloves
Opening hinged covers (to expose bare, energized
electrical-cal conductors and circuit parts)
Perform infrared thermography and other noncontact inspection outside the restricted approach
boundary
V-Rated
Tools
0
2
Contactor operation with enclosure doors open
V-Rated
Gloves
Insertion or removal (racking) voltage trans-former
on or off the bus door closed
2
HRC
Task (equipment is energized & work is done
within the flash protection boundary)
1
Y
Contactor operation with enclosure doors closed
Insertion or removal (racking) of starters from
cubicles of arc-resistant construction, tested in
accordance with IEEE C37.20.7, doors closed only
CB operation with enclosure doors open
Arc-Resistant Switchgear Type 1 or 2 (for clearing times of <0.5 sec with a
perspective fault current not exceed the arc resistant rating of equipment)Note 5
Arc Flash Boundary = 422 in. (35' 2")
0
Revenue meters (kW-hour, at primary voltage and
current) Insertion or removal
Removal of bolted cover (to expose bare,
energized electrical conductors and circuit parts) Lighting or small power transformer (600v max)
Task (equipment is energized & work is done
within the flash protection boundary)
Work on control circuits with energized electrical
conductors and circuit parts 120 V or below,
exposed
4
Insertion or removal (racking) of ground and test
device with doors closed
2
Y
4
1
Y
Reading a panel meter while operating a meter
switch
4
HRC
Application of safety grounds, after voltage test Lighting or small power transformer (600v max)
Y
Y
4
1
Cable trough or tray cover removal or installation
Insertion or removal of plug-in devices into or from
Y
busways
NEMA E2 (fused contactor) Motor Starters, 2.3kV thru 7.2kV
Note 5
Arc Flash Boundary = 422 in. (35' 2")
1
Open hinged covers (to exposed bare, energized
electrical conductors and circuit parts)
V-Rated
Tools
1
600V Class Motor Control Center (MCCs) - Note 3
Arc Flash Boundary = 165 in. (13' 9")
Task (equipment is energized & work is done
within the flash protection boundary)
V-Rated
Gloves
Application of temporary safety grounds, after
voltage test
2
Y
Task (equipment is energized & work is done
within the flash protection boundary)
0
1
Work on energized electrical conductors and circuit
parts, including voltage testing
Other 600V Class (277v thru 600v, nominal equipment)
- Note 2 Arc Flash Boundary = 53 in.
4
Work on energized electrical conductors and circuit
parts, including voltage testing where arcing
current is >4 kA and <7 kA. - Potential arc flash
boundary using above parameters at 7 kA: 48 in.
Work on energized electrical conductors and circuit
parts, including voltage testing where arcing
current is >7 kA and <15 kA. - Potential arc flash
boundary using above parameters at 15 kA: 72 in.
V-Rated
Gloves
V-Rated
Tools
HRC
Y
Y
1
Y
Y
2
Y
Y
3
Storage Batteries, Direct-Currenty Switchboards and Other Direct-Curent
Supply Sources >250 v < 600 V
Maximum Arc Duration and Working Distance 2 sec @ 18 in.
V-Rated
Gloves
V-Rated
Tools
HRC
Note 2 Maximum of 65 kA short circuit current available,
maximum of 0.03 second (2 cycle) fault clearing time.
Work on energized electrical conductors and circuit
parts, including voltage testing where arcing
current is >1 kA and <1.5 kA. - Potential arc flash
boundary using above parameters at 1.5 kA: 36 in.
Y
Y
1
Note 3 Maximum of 42 kA short circuit current available,
maximum of 0.33 second (20 cycle) fault clearing time.
Work on energized electrical conductors and circuit
parts, including voltage testing where arcing
current is >1.5 kA and <3 kA. - Potential arc flash
boundary using above parameters at 3 kA: 48 in.
Y
Y
2
Work on energized electrical conductors and circuit
parts, including voltage testing where arcing
current is >3 kA and <7 kA. - Potential arc flash
boundary using above parameters at 7 kA: 72 in.
Y
Y
3
Work on energized electrical conductors and circuit
parts, including voltage testing where arcing
current is >7 kA and <10 kA. - Potential arc flash
boundary using above parameters at 10 kA: 96 in.
Y
Y
4
Note 4 Maximum of 35 kA short circuit current available,
maximum of 0.5 second (30 cycle) fault clearing time.
Note 5 Maximum of 35 kA short circuit current available,
maximum of 0.2 second (12 cycle) fault clearing time.
*Working on circuits over 40 cal/cm2 should be avoided
because of blast hazard.
Task (equipment is energized & work is done
within the flash protection boundary)
Minimum
HRC
cal/cm
Protective Clothing
2
0
Natural fiber long-sleeve shirt & pants
Fabric wt 4.5 oz/yd²
4
1
FR long-sleeve shirt & pants or
FR coveralls
Arc rated face shield,
Rubber insulating gloves (AN)
FR long-sleeve shirt & pants or
FR coveralls
8
2
Arc rated face shield with balaclava or Arc flash hood,
Rubber insulating gloves (AN)
N/A
Definitions: Y = Yes (Required)
Hard Hat, Safety Glasses or Goggles, Hearing Protection, Leather Work
Shoes Apply to All &Leather Gloves(AN)
V-Rated Gloves: Rubber Insulating Gloves rated and tested for the maximum line-to-line
voltage upon which work will be done. Leather protectors must be worn externally if
rubber insulating gloves could be damaged.
Rubber insulating gloves (AN)
3
Arc rated flash suit
25
Arc rated switching hood,
Rubber insulating gloves (AN)
4
Arc rated flash suit
40
Arc rated switching hood,
Rubber insulating gloves (AN)
V-Rated Tools: Insulated and Insulating Hand Tools rated and tested for the maximum lineto-line voltage upon which work will be done
HRC: Hazard Risk Category
FR: Flame Resistant
AN: As Needed
APPROACH BOUNDARIES – AC SYSTEMS
Nominal System Voltage
2
Range, Phase to Phase
Less than 50
50 to 300
301 to 750
751 to 15 kV
15.1 kV to 36 kV
1
2
3
Limited Approach Boundary
Exposed Movable
Exposed Fixed
Circuit
3
Conductor
Part
Not specified
Not specified
10 ft. 0 in.
3 ft. 6 in.
10 ft. 0 in.
3 ft. 6 in.
10 ft. 0 in.
10 ft. 0 in.
5 ft. 0 in.
6 ft. 0 in.
Restricted
Approach Boundary
Includes
Inadvertent
Movement Adder
Not specified
Avoid contact
1 ft. 0 in.
2
2 ft. 2 in.
2
2 ft. 7 in.
Arc Flash Protection Boundary
Prohibited
Approach
Boundary
Not specified
Avoid contact
0 ft. 1 in.
See Each Section
1
Of HRC Guide
0 ft. 7 in.
0 ft. 10 in.
For panelboards only, rated up to 600 volts, set up arc flash boundary at 4 feet to keep unqualified people our of your work area.
For all other situations, set up arc flash boundary at designated distance per HRC Guide.
For single-phase systems, select the range that is equal to the system’s maximum phase-to-ground voltage multiplied by 1.732.
A condition in which the distance between the conductor and a person is not under the control of the person. The term
is normally applied to overhead line conductors supported by poles.
a
APPROACH BOUNDARIES – DC SYSTEMS
Nominal Potential
Difference
< 100V
100 V – 300 V
301 V – 1 kV
1.1 kV – 5 kV
a
b
Limited Approach Boundary
Exposed Movable
Exposed Fixed
Circuit
b
Conductor
Part
Not specified
Not specified
10 ft. 0 in.
3 ft. 6 in.
10 ft. 0 in.
3 ft. 6 in.
5 ft. 0 in.
10 ft. 0 in.
Restricted
Approach Boundary
Includes
Inadvertent
Movement Adder
Not specified
Avoid contact
1 ft. 0 in.
1 ft. 5 in.
Prohibited
Approach
Boundary
Not specified
Avoid contact
0 ft. 1 in.
0 ft. 4 in.
All dimensions are distance from exposed energized electrical conductors or circuit parts to worker.
This term describes a condition in which the distance between the conductor and a person is not under the control of the person.
The term is normally applied to overhead line conductors supported by poles.
APPOROACH BOUNDARIES
ELECTRICAL SHOCK HAZARDS
Limited Approach Boundary: An approach limit at a distance from an exposed energized conductor or circuit part within which a shock
hazard exists. An electrical shock boundary whereby only qualified people can enter because they have the skills and knowledge to
recognize and avoid electrical hazards. Unqualified people must stay outside the Limited Approach Boundary so they cannot contact
energized parts.
Restricted Approach Boundary: The distance from exposed energized parts where there is an increased risk of electrical shock due to
electric arc over combined with inadvertent movement. A qualified person must wear PPE for protection (typically rubber insulating
gloves and use insulated tools) from the electrical shock hazard when working within the Restricted Approach Boundary.
Prohibited Approach Boundary: The distance from an exposed energized electrical conductor or circuit part within which work is
considered the same as making contact with the electrical conductor or circuit part. A qualified person must avoid performing work
with the Prohibited Approach Boundary.
Arc Flash Protection Boundary: The distance from an arc source at which a person could receive a second-degree burn if an electrical
arc flash would occur. All people must wear appropriate PPE while working/standing within this approach boundary.
Unqualified People – Access to Working Space
All unqualified people must stay outside the Limited Approach Boundary and the Arc Flash Protection Boundary, which ever distance is
greater. They must remain outside these approach boundaries until the electrical hazard is eliminated / controlled.
Develop a plan for keeping unqualified people and qualified people not wearing PPE, outside the approach boundary. For large electrical
rooms, cordon off the work area with barricades and signs. Small electrical rooms can be controlled by keeping everyone outside the
electrical room with a closed door and a spotter.
When working in a panel in a hallway of an occupied building, set up a barricade system to keep unqualified people out.
Justification for Work : Staff Electric’s company policy is – NO HOT WORK!
Our policy is to de-energize by placing the energized electrical conductors and circuit parts into an electrically safe work condition to protect
exposed employees working within the Limited Approach Boundary. Staff Electric follows the requirements of NFPA 70E and OSHA for
justifying hot work.
NFPA 70E 130.2 Energized electrical conductors and circuit parts to which an employee might be exposed shall be put into an
electrically safe work condition before an employee performs work:
1. Within the limited approach boundary or
2. The employee interacts with equipment where conductors or circuit parts are not exposed, but an increased risk of injury
from an exposure to an arc flash hazard exists.
The only exceptions are:
1. Greater Hazard: The employee can demonstrate that de-energizing introduces hazards.
2. Infeasibility: The employee can demonstrate that the task to be performed is infeasible in a de-energized state due to the
equipment design or operational limitations.
3. Less than 50 volts to ground.
OSHA’s position regarding hot work is:
OSHA 1910.333(a)(1) requires that live parts be de-energized before a potentially exposed employee works on or near them. Exception - if
de-energizing introduces additional or increased hazards or if de-energizing is infeasible due to equipment design or operational limitations.
Examples are:
•
•
•
•
Interruption of life support equipment
Deactivation of emergency alarm systems
Shutdown of hazardous location ventilation
equipment
Removal of illumination from an area
•
Performing diagnostics and testing (e.g. start up and
trouble shooting circuits that are part of a continuous
process that would otherwise need to be completely
shutdown in order to permit work on 1 circuit or
piece of equipment.)
2012 Edition