NFPA 70E COMPLIANCE GUIDE
2
2
This guide shall only be used in conjunction with performing the necessary calculations in a flash hazard analysis to determine the proper cal/cm . If the results of the calculations exceed the cal/cm 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
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) - Note 4
HRC
Task (equipment is energized & work is done
within the flash protection boundary)
V-Rated
Gloves
V-Rated
Tools
HRC
Task (equipment is energized & work is done
within the flash protection boundary)
V-Rated
Gloves
V-Rated
Tools
HRC
0
CB or fused switch or starter operation with
enclosure doors closed
0
Insertion or removal (racking) of CBs from cubicles,
doors open or closed
4
Circuit Breaker (CB) or fused switch operation with
covers on
0
Reading a panel meter while operating a meter
switch
0
Removal of bolted cover (to expose bare, energized
electrical-cal conductors and circuit parts)
4
CB or fused switch operation with
covers off
0
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
Removal of bolted covers (to exposed bare,
energized electrical conductors and circuit parts)
Work on energized electrical conductors and circuit
parts of utilization equipment fed directly by a
branch circuit of the panelboard
Task (equipment is energized & work is done
within the flash protection boundary)
CB or fused switch operation with enclosure doors
open
Perform infrared thermography and other noncontact inspection outside the restricted approach
boundary
1
2
Y
Y
1
Open hinged covers (to exposed bare, energized
electrical conductors and circuit parts)
1
Work on energized electrical conductors and circuit
parts, including voltage testing
Y
Y
2*
1
Work on control circuits with energized electrical
conductor and circuit parts >120 V, exposed
Y
Y
2*
Y
Y
V-Rated
Gloves
V-Rated
Tools
HRC
Perform infrared thermography and other noncontact inspection outside the restricted approach
boundary
1
CB or fused switch operation with
covers off
Y
Work on energized electrical conductors and circuit
parts, including voltage testing
Work on energized electrical conductors and circuit
parts of utilization equipment fed directly by a
branch circuit of the panelboard or Switchboard
Y
Y
2*
Y
Y
2*
1
600V Class Motor Control Center (MCCs) - Note 2
(except as indicated)
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
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
0
Y
Y
0
1
CB or fused switch or starter operation with
enclosure doors open
1
Open hinged covers (to exposed bare, energized
electrical conductors and circuit parts)--Note 3
1
Work on energized electrical conductors and circuit
parts, including voltage testing
Y
Y
2*
Work on control circuits with energized electrical
conductor and circuit parts >120 V, exposed
Y
Y
2*
Insertion or removal of individual starter “buckets”
from MCC--Note 3
Removal of bolted covers (to exposed bare,
energized electrical conductors and circuit parts)-Note 3
Y
Y
Y
2*
Y
2*
4
4
2
Y
Definitions: Y = Yes (Required)
V-Rated Tools: Insulated and Insulating Hand Tools rated and tested for the
maximum line-to-line voltage upon which work will be done
HRC: Hazard Risk Category
FR: Flame Resistant
AN: As Needed
0
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
2
Y
Y
2
3
4
Removal of bolted cover (to expose bare, enenergized electrical conductors and circuit parts)
4
Removal of bolted covers (to exposed bare,
energized electrical conductors and circuit parts)
4
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
4
Other 600V Class (277v thru 600v, nominal equipment)
- Note 2 (except as indicated)
Task (equipment is energized & work is done
within the flash protection boundary)
V-Rated
Gloves
V-Rated
Tools
HRC
1
Cable trough or tray cover removal or installation
Miscellaneous Equipment cover removal or
installation
1
Opening hinged covers (to expose bare, energized
electrical conductors and circuit parts) - Lighting or
small power transformer (600v max)
1
Y
Application of safety grounds, after voltage test Lighting or small power transformer (600v max)
Y
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)
Y
Work on energized electrical conductors and circuit
parts, including voltage testing
Y
Application of safety grounds, after voltage test
Insertion or removal of plug-in devices into or from
busways
Y
2*
2*
Y
Y
4
4
Opening voltage transformer or control power
transformer compartments
4
2*
HRC
Y
Y
0
0
0
0
2*
3
3
Y
0
CB operation with enclosure doors closed
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
0
Y
Y
Other Equipment Including Metal-Enclosed Interrupter Switchgear, Fused or
Unfused 1 kV Thru 38 kV
Task (equipment is energized & work is done
within the flash protection boundary)
Switch operation of arc-resistant-type construction,
tested in accordance with IEEE C37.20.7, doors
closed only
V-Rated
Gloves
V-Rated
Tools
2
Switch operation , doors closed
Outdoor disconnect switch operation (gangoperated, from grade)
Insulated cable examination, in open area
Y
2
Y
2
3
Opening hinged covers (to expose bare, energized
electrical conductors and circuit parts)
Outdoor disconnect switch operation (hookstick
operated)
3
Work on energized electrical conductors and circuit
parts, including voltage testing
3
Removal of bolted cover (to expose bare, energized
electrical conductors and circuit parts)
4
Insulated cable examination, in manhole or other
confined space
HRC
0
Y
Y
3
Y
Y
4
4
Y
Hard Hat, Safety Glasses or Goggles, Hearing Protection, Leather Work
Shoes and Leather Gloves Apply to All
* If the notes cannot be satisfied, work must be performed de-energized
0
Natural fiber long-sleeve shirt & pants
FR long-sleeve shirt & pants or
FR coveralls
4
1
Arc rated face shield,
Rubber insulating gloves (AN)
Note 1 Maximum of 25 kA short circuit current available, maximum of 0.03
second (2 cycle) fault clearing time.
FR long-sleeve shirt & pants or
FR coveralls
8
2
Arc rated face shield with balaclava or Arc flash hood,
Rubber insulating gloves (AN)
Note 2 Maximum of 65 kA short circuit current available, maximum of 0.03
second (2 cycle) fault clearing time.
FR long-sleeve shirt & pants or
FR coveralls
8
2*
Arc rated face shield with balaclava or Arc flash hood,
Rubber insulating gloves (AN)
Note 3 Maximum of 42 kA short circuit current available, maximum of 0.33
second (20 cycle) fault clearing time.
3
Arc rated flash suit over FR coveralls
or FR long-sleeve shirt & pants
25
Arc rated switching hood,
Rubber insulating gloves (AN)
Note 4 Maximum of 35 kA short circuit current available, maximum of 0.5
second (30 cycle) fault clearing time.
4
Arc rated flash suit over FR coveralls
or FR long-sleeve shirt & pants
40
Arc rated switching hood,
Rubber insulating gloves (AN)
Rubber insulating gloves (AN)
2
4
Insertion or removal of CBs from cubicles, doors
open
V-Rated
Tools
Y
HRC
0
V-Rated
Gloves
Y
V-Rated
Tools
Insertion or removal (racking) voltage trans-former
on or off the bus door closed
2*
Y
V-Rated
Gloves
2*
Y
Perform infrared thermography and other noncontact inspection outside the restricted approach
boundary
Task (equipment is energized & work is done
within the flash protection boundary)
0
2*
Reading a panel meter while operating a meter
switch
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)
Insertion or removal (racking) of ground and test
device with doors closed
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
Work on control circuits with energized electrical
conductor - and circuit parts >120 V, exposed
Application of safety grounds, after voltage test
2*
NEMA E2 (fused contactor) Motor Starters, 2.3kV thru 7.2kV
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 CBs from cubicles,
doors open or closed
CB operation with enclosure doors open
Work on energized electrical conductors and circuit
parts, including voltage testing - Lighting or small
power transformer (600v max)
Work on energized electrical conductors and circuit
parts, including voltage testing
N/A
V-Rated
Tools
Insertion or removal (racking) of CBs from cubicles,
doors open or closed
Y
cal/cm2
V-Rated
Gloves
3
Application of safety grounds, after voltage test
Minimum
Task (equipment is energized & work is done
within the flash protection boundary)
Opening hinged covers (to expose bare, energized
electrical conductors and circuit parts)
Opening hinged covers (to expose bare, energized
electrical-cal conductors and circuit parts)
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.
Metal Clad Switchgear, 1 kV thru 38 kV
2*
Application of safety grounds, after voltage test
Contactor operation with enclosure doors open
Protective Clothing
0
1
0
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
Circuit Breaker (CB) or fused switch operation with
covers on
Task (equipment is energized & work is done
within the flash protection boundary)
Y
Y
Panelboards or Switchboards Rated >240V and up to 600V (with molded or
insulated case circuit breakers) - Note 1
HRC
NEMA E2 (fused contactor) Motor Starters, 2.3kV thru 7.2kV - CONTINUED
*Working on circuits over 40 cal/cm2 should be avoided
because of blast hazard.
4
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
Limited Approach Boundary
Exposed Movable
Exposed Fixed Circuit
3
Conductor
Part
Not specified
Not specified
Restricted Approach
Boundary Includes
Inadvertent Movement
Adder
Not specified
Prohibited Approach
Boundary
Not specified
Avoid contact
0 ft. 1 in.
4 ft. 0 in.
1
4 ft. 0 in.
0 ft. 7 in.
0 ft. 10 in.
40 ft. 0 in.
4
40 ft. 0 in.
10 ft. 0 in.
10 ft. 0 in.
3 ft. 6 in.
3 ft. 6 in.
Avoid contact
1 ft. 0 in.
10 ft. 0 in.
10 ft. 0 in.
5 ft. 0 in.
6 ft. 0 in.
2 ft. 2 in.
2
2 ft. 7 in.
2
Arc Flash Protection Boundary
(Panelboards Only)
Not specified
1
4
In the absence of a engineering calculation, use 4 feet (for panelboards only) when the product of clearing time of 2
cycles (.033 sec) and the available bolted fault current of 50 ka or any combination not exceeding 100 ka cycles.
When the product of clearing times and bolted fault current exceeds 100 ka cycles, then do the calculation. This 4 feet rule
applies only to panelboards, not MCC’s and switchgear. An arc flash protection boundary calculation should be done for
MCC’s and switchgear operations.
For single-phase systems, select the range that is equal to the system’s maximum phase-to-ground voltage multiplied by 1.732.
3
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.
4
In the absence of arc flash boundary calculations on equipment labeling, default to 40 feet.
APPOROACH BOUNDARIES
ELECTRICAL SHOCK HAZARDS
Limited Approach Boundary: 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 (130.1): 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 130.1(A) 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 works within the Limited Approach Boundary of those conductors or
parts.
The only exceptions are:
1. Greater Hazard: The employee can demonstrate that de-energizing introduces additional or increased 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.)