Arc Flash Task Table - NFPA 70E-2015


The “Task Tables” included in NFPA 70E and Canada’s CSA Z462 can be a helpful guide to evaluating the potential hazards you might face when working on an electrical system. The tables present a series of examples of potential tasks that have been reviewed, factoring both the level of hazard and the risk of incident.


We can not stress enough the importance of owning a copy of NFPA 70E (available in English or Spanish) or the Canadian CSA Z462 (available in English or French). The standards should be used as a guide in establishing your facilities’ electrical safe work practices and PPE, covering anyone working on or near energized equipment or systems.


A copy of NFPA 70E can be purchased at http://www.nfpa.org/catalog/
A copy of CSA Z462 can be purchased at http://shop.csa.ca/


Hard copies of either standard can also be purchased directly from Oberon. Contact Oberon Customer Service for pricing and details.


As a convenience, Oberon has created a web based version of the task tables to assist in evaluating your needs. This is only one of several methods available to you to assist your efforts. Included on this site is a web based version of the Heat Flux Calculator. Visit the FAQ section of this website to learn about other methods available to you. Please refer to your full edition of the standard for other important information


Please be aware of the important notes that follow the table


ADDITIONAL NOTE: The tasks identified in this table (from the NFPA 70E and CSA Z462 standards) are examples of tasks with calculations based upon specific conditions that may not be equivalent to yours. Conditions that vary from those used in these calculations could dramatically change the result. Please use caution when referring to this table.


To begin, select one of the example tasks listed



Reading a panel meter while operating a meter switch
Equipment Condition: Any
Normal operation of a circuit breaker (CB), switch, contactor, or starter
Equipment Condition: All of the following:
• The equipment is properly installed.
• The equipment is properly maintained.
• All equipment doors are closed and secured.
• All equipment covers are in place and secured.
• There is no evidence of impending failure
Normal operation of a circuit breaker (CB), switch, contactor, or starter
Equipment Condition: One or more of the following:
• The equipment is not properly installed.
• The equipment is not properly maintained.
• All equipment doors are open or not secured.
• All equipment covers are off or not secured.
• There is evidence of impending failure
For ac systems: Work on energized electrical conductors and circuit parts, including voltage testing
Equipment Condition: Any
For dc systems: Work on energized electrical conductors and circuit parts of series-connected battery cells, including voltage testing
Equipment Condition: Any
Voltage testing on individual battery cells or individual multi-cell units
Equipment Condition: All of the following:
• The equipment is properly installed.
• The equipment is properly maintained.
• All equipment doors are closed and secured.
• All equipment covers are in place and secured.
• There is no evidence of impending failure
Voltage testing on individual battery cells or individual multi-cell units
Equipment Condition: One or more of the following:
• The equipment is not properly installed.
• The equipment is not properly maintained.
• All equipment doors are open or not secured.
• All equipment covers are off or not secured.
• There is evidence of impending failure
Removal or installation of CBs or switches
Equipment Condition: Any
Removal or installation of covers for equipment such as wireways, junction boxes, and cable trays that does not expose bare energized electrical conductors and circuit parts
Equipment Condition: All of the following:
• The equipment is properly installed.
• The equipment is properly maintained.
• All equipment doors are closed and secured.
• All equipment covers are in place and secured.
• There is no evidence of impending failure
Removal or installation of covers for equipment such as wireways, junction boxes, and cable trays that does not expose bare energized electrical conductors and circuit parts
Equipment Condition: One or more of the following:
• The equipment is not properly installed.
• The equipment is not properly maintained.
• All equipment doors are open or not secured.
• All equipment covers are off or not secured.
• There is evidence of impending failure
Removal of bolted covers (to expose bare energized electrical conductors and circuit parts). For dc systems, this includes bolted covers, such as battery terminal covers.
Equipment Condition: Any
Removal of battery intercell connector covers All of the following:
Equipment Condition: All of the following:
• The equipment is properly installed.
• The equipment is properly maintained.
• All equipment doors are closed and secured.
• All equipment covers are in place and secured.
• There is no evidence of impending failure
Removal of battery intercell connector covers All of the following:
Equipment Condition: One or more of the following:
• The equipment is not properly installed.
• The equipment is not properly maintained.
• All equipment doors are open or not secured.
• All equipment covers are off or not secured.
• There is evidence of impending failure
Opening hinged door(s) or cover(s) (to expose bare energized electrical conductors and circuit parts)
Equipment Condition: Any
Perform infrared thermography and other noncontact inspections outside the restricted approach boundary. This activity does not include opening of doors or covers.
Equipment Condition: Any
Application of temporary protective grounding equipment after voltage test
Equipment Condition: Any
Work on control circuits with exposed energized electrical conductors and circuit parts, 120 volts or below without any other exposed energized equipment over 120 V including opening of hinged covers to gain access
Equipment Condition: Any
Work on control circuits with exposed energized electrical conductors and circuit parts, greater than 120 V
Equipment Condition: Any
Insertion or removal of individual starter buckets from motor control center (MCC)
Equipment Condition: Any
Insertion or removal (racking) of CBs or starters from cubicles, doors open or closed
Equipment Condition: Any
Insertion or removal of plug-in devices into or from busways
Equipment Condition: Any
Insulated cable examination with no manipulation of cable
Equipment Condition: Any
Insulated cable examination with manipulation of cable
Equipment Condition: Any
Work on exposed energized electrical conductors and circuit parts of equipment directly supplied by a panelboard or motor control center
Equipment Condition: Any
Insertion and removal of revenue meters (kW-hour, at primary voltage and current)
Equipment Condition: Any
For dc systems, insertion or removal of individual cells or multi-cell units of a battery system in an enclosure
Equipment Condition: Any
For dc systems, insertion or removal of individual cells or multi-cell units of a battery system in an open rack
Equipment Condition: Any
For dc systems, maintenance on a single cell of a battery system or multi-cell units in an open rack
Equipment Condition: Any
For dc systems, work on exposed energized electrical conductors and circuit parts of utilization equipment directly supplied by a dc source
Equipment Condition: Any
Arc-resistant switchgear Type 1 or 2 (for clearing times of <0.5 sec with a prospective fault current not to exceed the arc-resistant rating of the equipment) and metal enclosed interrupter switchgear, fused or unfused of arc resistant type construction, tested in accordance with IEEE C37.20.7:
• Insertion or removal (racking) of CBs from cubicles
• Insertion or removal (racking) of ground and test device
• Insertion or removal (racking) of voltage transformers on or off the bus
Equipment Condition: All of the following:
• The equipment is properly installed.
• The equipment is properly maintained.
• All equipment doors are closed and secured.
• All equipment covers are in place and secured.
• There is no evidence of impending failure
Arc-resistant switchgear Type 1 or 2 (for clearing times of <0.5 sec with a prospective fault current not to exceed the arc-resistant rating of the equipment) and metal enclosed interrupter switchgear, fused or unfused of arc resistant type construction, tested in accordance with IEEE C37.20.7:
• Insertion or removal (racking) of CBs from cubicles
• Insertion or removal (racking) of ground and test device
• Insertion or removal (racking) of voltage transformers on or off the bus
Equipment Condition: One or more of the following:
• The equipment is not properly installed.
• The equipment is not properly maintained.
• All equipment doors are open or not secured.
• All equipment covers are off or not secured.
• There is evidence of impending failure
Opening voltage transformer or control power transformer compartments
Equipment Condition: Any
Outdoor disconnect switch operation (hookstick operated) at 1 kV through 15 kV
Equipment Condition: Any
Outdoor disconnect switch operation (gang-operated, from grade) at 1 kV through 15 kV
Equipment Condition: Any


*The phrase properly installed, as used in this table, means that the equipment is installed in accordance with applicable industry codes and standards and the manufacturer’s recommendations. The phrase properly maintained, as used in this table, means that the equipment has been maintained in accordance with the manufacturer’s recommendations and applicable industry codes and standards. The phrase evidence of impending failure, as used in this table, means that there is evidence of arcing, overheating, loose or bound equipment parts, visible damage, deterioration, or other damage