Arc Flash

Frequently Asked Questions.

Q. What are some of the causes of an Electrical Arc Flash?

1. Dust and impurities on insulating surfaces can provide a path for current
allowing it to flashover and create an arc discharge across the surface.

2. Condensation of vapor and water dripping can cause tracking on the
surface of insulating materials, this can create a flashover to ground and
potential escalation to phase to phase arcing.

3. Spark Discharge.

4. Accidental touching (i.e. during trouble shooting procedures).

5. Dropping tools (also during troubleshooting).

6. Over-Voltages across narrow gaps.

7. Failure of insulating materials.

8. Improperly designed or utilized equipment.

9. Improper work procedures.

Q. What are the hazards from an arc flash?

Arching faults release dangerous levels of radiant heat energy, capable of
causing severe burns. Fatal burns can occur up to five feet from the arc,
with severe burns up to ten feet away. Arcs produce some of the highest
temperatures known to occur on earth; up to 35,000 degrees Fahrenheit.
This is 4 times the surface temperature of the sun. Clothing can be ignited
several feet away. Blast shrapnel can be distributed over a wide area. Arcs
spray droplets of molten metal with the explosion distributing the molten
metal produced by the arc over a large area.
The vaporization of metal and heating of the air produces blast pressure
waves that have thrown workers across rooms and knocked them off
Hearing loss from the sound blast.

Q. What is the impact of an arc flash?

Treatment can require years of skin grafting and rehabilitation.
Victim may never return to work or regain quality of life.
Victim may DIE.
Cost of treatment can exceed $1,000,000/case.
Potential litigation fees.
Potential loss of process.
Potential fines.
Escalation of Insurance.

Q. What is the Electrical insdustry doing to address the Arc Flash issue?

The 2002 NEC Article 110.16 requires field marking of potential arc flash
hazards for panels likely to be serviced or examined in an energized
condition. This article contains a fine print note (FPN) regarding proper
signage and an FPN referencing NFPA 70E, OSHA 1910.131(d) and 1926.28(a)
states, the employer is responsible to assess the hazards in the work
place, select, have, and use the correct Personal Protective Equipment
(PPE) and document the assessment.
OSHA is now in the process of revising 1910.302-.308 to be consistent with
the NFPA 70E 2000. Part 1 Revision.

(A sample of the required label can be seen below)

Q. What does NFPA-70E do to address arc flash hazards?

It defines a series of BOUNDRIES related to electrical safety when working
on energized equipment.

Flash Protection Boundary
 Limited Approach Boundary
Restricted Approach Boundary
 Prohibited Approach Boundary

Determining Flash Protection Boundaries may be based on voltage,
available short circuit current and predicted fault duration.

NFPA 70E provides THREE acceptable methods of determining flash
protection boundary:

1. Simplified Table 220.2(b)(2), 220.6(b) (9)
2. Analysis based on NFPA 70E Annex B.
3. Analysis based on IEEE-1584 Standards.


More realistic risk assessment.
Helps insure worker safety.
Increases compliance by workers compared to conservative blanker rules.
Self-Documenting---helps assure compliance with safety standards.
Can result in worker productivity,saving thousands of dollars on annnual

Q. How does a company go about reducing risk and exposure to arc flash

1. Acknowledge there is a hazard.
2. Assess the magnitude of the hazard.
3. Develop an Arc Flash Hazard program.
4. Avoid working on or near exposed energized equipment.
5.Develop Personal Protective Equipment Plan.
6. Provide training for workers on safety procedure and protective gear.
7. Where exposure cannot be avoided implement safety procedures to
minimize dangers.
8. Establish ongoing programs to help insure workers within danger zone
are appropriately protected with suitable PPE.
9. Develop, Document and implement safety procedures.


Q. What does an Arc Flash hazard program consist of.

1. Hazard Assessment
2. Documentation
3. Personal Protective Equipment Plan
4. Development of Procedures to minimize hazard
5. Training for workers
6. Continual improvement
7. Safety Audit
8. Corporate-Wide Plan

Q. I'd like to get my Arc Flash program underway, where do I begin?

1. Have an Arc Flash hazard analysis done with proper labeling and
documentation to be compliant with OSHA, NEC, and NFPA 70E standard.
2. Perform Arc Flash Hazard training with information on the latest
standards of practices.
3. Review safety program and integrate Arc Flash.
4. Select Personal Protective Equipment Vendor.
5. Implement your Arc Flash Hazard safety program.
6. Continue ongoing program tracking, documentation improvements and

Meeting the challenge of the new Arc Flash safety requirements requires
resources familiar with standards, experts' assistance in power
engineering & partners experiences in today's operational realities.

SOUTHERN SUBSTATION is uniquely qualified to help you develop,
structure and implement a complete, cost effective arc flash solution for
your plant of facility. Our engineering teams can help you craft arc flash
solutions that provide the required worker safety and regulatory
compliance while you're coping with fewer resources and constrained

Arc Flash, the latest addition to the array of capabilities at SOUTHERN
SUBSTATION insures compliance with OSHA, NFPA 70E, and IEEE-1584
safety standards. It includes everything you need to develop a complete
plan - right down to the ability to output warning labels.
Let us help you identify and implement cost effective solutions that
prevent costly over protection and decreased worker productivity.

Contact Southern Substation today for an expert response to arc flash
safety requirement.
       How is an arc flash analysis performed

Southern Substation will perform an arc flash hazard analysis at your plant.
The analysis is conducted as follows: Southern Substation will furnish a two
man team to do the survey. This team will do a physical survey of your plant
beginning at the incoming utility and moving thru your plant looking at all
switchgear, MCC's, Panelboards, and industrial control panels, any piece of
equipment 240 volts and up, as they perform the survey they will be
numbering everything they look at using a dymo labeler (this is because when
the arc flash labels are printed they will have a corresponding number. That
way no labels are put on wrong). There is no need to de-energize any
equipment during the process. Some of the information they will be gathering
are: Voltage, Amperage, Current rating, Wire & Cable sizes, Length of run,
also they will be looking at breaker types and trips unit settings. The gathered
data will be used to perform caculations for Fault current (KA), Arcing current
(KA), Incident energy (cal/cm2), Protective Boundary, Category of Personal
Protective Equipment required at each piece of equipment 240 volts & up.

If you have any one line diagrams or any other written/printed material that
has to do with your electrical distribution system it will be a big help if you will
allow the crew access to these items. If any panels need to be opened during
the survey, the crew will need assistance from your personal to do so, also we
will need to have a point of contact to answer any questions that may arise
during the survey. (it is not necessary to have someone with the crew every
minute). Also our crew will provide their own PPE to use onsite.

Southern Substation will then generate and affix the necessary labels to
electrical panels as per 2005 NEC article 110.16 requirements & to coform
with NFPA 70E. Showing the Flash boundary, Incident Energy, Working
Distance, Required PPE level, Shock hazard voltage, Limited approach,
Restricted approach & Prohibited approach.

Perform a training seminar to all employees you require, covering arc flash
hazards, causes and what can be done to protect workers, it includes a 45
slide power point presentation. It also includes instruction on how to read and
understand the arc flash labels and instruction on PPE and its use and care.
The training last for about 1.5 hours depending on attendee participation. We
are willing to hold multiple classes up to 3 sessions to make sure everyone
who needs to attend is able. Also we do not limit class sizes and everyone who
attends receives a certificate of completion for attending. (this can be used to
satisfy OSHA's requirement for employee training). We also recommend that if
you have any safety people or first responders and production supervisors (to
give them a better understanding of the risks involved) that they attend
training as well. We offer to return on an annual basis to give the training, this
will allow us to re-certify the people already trained and teach them on
anything new that may have come out in the previous year, and to catch any
new hires.